Hi-Performance Straight Eights

7 posts in this topic

Thought I would try and jumpstart a discussion about Hi-Performance Straight Eights.

Here's hoping the Team Buick fellers don't mind me borrowing this great thread from several years ago. Actual thread can be found here

With my limited knowledge of engines and especially straight 8's, I got lost in some of the conversation and it does get wordy every once in awhile but the knowledge and experiences shared is awesome.

Please comment or feel free to start your own thread about Straight 8 Hi-Performance builds


12-23-2005, 02:49 PM
Alleycat, I am curious as what kind of mods have you done on the cranks in your hi-perf 320 engines? How does the standard crank hold up with high revs? I would also like you to unveil the secrets of the rods you have used! The rod length is so extreme that I haven't found any contemporary performance rods that could be adopted. And what about pistons - I bet you have had some custom pistons made just for you, right?
12-24-2005, 07:05 PM
Ha! Kinda wondering when someone was going to ask some serious questions. I've built only 1 320, my 248 a number of times and currently favor the 263 as the best of the bunch. The 320 and 248 are basicly the same engine, just bigger or smaller depending on your viewpoint. The 263 is a totaly moderen engine and as such has far and away more modification potential, the things that can be done to these is unbeliveable. The cranks are forged steel, a very good unit. Tape up the journals, get out your 41/2" and grind off all the forging flash, index notches and general junk hung on the unit, don't take off the sharp edge around the journals where the crank arm transitions from the journal, this edge help fling oil. Get out your die grinder, various flap wheels and polish all rough surfaces to a 320 grit or so. At this point it is pretty darn good, however, if you want that last yard, take it to a plating outfit and have it buffed. Lastly, send it out to a crank grinder with the newest grinder and a guy that knows what he's doing. It's done. The rods are forged and not bad units,the bolts are the only thing that could use a update, as metals technology is vastly improved. However, rods and bolts only fail in tension, not compression, and tension comes with lots of rpm's. Something that we'll never get with str8's. The rod can be beam polished, sharp edges around the bolt head and nut flats smoothed and polished and then shot peened. You MUST be VERY carefull about who does the shot peening as some of these guys can DESTROY your rods, check and double check who you give your rods to. Pistons. Absolutly, hands down the BIGGEST problem with str8's. These engines need a moderen hyperutectic piston design badly. We're probably not going to get it. As such, I've had to be very creative. The buick piston is not a bad design. I thought that it was' ent, piston design of the '60's influenced me. Turns out that the buick design is probably better than even the boys at buick knew. That said, the alloy is 2024, hard anodized and very long, not good. The replacements are not even that good. If you have oversize genuine buick pistons its the best short of customs. I've even put harley davidson 74" in my 263, in order to address the problem. Not the correct dome but it's experimental. So what to do? Stock pistons, first, aftermarket, second. In all cases, polish the top, leaving no imperfections, buff it till it looks like chrome. Moly rings are nice, if you can find 'em. Just shy of a mirror finish on the walls, none of this generic 280 grit hone stuff the rebuilders want to put on, "it'll never seat". Bull. What it'll do is eat the rings and walls up. Been there done that. Lastly, str8's will never turn over 4100 rpm, even with my best all out head. And, you don't want to go more, at this point inertial problems are going to get out of hand, fast. You'll be throwing engine parts into the back of your pickup and towing it home.... This should give ya' something to think about. alleycat.
chub chub
12-24-2005, 08:33 PM
Here's a couple links to other discussions about Buick straight 8's. these are pretty amazing. You'll even find links back to Jyrkis site.
12-30-2005, 02:19 PM
Well, finally past the X-mas stuff and back to business.
So, Alleycat, you are saying that provided you keep the revs below 4 grand, the standard crank and rods will survive with the traditional mods you listed. Glad to hear. As you pointed out, the STR-8 doesn't even rev much past 4000 rpm. I can verify my 320 seems to lose power rapidly past 3600 rpm. Speaking of rod bolts, is there there a p/n from ARP or some other that would be a direct fit?

It's been a while since I last vsited the HAMB forum. I browsed thru the exhaustive information that Chub Chub pointed out (thanks a lot!), and it seems Ross now makes a performance piston, but I quess only for the 263?
I used replacement 030 pistons from Egge. They came with a Grant ring set, which makes use of one modern oil ring and one STR-8 type. I decided to discard the STR-8 type and use the modern type only, so I have nothing on the lower oil ring groove. So far so good. I also filled some of the dish, and coated the crown with a cermet coating (thermal barrier). This was done to raise compression and efficiency.

Okay, Alleycat, now we are getting into more exciting topics. What mods have you performed on the heads - chambers, ports, valves, springs, rockers? Again my main interest is in the large engine, but please shed your light on all engine sizes. I'm all ears, and so are all the others!
01-01-2006, 04:05 AM
didn't ross make them awhile ago? i remember calling them for my former 263 a few years ago........this thread is getting really good keep the great info comming.

viva la hamb :)
01-01-2006, 08:54 PM respect to the 320, you WANT to keep it under 4000. In my blurb above I was basic and brief, I could write pages and pages about this stuff... but the 320 is longer and taller and bigger. Mass in motion tends to remain in motion. The dynamics in that engine get outta hand fast, in the 248 and 263, which are more compact, it can be controled better. There is some supprisingly clever enginering in these engines and understanding whats really going on is key to the whole deal. Don't lay awake at night 'cause ya don't have a 4140 crank, work with whats there. Its good steel in there. All the old hot rodding tricks work, I use 'em because these engines respond to it. Of all the engines I've built the buick str8's are the most responsive. Virtually everything, you can feel in the seat of your pants. Forget "chevy think". So, all the stuff I relate here applies to all 3 engines, and its not "feel good" modifications. Gettin the power is not about doing 1 thing 100%, its about doing 100 things 1% and that 1%, 100%. These babys respond. Now, the reason your 320 flattens out at 3600 or so, is the top end. It just wont flow. The first thing you should do is get a buick duel carb set up. Every str8 should have 'em. The single carb runs the center rich and the ends lean, and the exhaust won't clear the cylinder. I have pulled more destroyed pistons out of str8's because of this than I can count.

A little more on pistons. I droped the 4th ring long ago and it works fine, but these engines badly need moderen pistons, ring placement and rings. The boys on the HAMB site are in the hunt but if the piston that fits their engine fits others...but 320's and 248's, no. Ive looked into custom pistons, the actual piston is not such a problem, the dome configuration is. Flat top pistons are best for flame travel but the chamber is WAY to big, and we have to live with it. Plus the little detail that if one of those pistons gets hurt, another must be made. This lead me to harley pistons. Everything is made for harleys. This piston gives everything ya want. Off the shelf. Plus 310 inches after its in there. But it only works on the 263. The drawback? Gotta make rods. The pin is higher and so the shorter 263 must be lenthened. I had access to a wire feed EDM, so I cut blanks out of 6061 aluminum and made my own. The harley piston has a hemi type dome on it, clears everything and gives 9:1 comp. Is it perfect? Probably not. But this baby makes power. I've also tried ceramic coating piston tops and it works when its fresh but as it gets covered up by carbon the effect diminishes. Plus the engine has messy combustion and a mirror polish everywhere seems to work the best. So, I did'nt do it in this engine, but I did teflon coat pistons and bearings, str8's have a lot of internal drag, it helps.

Ahhh...the head. What have I not done to the head? Morphidite thing. Bunch of plumbers cobbled this thing togather during break, I'm sure. That said, it can be made to work. Don't sweat that its siamesed, the inactive port acts as a plenum. Its all the square corners. The exhaust valve is ok. Intake needs to be bigger, I have a bolt in pt # for it. Gives 75% or so intake/exhaust ratio. I made my own valve guides, cut them on the top for PC teflon spring clamp seals, on the exhaust because the exhaust blows UP! the guide. Tried it in the intake, did'nt work so well, still got a lot of coke build up on back side. Flow loss! No good. So, I'm now trying umbrella type, just deflect it. Blunt conic on end of guide in port. 4 angle valve job, back cut valves, swirl polished. Highly polished exhaust. Drop the port floor about 100 thou, stoping about 1/2" carb side of the left/right corners at the end of port. About 7/8R on the corners, nicly rounded, and ramped up on the floor to giv a short side radius. Raise the roof about 100 thou all the way into the plenum, creating a nice rounded bowl shape at each end. Do not cut straight down to the seat, leave a rounded venturi. Thats the basics. Takes a few hours to do. However, this head will not work for spit with a stock intake/exhaust system. Factory duels, modified, at the minumn. I'm working on dual quads and stainless steel header, should really rock. I think this is enough for now. alleycat
01-03-2006, 03:01 PM
Alleycat, even if you are only touching the subject, each reply of yours requires some time to digest! Let's try to keep this thread alive and not get choked by taking too big of a chunk at a time...

When I was working on my 320 head, it was obvious why this behemoth doesn't make power - it cannot breathe! The BB Chevy exhaust valve was a direct fit for the intake valve, even the stem height and diameter being close enough. I used Manley Race Flow 1.88" diameter, slightly larger than original, swirl polish, necked-down stem, everything. I left the OE exhaust valve in place, only did the back-cut on it. I was able to remove LOTS of material from the bowls and guides, but I didn't touch the ports because at the time I was working on it, there was nobody who could have verified how thick the walls are and how to shape them. I did make an intake for dual 2-barrels, all ports equal-length, and headers. The torque is awesome. A friend with a '49 Roadie said he wouldn't have swapped an SBC, had he known how much potential lies there.

Now, your description of the port job is stretching the limits of my understanding of English. I understand avoiding removing excessive material where the port floor makes its turn to the valve, as the radius is very limited as is. But at the other end, are you saying that you made the ports slightly rectangular, leaving a short section of it round, so it still mates with a round intake manifold? Well, a picture would explain it.

I would like to stick with the head tricks for a few posts more, before jumping into other parts. Thanks and keep the info coming
01-03-2006, 03:13 PM
For those who havent's visited my site, I'm trying to post a picture of the intake here. Let's see how it works.
01-03-2006, 03:23 PM
And here's a picture showing the valves, the exhaust being the original and intake being a Manley stainless Race Flo unit. As a bonus, you get rid of that 5cc cavity on the combustion side of the OE intake valve, raising the compression a bit.
01-03-2006, 03:32 PM
That is AWESOME! I'm drooling!
01-04-2006, 09:10 PM
`Jyrki!!! Wow!!! You diffinatly are in the hunt! The photos are great. Photos are at this point beyond me. Describing porting without photos is hard. I'm very suprised that a BB chev valve works, don't know why I did'nt use it as I have several BB chev cars, and have worked over the heads on them as well. anyhow, as you look at the port from the intake side my port looks like a BB chev oval port heads intake, just smaller. The reason for this is that as air flow moves through the port it moves bottom to top as the valve moves up and down, with the short turn radius acting as a pivot point. Now, fortunatly, the port wall is thicker on the bottom and top,about .250-.280, so a .100 off the top&bottom is cool, but the sides are down to .210, going wider just kills velocity, which we want to keep,so leave the sides as is. The problem we'er trying to fix is that the port approches the valve at 90 degrees,realy hard to fix.

My first set of headers looked very much like yours, and I found that they are with out a doubt one of the biggest power gains on these engines. However, it means a unheated intake, which made my engine REALLY cranky and hard to live with. So, I went back to the factory duals which I ported out to match the oval ports. I have found that a 320 dual intake can be cut down and welded, giving a larger internal volume. this might work better yet. Enough for now. alleycat
jerry burger
01-05-2006, 09:57 AM
alleycat,i read with relish your talk on the straight eights.when you say 4100 rpm do you mean you shouldnt turn them past that point or they are incapable of it?i think in the lower gears they will turn around 5000 rpm if you just stand on it.and you are right this would soon tear them up.
01-05-2006, 01:48 PM
Alley cat, You are digging into some territory that hasn't been explored in years. I am glad to see that your 263 is coming alive.

I have a question for you. I have a 263 in my 53. I am running an Edmunds dual intake with two holley 94's. I am still using the stock single exhaust manifold so I am not getting the best benefit from running the dual intake. I recently aquired a stock dual intake from a 41 buick. It has two Carter carbs on it, using compound carberation. Front is the primary, back is the secondary. Would I benefit running the carter carbs or running the matched Holley 94's? Which carbs are you currently running. I plan on using the Edmunds intake, it has the plumbing for running the heater line through it to keep it warm.

01-07-2006, 12:44 PM
Never in my wildest dreams did I think that anybody would be intrested in the nut-case things that I've done with my buick...Anyhow, this rpm thing can get very involved very quickly, leading to a Lot of print...but I'll try. Will a str8 go 5 grand? Bone stock? Not a hope. Any engine, given a unlimited airflow potential, put a brick on it, will rev to destruction. Its the destruction aspect we'd like to avoid. How do we do this? Engine redesign or parts enhansement through sheer strengh of materials. The SBC boys have shown with out a doubt that given unlimited r&d time and $$$$$ any given engine can be pushed way beyond its design parameters. Where does that leave us? Jyrki's engine is a great example of what can be done reasonably, and he's in Finland! Yet, it starts to go "flat" at 3600. My 248's and 263's built in a same maner, would go about 3800. With my very latest head on a 263, I got about 4100. Not much of a gain. Wats goin' on? I did have the factory 2-2's on. Intake restriction? Jyrki dos'ent have that problem. Hmmmmm....Look at the bottom end, its huge. 320 rods weigh 2lb 2oz, and the size of the bearing journals!!! All the loads on the crank, friction, inertia,etc, increase with the square of speed. What I strongly suspect is that much beyond 38-900 the load on the crank is taking up more and more power just to drive it. The world famous "rock & hard spot". Aluminum rods take out a lot of weight, perpherial speed on the bearings due to their size can strip the babit off the shell and we don't have state of the art bearings....5000 rpm? Prehaps. Makes me nervous.
Fryguy, I've always used wcd carters, from 50 to about 54, as they were everywhere. Bigger on the v8's, I could mix & match, 4 bolt flange, bolts to about anything. Once set up, it's a "forget it" carb. I always ran them "straight up", as in, not progresive. The reason is, is that it's nearly impossiable to get even mixture distribution front to rear. The early carters will probably be to small, I'm runing biggest ones I could get. It likes it. I like the edmonds, but the internal volume is kinda screwy. Later. Alleycat
01-07-2006, 02:52 PM
To be honest, the fact that anybody is still messing with these motors is awesome! I thought that I was one of the few that thinks a Buick should have a Buick, etc, and I'm 28! We should all be thankful that there are like-minded people still floating around to talk to about these old things! I've loved Buick Eights since I was a little kid!
jerry burger
01-09-2006, 10:28 AM
what can be better than talking buick straight eights?im a young 71,and grew up teething on still as avid as when i was 21.i have a 41 century and a 37 special.i drive the 41 every chance i my literature is an british publication called (the motor).in it is buick road tests from 37 to 40 specials.they say the speeds given are an illustration a 38 special will do 58 to 59 mph in second by the clock.with a 28.5 tire height and 1.66 second and 4.4 axle the total ratio is 7304.this computes to 11.70+ mph for every 1000 rpm`s in second.58 mph divide 1170 = 4957 rpm.i dont condone this kind of use,and like alleycat says it is distructful.however with a .347 lift and the 1.35 to1 rrocker arm lift it would seem to underestimate the fabulous buick engines.i know they flatten out at 3800 rpm and up,but the dual carb 41 and 42 helped a lot.keep up the good work.
01-09-2006, 03:30 PM
Okay Alleycat, I think I understood your description of the port job. One more thing. The 320 exhaust port doesn't actually have a decent valve pocket, as the port roof is more like a straight slope directly from the valve seat to the port, instead of a radius. Is there enough wall thickness to experiment some serious pocket porting on the exhaust side?

Speaking of engine being "cranky" without the heat riser, I can verify your experience! Although with the stock single carb manifold AND headers combination, it ran smoothly, but I only got experience from driving it in and out of the garage, so it doesn't count.

Now, how about the valvetrain. I have been wondering if the stock rocker arm ratio might be 1.5:1, but jerry burger suggests 1.35:1. Is it the same within all engine sizes? Alleycat, have you found any roller tip rockers that might interchange? And is there anything you can do to the pushrods? They look sturdy but they are soooo long! Now we are getting hot - alleycat - are you willing to unveil the secrets of your cam specs? Is there a company who could make a completely new cam instead of a regrind? I wouldn't want to send my cam overseas, you see. A couple of years back, I read the California Bill's manual on hopping up the Chevy and GMC sixes, and the book touches the Buick STR8 as well. It seems like Howards and Isky were making several grinds to the STR8, which were called "2/3 grind" and alike, which tells nothing to me (or to most others on this forum I'm sure). With the right specs, I could have my cam reground locally. Or I already did, but to stock specs, sans increasing the lift a bit, since they always have to decrease the base circle anyway. The #7 cam lobes were totally flattened out, probably due to an oiling problem. Anyway, this thread is like pouring some gasoline to the fire!
01-12-2006, 09:48 PM
Face it jyrki, you've created a monster here. A regular frankenstein, with bolts.

I'm not sure of the rocker arm ratio, never measured it. Something I gotta do. As for roller tips, the sheer lenth of the arm eliminates anything made. I've thought about making some, but with a seat spring pressure of 52 to 76 lbs the effort would be for "coolness". Now the pushrods are another thing. They are 1024 steel, and when made were flat stock, rolled and welded lenthwise, then the ends pressed on. They flex and are soft as butter, or nearly. I've bent plenty, and found plenty bent in engines I took apart. So, I went nown to my favorite hot rod aircraft place and got some 4130 .375 tubing and made my own pushrods. That worked. Then I made some out of aluminum, tapering up thicker in the center. I think if I do it again I'll make a die and hydroform them. Lighter still. In any case this fixes the pushrod problem.

Camshafts. We have a little problem here. Once, long ago and far away, new cams were made. If any are still around, I've no idea where. So, I've thought about welding somthing up but the cam is way long, it could end up looking like a pretzel. I've thought about making a roller cam, it could fix a coupla things...I have seen more than a few flat cams, wrecked lifters, lifters not rotating....Why? Turns out that on a lot of engines, prehaps all, the cam does not line up with the lifter bores. Not good. Is it the cam? The lifter bores? Not sure. The only fix so far is to shove the cam as far back in the block as it takes to get the lobes off center to the rear, the lifters will then most likely, rotate. Cam&lifters are not cheep, ya want to check this. Then a spacer must be made for between the cam and gear, this can be .100-.150 thick, these lifters have a big base circle and sometimes it has to go way back. Cam grinds, hmmmm, problem here too...Compression. A cam only adds something like 10-15% to the power game, increased duration pushes the power curve higher in the rpm range. Due to the flow potential of the head, we don't have a power gain over 4000. The meat of the power curve is 2000-3000 or so. As soon as the duration gets "out of the window" we start to loose compression, by the valves being open too long at low rpm. With 7.5 comp stock, unless its been milled heavly, and even then, comp goes down fast, so does power. I think we're limited to about 215-220 duration. It may take a thoughtful cam grinder, but what we need is as much cam as possiable with little compression loss. I've not found it yet. What works on a sbc does'ent on a buick.

Exhaust porting. They are not bad. The guide suport is way to big. The walls are about .250 thick. Make the floor wider & flater, a "D" port, basicly Shape the guide boss by sliming it side to side, and front to rear by blunting the front and tapering the rear, kinda like a flat aircraft wing. Don't get really crazy here, as the exhaust can out flow the intake and about 75% of intake is what we're shooting for. Be careful of the end ports, you can get water in the upper corner if not careful, just round & smooth. With headers or factory duals its hard to improve.
01-13-2006, 12:10 PM
Alleycat, you have definitely done your homework on the STR-8! I can believe someone making his own pushrods or even connection rods, but fabbing up a cam is just too much!
Your reasoning against increasing cam duration makes perfect sense to me. Even if we didn't count the lost compression, moving the power peak rpm past 4000 would be waste of effort. I agree, the majority of power is found by mitigating the flow restrictions - the head and the manifolds. But we COULD benefit from increasing the valve lift and/or the opening rate. This could be done by regrinding the cam or by increasing the rocker arm ratio.
Since you mentioned the valve spring pressures, I got the impression that you are using nearly stock spring pressures, am I correct? While using the BBC valves, I would encourage using BBC retainers, locks, and springs as well. I'm not sure, but I think even the stock BBC springs are rated higher that those of Buick.

Speaking of the lifters not rotating, none of them rotated when I took apart my 320. I thought it was because they were so coked up with carbon sludge. It took me a great while to even get them out of the bore! But, now we know the actual reason.

Would you prefer milling the block deck or the head or both, and how much would be safe? And how about the head gasket - composite or copper? During my initial build, I used composite to be on the safe side (leakage-wise), but the next time I'm going to open it up, I will use the thin copper gasket that I have in stock. I was stupid enough not to have the block deck surface milled when it was being overbored. The surface from the factory looks pretty rough to be sealed with a copper gasket.
01-15-2006, 01:37 PM
Hmmm..I did'nt think making my own cam was all that "out there", just stick a hunk of metal in the lathe and remove everything that dos'ent belong there. Now as for changing the rocker ratio, this could present a problem, in that increasing the ratio to something like 1.6 or 1.7 would mean relocating the rocker arm shaft. This could be difficult. However we have a "advantage" with the buick lifters, they are 1". SBC are .825? or so. Back in the good old days, befor roller cams were not so totaly reliable, big base lifters alowed a more aggressive ramp on the cam, simulating roller cam dynamics to a point. SBC guys made lifters with a big base, a "mushroom" lifter, so they could exploit this effect. A cam grinder that says " O yeah, I remember how to do that", and can, would be cool. But my bet is it will take more meat on the core to do it. I think with more research a really advantagous cam could be made.

As for valve springs, I am using the stock stuff now but I have a new inner spring that will give me about 125 closed pressure for the new engine. Yes, more springs are avaiable for chevys, and more pressure to be sure. But!! I rockwelled the block, its not hard, about 8-10R. So are the seats. What beats the seats out is a lot of spring pressure and sustained rpm. And then theres the lifters. The hydraulics were never designed to resist a lot of pressure, if you have solids, no problem. So, I think 100-125 lbs should be more than good.

Speaking of seats. The cumbustion dynamics are not good. The engine generates a LOT of carbon. It coats everything in there. It curls up and flakes off. Some goes out the ehaust and some gets traped on the seat. Carbon is harder than the iron. The process pounds the exhaust seat and valve to death. It will look like its been shot peened. It happens fast. Some of this junk goes down past the piston, it scores the wall, wrecks the ring seal and eventualy breaks the rings and destroys the piston. A total polish job on all parts in the chamber and a really hot ignition goes a long way toward fixing this.

I've milled both the deck and the head, both to gain the compresson and to fix some problems. I found that I then had valve geometery problems. Now that I've come up with the Harley piston solution I have any comp ratio at hand that I want, so I dont mill except to clean things up. I like a copper gasket because of the heat transfer charistics. The only drain for the head is at the back of the block, and this engine I'm building things could get hot, so I am also drilling some extra holes in the deck to mix things around and cool things better. alleycat
01-17-2006, 01:57 PM
You certainly gave us something to think about and something to watch for. I think a lead substitute additive is a must. At least Red Line's additive contains detergents as well, helping to keep things clean.
Now that you have mentioned ignition, what kind of improvements have you found there? I'm using a Pertronics Ignitor inside the stock distributor, and a Pertronics coil, solid core aftermarket wires and don't-remember-which-plugs, and it seems to work fine. But I'm pretty sure there's a lot to play with the advance curve and static advance.
01-19-2006, 09:49 PM
Actualy, the ignition was somthing I kinda ignored for a long time. Mostly because all the hot ignition stuff I was around was on SBC, which did!!...absolutly nothing! So I thought why bother on my buick, it runs fine. As gas got progressivly worse it ran less fine. So, one day I did a experiment. I hooked two 6-to 12 volt voltage doublers up to a jacobs compu-ignition and went for a drive. HOLY COW!! The thing took off like a scalded dog!! It's ripping down the freeway and I'm thinking "wow, is it my imagination or what? This can't be!" Well, after a few miles the system set itself on fire and burned out, and I had to tow it back home. I've tried several systems over the years, one thing for sure, str8's like a good ignition. It's money well spent. Hands down, the best ignition I've found is the MSD unit, the 6A. It really is a multiple spark at low rpm, exactly where the str8 needs it and it will start several flame fronts in the chamber. Things happen slowly in there and this works reeeally well. Cool thing is, I have it runing through the stock distributor, which if set up properly works excelent. The msd unit can be hid, and it all looks stock. I've also machined up a HEI to fit. Its kinda big, so it takes some fitting but the advantages of really good caps, big wires, and other hot rod parts that ya can just buy make it a serious contender.

Now as for timing curves and such, bone stock, I found that I could crank in a lot of advance, fast. This can cost power, as the pressure is starting to build as the piston is still moving up. What this was telling me was cumbustion was bad. So, what ya really want is as much pressure as posiable as close to top as possiable. With a highly polished chamber and piston, seriously good ignition things get much better. About 10deg inital, 34 total, all in by 1700-1800, and you absolutly want the vacume advance. When the gas hits the carb, it'll start, right now!! alleycat
01-21-2006, 08:47 PM
Where can I get a dual carb and intake, who makes them or sells, them I need carbs and the intake for my 40 special.

01-22-2006, 09:31 AM
Alleycat, Can you run an MSD box with the 6 volt system?
01-22-2006, 09:50 PM
Tom, as for finding carbs, buick used the wcd 2bbl down draft for years. From the early 40's to 56. They are all of virtualy the same design, with the small ones early on and the bigger ones 54 to 56 or so. Look down the carb from the top, right betweenthe bores will be a fractional number, from 1 1/16 to 1 3/16. Earlys will also have 3 bolt bolt-up, lates are 4 bolt. Just grab a bunch at swap meets or wherever, all the parts interchange. If your engine is pretty much stock, the smaller will work best, built up, it'll handle the biggest easly. Don't run 'em progressive, both straight-up. Manifolds show up on ebay fairly often, but I'll just bet some of these buick guys could scare you one up also. When you get it, clean up the casting inside the exhaust manifolds, just where it turns off the head. Buick left plenty of metal in there and it needs the room, and polish the surface, exhaust likes shiney.

Yea arron, minor oversight, msd has a theshhold voltage.It will run on 6v but it is a bear to start as the 6v system draws a ton of amps when starting and thus pulls the volts down below minimum. Thats one reason I went to 12v. alleycat
01-26-2006, 03:00 PM
Alleycat, I'm sure you have experimented a lot with different intakes and carbs. Could you give us some guidelines for fabricating an intake? What to look for? In some previous post you already mentioned about running the dual 2-barrels "straight up". In that case, will a single cylinder see 2 or 4 barrels in total? You also mentioned omitting the heat riser making it "hard to live with". What else to avoid?
I have seen some ancient Edmunds multi-carb intakes, which don't look too good from a design-point of view. The plenum is overly large. Looks hot but would kill your idle quality and drivability for sure.

Which carbs to use if you want some tunability yet want to look classic or period-correct, or what to use if you can choose any modern carb (oh well, carbs aren't that modern anymore). This subject may be endless but let's give it a try.
01-27-2006, 01:52 PM
Well, Jyrki, the intake manifold is a intresting problem. I'm about 99.9% sure that everybody who has tryed to do anything with the intake has got it wrong, including me. The str8 is basicly two 4 cylinder engines back to back, which makes manifolding it properly, really hard. I'm sure that good manifold would make major power. The factory duals are very good, remarkably good considering when they were made, which makes me think that the boys in buicks engine r&d had something very different in mind than the engines that we got. The edmunds and other multi carb systems, like that 5-carb stewart(?) are going in the wrong direction. The engine, when properly built, like we've been talking about, will handle a lot more carb than 1 little 2bbl.

I've tryed everything with carter wcd 2bbl's. A very tuneable carb, looks correct, takes stock (looking) air cleaners, and when its all under the hood, most would bet it came factory that way. Not! The 263 I'm now building will take way more than 2bbl's can provide. 4bbl's are the only solution.

I've machined up finned side covers, finned valve covers and a host of other billet bits, so a intake did'nt seem that difficult. Hmmm...well now. Prehaps I was a bit optomistic. A 180 degree manifold seems to be the answer here, running a wcfb carter, looks period, and I had a few, including a very early matched 2-4bbl set. I want dual quads. A single 4bbl 180 would be easer to design and possiably work as good perhaps better but for major impact...well...

The manifold designs I came up with looked very much like the factory duals. This was machineable, weld the parts togather, presto!, dual quad intake. Cool, but not totaly there. The cross over tubes between the carbs are not there for mixture distribution but to smooth out pulsing in the system. This can be used as a advantage. When the intake valve closes a pressure wave is sent back up the intake, if it can be made to arrive in front of the next opening valve it will push the mixture into the cylinder. I happened to pull out a old dual quad manifold for a oldsmobile, the answer.!!! Like, in the last 2 days! I can not machine this design, it must be cast. My effort on the dual quad manifold was , I guess, practice. Back to the drawing board.

So what is needed in a manifold here is: carb heat, the engine will be no fun without it. Small plenum. No square corners. Smallish runners,1" X 1 1/4" apx. with no taper. Runners that start larger and get smaller act like a manifold with a big plenum and short runners. The opposite of what we need. Balance tubes between plenums placed in such a way that when the pulse is returning back up the runner it is routed to the next to fill cylinder and not the base of the carb. Long runners. That should get us 98% fo the way there. alleycat
01-27-2006, 03:43 PM
Large plenums- been there, didn't work, they're small now. No square corners - done here. Tapered runners - gotcha! This is my worst pitfall so far. Balance tube between runners - most interesting. I'd like to see proper applications.

I knew this thread was like opening Pandora's box - all hell broke loose! More knowledge more pain and frustration. And there's no end to this!

Anyone with a digital camera, please I'm begging you! Get yourself to Alleycat's place and take pics of his designs! Better yet, send the guys at SA-Design to make a how-to-hotrod-STR-8 book out of all the material in Alleycat's ring binder!
01-30-2006, 11:31 AM
Yup! Pandora's box, kicked the lid off and out of the ballpark!! I am thinking about geting a digital type camera, ( I have a really nice slr 35mm...) but they seem kinda odd to me, and then there's all that electronicle stuff to get it in here....I just figgured out how to make reliable paragraphs. Now that SA design stuff, I'm not sure me and my notebook are quite ready for prime time...But! I'm working on doing a tec sort of manual for building a str8. Trouble is I'm recreating some of the stuff I did and inventing new stuff at the same time. I did'nt take photos, make drawings, etc, early on, and now!!!, I'm totaly back to square one with intakes, however, the new design is waaaay good. Anybody who wants to build a really good str8 or a all out motor is going to want my book. Then there's that self recrimination thing, reading the book or just this site, then, "I coulda, shoulda, diffinatly woulda had I known", ooooo well. Happens to me all the time.

Something else is dawning on me...Perhaps all these parts that I come up with after a few hours of machine time are somewhat beyond most...Welllll.....something more to think about...alleycat
01-31-2006, 02:01 AM
Take your time with the book - it'll be worth waiting for!
What do you think about the oiling system? Some engines had an oil filter to the valvetrain, some had nothing. The pump feeds the oil directly to the mains, and there's no way to filter it. The pump pickup is quite clever, as it kinda floats and follows the oil level in the pan, and stays away from the sludge in the bottom of the pan.

My 1946 320 cid didn't have any filter from the factory. I made up one, but at the same time I restricted an oil line that was squirting oil to the distributor gear. It was an outside pipeline from the main gallery to the distributor mounting boss. I simply pinched the pipe with pliers. I don't think any of the engines w/filter even had this oil line. I think it's crucial to have a good supply of oil to the valvetrain, as upon start, it will take some time for the oil to reach the rearmost rockers, and the rockers feed the lifters thru the pushrods. So the cam lobes will operate a moment without fresh oil. Well, there's is a chance that the lobes will get a splash from the crank shedding the oil all over the crankcase.

Have you made any modifications to the oiling system?
The factory recommends a 20 weight oil, which seems a bit thin to me. What weight and type of oil have you been using?
Straight Eight
01-31-2006, 02:06 PM
THAT WAS A FACTORY MODIFICATION ON THE 46'S. THEY WERE WEARING OUT THE GEAR. It really belongs on there. I can send you the modification specs for it that Buick put out if you want em. Check out for article and photos.:thumbsup:

New thought

Has anyone come up with a cure for chatter? Like a brace between the engine block and the rear tranny cross member?
01-31-2006, 02:31 PM
Thanks for setting me straight! And be welcome to join our discussion.
I'm wondering if you have worked for Buick in the past? You seem to know a lot about the factory specs.

In what driving conditions does that chatter occur?
Straight Eight
01-31-2006, 04:03 PM
:shifter: Any attempt to accelerate from a dead stop when the clutch is slipped with the engine rpms higher than necessary to start the car . Starting up a hill from a dead stop, parking on an incline. I found an after market kit that bolts between the bell housing and the rear tranny cross member. This has helped more than, new motor mounts, new tranny mounts,o'haul the mains for slop, and rebuilt the tranny to eliminate slop. I kinda think the mount under the bell housing is the one that is not doing its job, because the aftermarket brace has really helped the situation. Oh I just remembered, when cold for a mile or two it had no tendency to chatter, only when warmed up.

How about the factory bulletin for your oil line, would you like me to scan copy? My knowledge just comes from extreme interest in the Buick Eight, and keeping them on the road. I have read the manuals from cover to cover, and own a 47 56C.

Straight Eight
01-31-2006, 08:46 PM
Sure enuff, sneeking a peak under the hood of the Y job revealed what looked like huge dual carburetors :shifter:
02-01-2006, 01:48 AM
Thanks for making my day, Cliff! And I thought the culprit for the chatter was my clutch! I never renewed the pressure plate, as it looked good, only replaced the disc. Yes, it chatters from a dead stop, and my 2.73 rear gear makes it even worse. I do have new motor mounts up front, but since I converted to a Super-T10 tranny, I couldn't use the stock transmission mount. Instead, I now have two smaller mounts, from a Volvo, one on each side of the bellhousing. It would be nice to see a picture of that brace. It's hard to imagine how it works. Maybe they changed the front motor mounts in 1948 just for this very reason?

Yes I would like you to scan the specs, absolutely!
02-01-2006, 11:27 PM
Well now, page 4!!! Cool!. Yes, I've done some things to the oil system. As Cliff says, you don't want to restrict the oil line to the distributor and it feeds little in terms of overall volume. As for putting plenty of oil on the top end, don't sweat it. The sbc guys have been restricting the top ends for years and gettin away with it, we can too. The cam is lubed by splash, what runs down and hits the cam is mostly luck. The bearings are fed off the mains. The hydraulic lifters are fed by oil forced down the pushrods, kinda reversed. But, the buick 8 never was intended to have hydraulics, just solids. Oil splashing around works fine for solids. Even the 263 was not designed for hydraulics,because!, the 263 was ready for production by about 41, WW2 put it off. Hydrulics were not seen as reliable. Why? NO bloomin oil filter!! It still did'nt get one in the late 40's when buick was doing the v8 and they knew all about oil filters, what were they thinking!! It was a easy change!I can't think of a way to add one to filter the oil befor it hits the mains & rods. Now the canester filter that filters the oil to the valvetrain will, eeeventualy, filter it all but its a little late for the bearings. You could put one on, any filter is better than none! I did'nt like the way the oil line went into the end of the rocker shaft, and had to find its way to the other end, someday. So, I put the shaft support with the connecting hole in the center of the assembly, drilled a through hole, ran a longer line, presto! oil supply is now equi-distant from each end. I also made a spacer to make the oil pump gear case deeper, cut a gear in half, stacked one on each gear, and upped the volume by half again. However, I was running clearances at the top, thats when I discovered that buicks like to be at the factory minimum. 20 wt should work, how buick thought they could get away with it 50-60 years ago with the quality of oil eludes me. I use delo 400, 30wt for now.

Chatter, Hmmm, never had the problem but I run a dynaflow in my buick.

Yes, the Y-job had a 320 and it got probably the first dual carb setup made. Mr Earl had some pull at buick. It got the big wcd's. alleycat
chub chub
02-01-2006, 11:40 PM
This "chatter" talk should probably be its' own thread since it seems to be more common than I thought. I have the same problem with my '52 but I haven't even gotten around to thinking about that can of worms yet.
Straight Eight
02-02-2006, 05:46 PM
Jyrki, The front mount takes the torque twist to the side. The two Volvo mounts you used at the rear of the engine should absorb the front to rear action,not side to side, the rear mount handles up and down on the back of the tranny. I sent photos from the manual so you could see how they are made, and what they look like.

The forty eight changed the mounts to further isolate the vibration and also to help control the chatter of the previous set up.

I know the Dyna Flow Roadmaster in 48 first starting out in reverse felt like engine torque was being applied in jerks, and once started moving would smooth out.

02-15-2006, 01:21 AM
Alleycat, what have you come up with headers so far? I understood that you have experimented with tubular headers, but weren't happy with them, as they omitted the carb heat riser. So are you now back to factory manifolds?
02-16-2006, 11:53 PM
hello i just found this forum and its just what i have been looking for. I have been into the straight 8,s since the 50,s. Have semi stock 39 century sedan, with '41 dual carb intake and a street cam in the engine. I see in the forum that there is a lotta interest in the straight 8,s. I am going to mill the head and make up new pushrods with moly tubing. I have a 54 packard 4 barrel manifold i want to install, and am now pondering the adapting of a overdrive ford top loader transmission, using my column shift. i am new at writing in a forum but looking forward to it
02-17-2006, 02:12 AM
Welcome to the forum, 39CENT! Yes, there's a lot of interesting info on this forum, and you seem to like fabricating parts, which is the way to go since there aren't many performance parts available for the STR-8.
Does the Packard manifold match the port spacing of a Buick?
02-17-2006, 01:30 PM
the Packard 4 bbl manifold is very close to the Buicks port spacing, and total length, you will have to do a little grinding, welding, here and there to line up 2 of the ports [maybe 1/8" off]I havnt done mine yet but its very straight forward to do. It is basicly like the Buick, except it has bends instead of 90 deg. angles like the Buick. Oh, the other thing is that it is backwards from the, Buick as it mounts on the opposite side of the Packard engine and tilts the carb the wrong way, so it will need a spacer there.I keep wanting it because it almost looks stock, like a phantom Buick racing part. Actually you can make your own manifolds probably better than looking for a Packard . i just found mine in a friends parts pile.
02-17-2006, 02:05 PM
well i am new to all this forum stuff so i will throw my 2 'CENTS' in. I have been interested in these engines since i was a teen and went to see the night, drags at the old Colton Ca. dragstrip in 1955. hmm 50 years ago? first race i saw was a 50 Merc pull up to the line [late model stock]in the F stock class. next a big dirty green old coupe pulls up, and i recognize it as the same year Buick my uncle had, a 39' buick. Gads wotta barge! Well the Merc jumped first and was leading, but the 39 was gathering steam and when he hit second gear it just leaped ahead. And then that big old buick just kept walking away, i cudnt beleive it, Mec,s were fast, how could that old Bu do that !! He mustv been cheating! Well he was, he had a special rearend in it. 4.11 gears help if u have all that torq, along with the top end those Buicks have. and probably the .125 off the head along with a bored out carb. oh well it looked stock, and the Merc probably did the same.
02-17-2006, 03:38 PM
Well maybe i should enter some interesting hints and info ive picked up from old Buick nuts. One was from a guy who ran Buick str 8 in a 32 Ford roadster, he hit 170 mph at Bonneville. [a roadster is as streamlined as a large brick at those speeds]. It had 1050 cfm holley carb. on a home made intake, & headers, filled head, big block chevy exh valves, and wildly ported intake and exhaust. balanced it, used flat top pistons,[ive heard u can use 235 over size chevrolet pistons with top shaved.] He also removed the pinch bolts and welded the top ends of his rods, and shot peened them. I dont know about the cams since ive heard about almost everyone uses a diff cam. I talked to Don Montgomery who started out racing Buicks, and he used .090 over 228 GMC pistons, but they have huge pop ups, he was runnig alcohol and 14 to 1 compression. If u can find out what the GMC boys are doing, you can do a lot of the same things. GMC and Buick have same style ports and combustion chambers. GMC,s are running 200mph on the dry lakes. they are mostly 4x4 bore/stroke. siamese ports seem to do ok as some the old siamesed ports.are still running on the lakes. Well some of this is way beyond what most of us want to do but it shows what a Buick can do.
02-17-2006, 09:29 PM
Hey Jyrki! Looks like we've picked up another enthoozest!! I'v never thought about GMC engines and possiable parts interchange. 39cent being in the socal area you've got a advantage, racing is rear around and a lot of the guys that did it to the old stuff are still around!! Cool! I, on the other hand, was in the sticks. One drag strip and I went plenty but never saw anything except the regular stuff. It gave me plenty of ideas on how to make my buick faster. I started inventing. 40 years later I'm still at it. The packard manifold, thats good!! Never woulda thunk....However, I am getting close to making my own manifolds and a few other things, I spent most of last week going to foundrys, mighty intresting.....

Exhaust systems! Other than the ignition system #1 for power gains, headers are #2. I cobbled up a header for my buick when I started doing them for bikes and race cars. It was'ent all that pretty, but did it make the power! The drawback was no heat to the carb. Made the car horrriable to live with. Then I put on the dual carbs and I made some water boxes to bolt on the bottom of the heat riser bolt up. This worked. Heat to the carbs, header, this baby rocked!! However, it leaked. The boxes really need to be cast. That way they could be really snuged up. So, I decided to try the factory manifolds, these are a good design. I ported them out and sent them to Extrude Hone for a polish out. They work almost as good as headers, with some prep, and they are trouble free. This is what is curently on my 50 now. A curious thing. I put dual 2.25 exhaust all the way out. Wanted that "look" from the back. Lost power. Went to single 2.25, powers back. Don't quite get it. Perhaps dual 2"? The next header will be for the 263. It will be 1.5 for about 12-14" steping up to 1.625, 180 degree merge collectors, 40" or so long and all out of stainless steel. These'll make some power. alleycat

PS. Hey fryguy! I'm having a heck of a time making that "personal message" thing work! No chance! 320 cam won't go into a 263 or 248. 320 is all by itself.
02-18-2006, 05:32 AM
Thanks Alleycat. I did get your message. I wasn't sure if the roadmaster ever changed engines.

You say you tried running dual 2 1.2" exhaust and you lost power? This was on the hopped up 248? I am getting ready to run the dual exhaust out on my 263 and I was struggling to decide which size exhaust to use. Maybe I should try 2 1/4 or should I start at dual 2"?

02-18-2006, 06:40 PM
Hey fryguy! You got the whole message! Cool! Was'ent sure....The exhaust pipe thing... This has me somewhat preplexed. I've built many exhausts for race and street cars and every time a inline engine comes up, what I think should work, would bet money on, dos'ent. V8's, I get it bang on, or really close. I've also talked with other guys around the country that have had the same expierence, all by accident. I'm thinking that it has to do with the rpm range of inline engines, firing order/# of cylinders and displacement. The last incident of this was on a chev 292, a healthy engine, built up, headers and dual 2 1/4 all the way out. I'd of bet money this would be perfect. Nope, single 2 1/4 pulled the bottom end way up and hurt nothing else. So, as much as I and everyone else would like to see big honkin pipes, they don't seem to work. A cool experiment would be to bend up 4 systems, 1 3/4 to 2 1/2 and put em on, run em and see what will do what. Now, I don't know exactly what you have for exhaust manifolds, headers would be great, factory duals good, single.....well.. I think dual 2" would be all the engine will need. Thats what I think I'm going to put on my 263, and its BUILT to the max. alleycat
02-18-2006, 11:52 PM
there was an article somewhere that i have to find, on installing insert bearings in the old babbit rods , using Buick 455 inserts. you just melt out the babbit and resize the rod so the later inserts will fit. [Terril Machine i think does that]They are narrower than the str 8 rod bearings but they are harder and will take more stress. another thing i have to find. the one thing ive been looking for was welding up the combustion chamber for a quench area and running flat top pistons like the 37 buicks. its been done but i havnt really found the info on that kinda mod. they used to do that way bak. the head is another story. the ports are small but they shud be ok for the rpms that it will be running, need to make em flow good mainly, they dont need to be real big.I think the GMC guys make the back wall of the siamese port flow better and probly use a 'lump' on the floor to make it flow and turn down the 'hole' to the intake valve. you have to get all the torq out of the engine under 5000 rpm. the guy that ran that 32 roadster at Bonnieville said he pulled the maincaps on a str 8 he had when he went over 6200 r,s. I think thats the limit gg. thats when the crank starts to act like a snake. ohh yeh, and that guy has an overhead cam head he welded up using 2 aluminum, R22 toyota heads, [they have close to the same bolt pattern too]. he has done it but didnt finish it. [he,s a certified welder]Has to figure out how to run the cam chain. I think it can be done. this sounds crazy but i do know that the toyota head has close to the same bore and bolt hole spacing as the Buick. wudnt that be a trick set up?? ok gotta go , find more info.
02-19-2006, 04:18 PM
this thread is getting crazy!
On the page you can sort pistons by diameter. Like a candy store! I just went to hunt for Chevy 235 str-6 pistons. Being 3,5625" in diameter, with a .125" overbore you could make it fit the 320 Buick and make it a 343. But I don't see any reason to shave the top off. The Chevy piston is a flattop and has a compression height of 2.06", while the Buick piston is something like 2.36". I didn't calculate it (it's 1 am here right now and I wanna go to bed soon), but I don't think that the increased diameter would add enough compression to compensate for the .3" decrease in compression height. But, back in those days, there must have been many types of pistons available for the Chevy 235, and this example is just what I found on the Silvolite offering. Then again, it doesn't matter if the piston is not flush with the deck surface, as the Buick is an open chamber design without any squish band (quench area). For the same reason, the Buick turbulator design works better than a flattop. Weld up the chamber to make some squish / quench, combined with a flattop piston, and you have a winner!

I also found a 1954-64 Ford 223/256 piston that features a 3.625 bore and a 1.857 compr. height.
02-19-2006, 04:23 PM
39CENT, did you edit your previous post with some notes on the buildup of the all-out engine? I recall I saw something like that yesterday, or have I been dreaming?
02-19-2006, 05:43 PM
yes i ,m new at this so bear with me, i sent an answer to one of the str-8 guys, I think he was askin about cams i,ll have to go back and check, It was some notes i took in a conversation with Jim Earl longtime ago. They were some of the mods that he and his Dad did when they were racing str 8s. There were a bunch of Buick racers in the Los Angeles, area, and they were turning close to 100 mph at the drags with str8 Buicks! Buicks were pretty fast wih a couple of mods. All you needed back then was a milled head and a Special rear end in a Century [which bolte right in] and you would be able to beat most stock cars on the street. The Century was one of the first Muscle cars back in the day. I remmber they were still a few racing them when i entered the scene. The stick shift Roadmasters like yours took the place of the Centuries after the war as they had dropped the name then. Oh and about the chevy pistons, yes the reference to shaving the top must have been about the hi compression pistons that i think you still can get, [forged pistons] Jahns pistons, and Arias possibly.
02-20-2006, 05:59 PM
Jyrki, this thread is getting just "out there", the entertainment value can't be beat!!

I checked out all my new and old piston calalogs and came to the conclusion that these guys that 39cent is talking about are diffinatly running 320's. It looks like the chev or gmc piston could work, but!!, the rod lenth problem crops up, it would have to be made even longer to compensate for the shorter comp height on these pistons. Like 8.5 inches!! Wow!. I've never sectioned a 320 block but buick stuck with the same casting thickness in all engines, so, I'll just bet the wall is about .350 to .375, which means that a .240-.250 bore out would be feasable. I've not crunched the numbers but I'll bet it would be close to 400 inches! What originaly lead me to this huge a bore out is the 320 piston, I had a new set of thompson pistons and I wanted to put them in my 248. Not a chanch for the 248 but the 263, yeah! And, the rod could be shortened. So I hack sawed the small end off, took out a bit and welded it back up. It worked. However, from a high performance standpoint, everything was WRONG. The problem with the gmc or chev pistons is that they are a old school design, with a even longer rod. And a flatop piston will loose power in the buick. Why? The buick "turbulator" piston really dos'ent turbulate much. What it really does do is increase the surface area of the piston considerably. Torque is porportional to surface area. This piston is accidently very good in this respect. If, as 39cent says, welding up the chamber on the back side to fit the piston close, like .040, could be done, that would diffinatly make turbulance. It would be great. To get around all these problems is why I went with the harley piston. I do have to make rods but I made them fit a mopar 360 rod bearing, and totaly modern pistons are available as well as rings for the harley, I now have a totaly up to date reciprocating package, and the weight reduction!! I am shootin for a solid 300 hp and I don't know how much torque. If something like this could be done for the 320, it would be a monster. This is so cool. alleycat
02-21-2006, 02:35 PM
Alleycat, in regards to your exhaust size question. I will be running the 41-42 Buick stock split exhaust. I will have to modify the the left side motor mount to get the dual to work. Best case scenario would be to bend up 4 sets of different sized exhaust systems. But I don't have access to a Mandrel bender and its not something that would be cost effective on me. I'd like to get nearest the first time, worst case change it twice. Somewhere between 1 3/4 and 2 1/4 diameters? I'm not worried about running the big diameter exhausts out the back. Any size is fine with me as along its increases flow and not hinders it. You can always put big chrome exhaust tips on the back to make it look huge, LOL

02-21-2006, 08:12 PM
Hey fryguy! You've got the next best exhaust manifolds. As I've mentioned, I'm running the same on my 248, I just ported out the top of the ports and sent them to Extrude-Hone in california, for a directional polish and they are only just shy of headers. I went 2.5 all the way out. Too big. Prehaps did'nt cost any power but did'nt make any either. So, I made a nice merge collector about 36" downstream, into single 2.25 and that pulled in the bottom end power great. If you are worth a darn with a gas welder, you can get mandrell bends and fab it up yourself. Once past the **** mandrell bends look cool but add little, so just have a exhaust shop bend it up. Alleycat
02-21-2006, 08:39 PM
these are notes i got from Jim Earl on strt 8 mods. here are notes i made in a conversation with Jim Earl, who,s father Jarvis Earl was running a Buick straight 8 dragster @140 mph in the 50,s this is not precise info, just some of the things that i wrote down quickly. might give U some ideas.

this is old info that they did on thier 38 Century coupe.
kenney harmon cams [1-415-472-1414] k.60=.269Lift, k.80 =.422 lift .296 dur. k-90 =.388 L [this is old info]. chevy sm blk valves [undercut manley,s], cut valve guides. port an fill intake. [D port]? buick 322 valve springs, main caps beefed[hardenedstraps], turbulator Buick pistons+ mill head .180 = 9.0 comp. ,420 Lift 268 duration cam? copper coat headgaskt, chk piston to head clear. redrilled wilcap HE 427 ford steel flywheel, beefed centry clutch [40#springs], .pistons 060? chev 235/261 piston machine top down.??? shot peen rods, 1.60 rocker arm ratio? 55,56 packard valves?,howards cams F4F - .275L .250 dur, crane cams inq. comp cams? isky #55 cam,distributer advance 12 initial 32 full @ 2500. 4.44 rr gears with 27.5 in tall tires bring rpms up ez steady to 3000 rpm on line. then let out clutch smoothly, 1.60 rocker arm ratio?
02-21-2006, 09:09 PM
the main thing i do is look at what the straight six guys are doing. I think most of the modifications would generally be the same. The cam grinders are coming out with much better cam profiles etc. The 248/263 8,s should work really well, i think they could make more horse power for thier size than the 320 inchers. The 320,s are just torq monsters and the rpms are a limlting factor. Hey what about using the small journal rods from the 248,s and offset grind a 263 crank for longer stroke, [more torq] or destroke it for more rpm,s [more HP]. Now we have good electronic ignitions that are really great, and you can feel the improvements. The really big improvement would be using a electronic fuel injection unit from a late model car. Also using 4 or 5 speed overdrive transmissions, stick or auto, gearing is very important.I think that the quickest way to get performance is to stick a blower on them. A Blower would make all the power instantly from to the bottom to the top end of its rpm range. It can be used on a completely stock engine and do all that you really would want in power. I really like just having that straight 8 under the hood because they can really move those big monsters down the road, and they are still a fairly modern engine, trouble free and will last a long time.
02-23-2006, 11:31 AM
Hmmm, my buddy just called me and offered me an Eaton...
Well, maybe not. But in the future, I'm going to try EFI for sure - tired of fiddling with the AAV-26's

Speaking of the straight-6 guys, can you give us a brief of what they are doing?

I found on the web that Venolia offers pistons for the "Wayne 12-port" Chevy six. I would quess these are high-compression pistons?

Have you guys read the California Bill's Chevy GMC (and Buick) Speed Manual, the 1954 edition? Most of the information is outdated, yet it's truly fascinating. For instance, Bill recommends against using new lifters with a new performance cam, but instead insists on using old lifters which are "glazed with carbon" as they will outwear new lifters! Quite contrary to today's belief.

It seems like a manufacturer called BARKER made some hi-lift rockers for these engines.
02-24-2006, 01:34 PM
The biggest thing about these old Buick strt 8s is they are an 'INLINE' engine. Thats where they differ from others. Inlines have a different power band,they are designed to make lo end 'TORQ'. The straight 8 [also 4s and 6s] gives the smooth torq to use higher gears for greater hiway speeds So you have to get all thier 'power', [both torq and HP] below 4000 rpm. All the normal hop up stuff, cubes, compression, cam,breathing,timing etc will give added power, and this is where all the fun stuff is, making more power for the fun of it and feeling of improving performance, and hopefully without spending a lotta money. A BLOWER will give you all this on a STOCK ENGINE without all those mods. A blower, [or turbo], is the short cut to having your cake and eating it too, from the bottom end, all the way to the top, thats where inlines shine. The next thing we can do is 'GEAR' that big bomb. Proper gearing is very important for these heavyweights. So i can give you some names of books etc that will help in modifying all engines and specifically inlines. First is 'Chevrolet Inline 6 Cylinder' power manual by Leo Santucci, and any of the books by David Vizard, also check out books on supercharging, go to bookstores and check the racks in the automotive sections where u can read some of the books to find out if they have what you want. Pay attention to all modifications for good low end torq, almost all engine mods are generally applicable to inlines.
02-24-2006, 01:52 PM
If anyone wants to be a doityouselfer, read Jyrki,s site. he gave me many ideas and inspirations, he tackles it all. And if anybody wants to read about a home built turbo installation on an old car look up this site, its a real blast!!!
02-24-2006, 02:01 PM
Ca. Bills hop up book is still basically good info and in general applies to all inlines, and yes the oldtimers reused lifters, i think that there were a lotta wrong or bad parts out there, and if lifters were used then they would probly be ok to continue using them, i have a set of used solid lifters on my regrind HERBERT cam.
02-24-2006, 08:51 PM
Wow, you(Alleycat) say around 3 feet back you went back to a single using a Y-collector. Very interesting. Are you using an open rear or are you using some form of the stock torque tube?

As for gearing. Is there a way to manipulate that using other torque tube Buicks rears or do we have to change to an open rear to gain that option. I am sure Buick used different rear ratios on their torques tube drive shafts. Whats the consensus. I know the open rear is the best option but what other options are there?

02-25-2006, 05:49 PM
Fryguy, believe it or don't, the "optimum" primary tube lenth for the str8 is 40 to 44 inches or more!! And, the intake at around 24inches! Where did I get this? Well, there are some tech books dealing with intake& exhaust along with books on thermodydnamics and physics which I got into when I went to the "big school" and when you crunch the numbers this is what you get. However, sometimes the book and the real world don't quite agree. I found that the pipes can vary by 10" and actually work better, it broadens the power band, the intake can be fooled with, but 24 or more is it. Which, if a person looks at that howard 6 carb set up, can see that its all wrong for the str8. It is still a booger to get all that plubbing under the hood, which puts the collector just about under the front seat. I've spent days under there fabbing....

I'm still running the torque tube rear but I've changed gears around. The stick cars have 4.11, this works for the 1/4 mile. The autos up to 51 came with about 3.6, plus or minus a tooth or so, this is a good all around gear. However, if you start getting some power out of the engine, it will start to sound "short". 51 or later mostly came with 3.23, this works great! with that gear and some power, these road locomotives really step out. They are bolt in's. The open rear would give you more options but it's a major job to get it under there and then there's the trans, getting the driveshaft to plug in.....

Here we go....I like my dynaflow. (I can here it now, HAW-HAW-HAW...) Have I left my dyna alone?...Are polar bears afraid of the water? ( Haw!, not!!)I"ve done major mods to it. 20 years ago 18 or so mpg was ok. I'm thinking that we will see $5.00 gal gas sooner than we'll ever see $1.25 again...I like to drive my car. What we need is a overdrive. I think i've got the solution in my shop. Jyrki will love! The volvo overdrive is a laycock "bolt in". I think with a front and rear flat plate adaptor, resplining input and putput shaft, bada-bing, overdrive! The rear gear ratio is now moot. Going down the freeway at around 70 the engine will be turning around 14 1500 rpm (I have a sw tack), with a 3.6, around 1800, tire size figgures in here, so we're "ballparkin" here. Anybody up for 25-26 mpg? With my 263 under the hood I'll pull any pass at any speed. So much for the gear problem. alleycat
02-26-2006, 06:33 AM
I've heard some Pontiac and Olds transmission tailhousings bolt right up to the Buick manual trans, providing an open driveline. Rear gears swap but the 1954-55 don't fit the older axle, unless you swap the whole third member.

Volvo? HERETIC! Yes the Volvo M46 gearbox has a Laycock electric overdrive, commonly seen in the British makes such as Jaguar.

Bendtsen's offer a trans adapter for a TH-350/700 automatic, for about $700, including a new gear reduction starter motor. See

At the time I built mine, nothing was available from the aftermarket. So I machined my bellhousing to accept a B-W Super T-10. With a Muncie, you don't even have to swap the clutch plate, as it comes with a 10-spline input shaft.

A third-gen Camaro/Firebird rear is a fairly easy swap to any chassis with an X-frame.
02-26-2006, 03:16 PM
I don't see where in any of the advertisements or installation instructions or in miss. parts where they include My Mini-Starter for the NailHeads in the pricing or even offer it for sale. If you call & talk to Bob he may mention My Mini-Starter as an option that's stand alone. I have been referred to others by Bob.
I haven't as of yet, but I must send Bob an e-mail to thank him for doing such.

Tom Telesco
02-26-2006, 10:44 PM
the gearing is a big deal because its not that good for todays driving. The engines have torq but Buicks are heavy! My century has 3.90 gears in the rear and even with the big tires i have it still feels like its in second gear on the hiway. The 3.60 was an option for my century but not available anymore, and a 3.23 RR from a mid 50,s Buick sounds good, but then first gear is a little tall for the big series. The torq tube rears can be fitted complete using the whole later rear end by chopping it to the right length and just fitting up the torq ball/u joint. Yes the Olds, and Pontiac small series, are basically the same trans as the Buick, with open drive. The big series Olds V8s used a buick transmission up into the late 60,s, and it is open drive, I have one. the oldtimers used to use a 37, 38, floorshift Buick case with the Olds tailshaft for open drive, or they just bolted them into 54, up thru maybe even 1960? However you can make a later model open drive trans fit the buick bellhousing and go open drive. Jyrki did in his 46. I have a ford toploader overdrive trans, from a later model ford van. It has a lo first gear, and the a kinda tall second then 1 to 1 in 3rd, and overdrive in 4th. Its kinda wierd gear ratios but I,m thinking about it. I also found found a 4 speed column shift from an old Mercedes that might work off of my column. Hmmm maybe i,m getting too far out now??
02-27-2006, 06:17 PM
Yeah!! The gearing is a big deal! When my special was stock and had rather a few miles on it, the 3.9's worked ok. But, as I got more and more power out of it, it felt "short". At that time around here, buicks were in every wrecking yard in huge amounts. I went out and tore into rearends and got every ratio there was. Tryed them all out. The 3.23 was the best for covering the ground at speed. However, if the engine is not making any power, the baby is howling at the moon. Now I'm thinking "overdrive". My 248 may not make enough power to pull it. However I've just found out something. While trying to make sense out what "39" is relating about the drag race engines specs (I don't know how they made it even run), I took a drive over to a cam regrinding outfit, Delta Cams, Tacoma WA., and had a talk with them about str8 cams. This is a area that I'm not to up to speed on. Turns out I'm not far off. The cam I had Comp Cams grind for me is little better than stock. So, for all practal purposes, all the power increase in my 248 is from ignition, the dual carbs, and head porting, the cam contributed zip!!. Seems that delta has been there befor and they know about the bigger base lifter and that a more "advantagous" ramp can be done, and the rocker arm ratio being not over1.5 if that. They also confirmed that much over 212-214 duration in the str8 is a waste of time. They have two grinds for the str8's, one for the smaller/stockish type engine and one for bigger engine or well built up. I took em two cams, gonna try em both!! Perhaps my 248 WILL pull a overdrive!!! You guys want cams? These guys will grind them for ya! No big mystery!!! Two day turnaround! Can't be beat! Alleycat
02-28-2006, 08:17 AM
Alleycat, I definitely would like to try a different grind for the cam. I have the 264 with no big engine mods and dual carbs. I don't have an extra cam laying around to send ya. Do you have any extra 263 cams? How much did they quote you for the cam grind?

03-01-2006, 10:35 AM
Yeah, fryguy, I do have a few engines kicking around and they have cams in em, but I gotta dig them out. I just got the cams back from the grinder and do they look nice, and one of them was kinda not so great looking. There are two grinds, one nicely "warmed up" and the other "hoter". I 'll have the exact specs in a day or two. Either cam would work for you as you have the bigger engine, the bigger grind will give more mid range, like in the 2000 rpm area. The grind per cam is $108, a better deal can't be found. I'm going to hunt around for a few extra cam cores, just to have, as the wrecking yards for a long ways around here, all buick parts are totaly gone, never woulda thought....alleycat
03-01-2006, 11:58 AM
when cores cannot be found anymore, you'll find new ones from EGGE. I don't know if they manufacture them or outsource them, but they are available.

Regarding mileage, the best I could run with my Roadmaster last summer was 20 mpg. It's quite an accomplishment for 1930's technology in a heavy car. Yet, with our gas prices being at $5.45 per gallon, it's barely tolerable :(
03-01-2006, 01:45 PM
Hi all!

Camshafts are mentioned in Egge pages, core 150$ and grinding it 73$.... Would they grind it different specs if asked?

Maybe cam profiles could follow same route as the Ford 300cid straight six, since thay both are straight and torque engines.

Are there many differences between '49 and '52 big eights, what makes the 20hp difference. Distributor is different as is timing, compression also. Egge lists different product number for their cams.

Great thread you've got here!
03-02-2006, 07:43 AM
I wish I could find a few buick motors to have on stock. I have been looking and looking. $108 is a great price for the cam grind. I am definitely in as long as I can find a core. How much would you charge me for a core? I may have a guy that may be able to send me an extra, I'll ask him as well. Let me know Alleycat. What part of the country are you from?

chub chub
03-02-2006, 02:29 PM
I saw this reground 248 crankshaft on ebay today, so I thought I'd share it with you. 4596228154QQrdZ1
Also saw this straight 8 engine/trans combo 61206QQrdZ1
03-02-2006, 02:42 PM
Yeah, I saw those too. $500 for the reground cam seems pretty high to me. I don't think that will work for my 263 motor.

The motor seems to be a decent deal as its a fresh rebuild. It costs that much just for the rebuild.

I have a line on a guy I bought a few things from. He has the whole motor available. I am going to try and get the head and cam.

03-02-2006, 04:51 PM
Cam cores are now getting hard to find. You diffinatly don't want to toss this stuff into the scrap. The annoying thing is, that up to less than a year ago I could have got a dozen with little trouble, different story now. Can't throw anything away, soon as you do, two days later its needed. Problem with Egge is that only stock grinds are available, and 150 bucks a core? I'm going to put a little more effort in to digging up a few spares and perhaps have a few cams ground at one shot. The cool thing is, is that two grinds are available above stock.

Yeah, that gas milage thing, kinda figgured that you were getting whacked good in your area, jyrki, "barely tolerable" huh....sounds scarey. I want to keep driving my car and I'm trying to keep it realistic, and we are, as you said, dealing with 1930's technology. I'm going to have a real good idea as to how realistic my ideas are in a few months, when I get the 248 back into my '50.
03-05-2006, 02:07 AM
Alleycat, could you try to find out the lift & duration specs for the two grinds from Delta Cams?
I assume the specs are rather similar for both the small and large engine. What I'm thinking about is having my 320 cam reground locally to the correct specs, as sending it overseas back and forth would be costly and risky.
03-09-2006, 12:36 AM
Jyrki, the buick piston height, is that for a 1937 piston? or is it the later popup piston hght? that would account for it being higher than the chevy. Whatever it is, in order for it to be within reasonable price, a piston would have to be found that had the right compression height, so it would be even with the block at TDC, and close piston pin size, of course also close to the same bore size, preferably where u could get an oversize for more cubic inches. Oh well just use oversz 37' pistons. and weld up the combustion chamber like the OHV cadillacs and oldsmobiles would work good.The oldtimers were running around 340 to 356 cubic inches bored out. Not much you can do with the rods, not a big selection in over 8 inch rods out there. The rods can be welded by the bolt and normalized, shot peened etc. but the main thing is just don,t rev them too hi. There is a larger size crankshaft dampener I have one but its the only one ive ever seen. The ports on the head can be raised by filling in the top of the ports on the outside of the head, and then grinding or milling them higher. That would make a better angle into the head, for that important flow thats needed, flow is more important than size on these heads. the stock heads dont flow, its like they were designed to keep the engine from revving!
03-09-2006, 01:50 AM
Hi, I would like to know the specifications for the connecting rods on the straight 8 engines. I would like to know the rod journal diameters, wrist pin diameters, lenght of the rods, and the distance from top of piston to wrist pin location. This is for the 248, 263, and the 320 engines. thanks for any information anyone can pass along.
03-09-2006, 01:50 PM
39CENT, the compression height I gave in an earlier message is a measure I took from a stock 1946 320 piston (I kept one). It has the "turbulator" dome. The total height from the center of wrist pin to top of dome is 2.843" according to shop manual, and measuring verified that. But the distance from pin center to piston crown is 60 mm which equals 2.362 inches.
The Chevy I-6 piston falls short, and does not come flush with the deck.

For those who might not know, if the piston crown does not come flush with the block deck surface, there's no point in welding the chamber, as threre will be no squish action. Some people also talk about quench when they mean squish. The idea is to create a tight clearance between the piston top (flattop piston) and the "closed" area of the combustion chamber, at the top dead center. As the piston approaches TDC, the mixture in this tight area is forced to a high speed, creating turbulence, which in turn increases flame speed = more power, better efficiency, more tolerance for compression ratio, less spark advance needed, less susceptible to knock. In theory, the best chamber shape would be the hemi-spherical one together with a flattop piston, just like the ones seen in 2-stroke engines. It can be done on a 4-stroke engine too, as we know, but leads to many compromises and expensive designs in port and valvetrain configuration.

The quench area actually means that the surface area, in that portion of the chamber, is too great in relation to the volume of that same area, cooling off the mixture so it won't ignite at all. The sole purpose of this area is to create turbulence, and this turbulence is usually directed towards the spark plug.

Welding the chambers sounds like a lot of work. I wonder if it was possible to weld a piece of mild steel in the chamber to lessen the weld work and the shaping effort thereafter?
03-09-2006, 02:10 PM
One more thing. The whole idea of adapting I-6 Chevy pistons, came from the fact that no high-performance pistons were ever made for the Buick I-8's, while there are, or at least were, high-performance slugs available for the Chevy. It's not only the increased displacement or compression ratio we are looking for, but a better piston design. I would like to find a forged or hypereutectic cast piston with a modern design, utilizing modern piston rings close to the crown, cam ground, offset pin location, etc.
03-10-2006, 12:08 AM
Has any body thought about having the deck surfaced. Like if someone were to find pistons that will fit the wrist pins and the piston is just .125" below the top of the block?::bana:
03-10-2006, 12:13 AM
I'm thinking about using a buick straight 8 in an old tractor for tractor pull.I thought that it would be neat!!. building the engine with big pistons and 9:1 compression ratio. Lots of torqe:shield:
03-10-2006, 11:16 PM
Does anybody know the lenght of the connecting rods for the straight 8 engines. like on the 248,263, and the 320 engines?:confused:
03-10-2006, 11:17 PM
I think they only deck the block just enough to get it square with the crankshaft, and thats usually not very much. You dont want to mill the block much because it needs to be thick enough to keep the bores from warping when torqing the head. Running a straight 8 in a tractor would be interesting There are some guys running big straight 6,s and even running 2 of them coupled together! And they do PULL!
03-11-2006, 12:21 AM
Jyrki, they made hi-po pistons in the past, forged, in various comp. ratios. I have a set of JE pistons in my 39 block, but mine were made long ago. And from from some of the advertisements ive seen they still make custom pistons. I talked to Don Montgomery who built and raced Buick I-8.s at the drags n, dry lakes , he used .090 over GMC pistons, and they wiil work on a Buick but the piston needs a bushing for the smaller Buick pin. I have a few of those pistons and they are the same dimensions as the Buick except for the bore, and have a much taller popup and very HEAVY! Don was running alcohol for fuel so the very hi compression would work. He,s the one who had that 6 carb manifold. yes the new hypereutectic piston would be the best way to go. And yes welding up a head is a lot of work. it was done a lot in the old days, i never heard if they welded iron in there, it was mostly they would grind into the water jacket and build up the quench area with weld, and then finish grind the combustion chamber to spec. I think that for everyday use just milling the head, a cam, and mild porting is the best way to go. I get carried away with dreams of a better breathing head, but for what they are, they do pretty good. I think your Buick does really well considering you gave your friend a good race against his modern chevy engined Buick. With the right gearing you might have won!
03-15-2006, 11:46 AM
Got some cam specs from Delta, the mild cam is a 252 duration with .420 lift. This will net out @ .050 to .206-.206 or about there. The hoter cam; 260 duration with .440 lift, this should net out @ .212-.212 @.050. However!! This is not the whole story! This is a grind that we see a lot in chevys, etc. There not the same. When I went to delta, I discused the lifter not rotating problem with them. We also talked about the buick lifter being 1" in diameter, which means that we can indeed get a more aggressive ramp profile on the lobe, way more than smaller liftered engines, like a sbc, the chevy guys go to a lot of trouble to do this trick and still are not close. No chevy type profiles. We also put about 2 1/2 to 3 degrees taper on the lobes is order to get the lifters more inclined to rotate. The lifters are oriented in pairs closer each other front to rear. That means that the taper on the lobes must face each other in pairs, not the same direction down the lenth of the cam. Delta has a profileing machine but the str8 cam is too long for it and they must hold it by hand in order to profile it. They did'nt do this for me as they thought that I was a one time only. They did'nt realize that guys half the world away wanted to know. So, I'm going to take them one or two cams and we'll really nail it down.

con rod lenth.
248: c.c.-7.625
263: c.c.-7.375
320: c.c.-8.250

Hey! "39", are these guys you talk about, that raced str8's, the guy that welded two toyota heads togather, still around? Could you actually call "em on the phone and find out what they are thinking now? And what that head is doing? The only reason those guys used all that old stuff 40 odd years ago...., is , moderen stuff had'ent been invented yet! Reinventing the wheel may, perhaps, yeld no more power than it did then, so,.....on to the biggest problem of the str8's....

Rods & Pistons!! Venola makes a very nice rod, the "superod" for big sixes. Its quite long, over 7 inches. It could, just possiably, be streched to just barely make it into the 263. Just. 248-320, not a chanch. This is why I've made my own rods. Twice. I did it in order to get the piston design I wanted into the engine. Its the only way. The comp distance is just too great. Getting the reciprocating weight off the crank is the only way to make these engines "live long & prosper", if you get my drift. There are pistons available that fill all our demands. I'll say it again. Harley-Davidson. Pistons made for H-D's have been made in every configuration known to man, and then some. Small changes to piston design cost little or nothing once your past the actual design, like leaving out the valve cutouts, etc. In order to make these pistons work a longer rod is required. Bummer. This dos'ent hurt in the 263. The others, well...Bad things start to happen at rpm's. In the case of the 320, there is, just possiably, for the "no guts, no glory" group, a way. Pic your piston, probably a hemi dome, forged, pin as low as possiable, harley disign, a piston that won't cost $200+ a slug. Calculate rod lenth, probably about 7 3/4". Cut the top of the deck off. (!!!!!!) Just under the head bolt threads. Cut the outside water jacket down, leaving the clinders standing tall. Bore out the deck out to drop over the clinders. Mark off the standing extra. Cut it off and bevel the outside of the top of the clinder in. Bevel out the deck. Weld it all back togather. Shorter block. Requiring , thus, shorter rods. Deck & bore the block, chase a few threads, and your ready to go! This will require a very good welder. Oliverbuick, you just happen to have just such a guy down in
Smoky Point, by the handle of "Iron Mike". Have fun! alleycat
03-15-2006, 08:58 PM
Alleycat, i found the answer to makin that 263 blow the doors off the 320,s. and it will work fine on a stock engine

Here's a link to one that is turbo charged that was recently on ebay. dZViewItem ( dZViewItem)
03-16-2006, 04:30 PM
There are also a couple of nice photos of a 4-71 supercharged 1950 Buick on the Inliners International site (scroll to bottom): (

Webrodder also has a couple of links for their Buick "Fireball" buildup that might be of interest to other people:

Part 8 - Using the Bendtsen's trans adapter behind the straight eight

Part 9 - Generator to alternator conversion made easy

03-16-2006, 05:59 PM
Hey guys....If you read my posts of a while back, (we'er up to post # 87,!!!!) you will find that I supercarged my buick 248 long ago, Now at the time I had a switzer-cummings unit that I used, which is more like a turbo than anything else, and I did gear it up a little, but its still not like a roots type. I could'nt afford a roots but I also did'nt have a machine shop either so it just was'ent feasable at the time. The switzer unit has some nice things going for it, like low load at low speeds, but once its cranked up...boost is boost....I ran it around for a while around town, back 'en forth to school, etc, Then I figgured that its time ti find out what it'll really do, a run up to the cabin ought to do it!! There was a 40 odd mile spot with no lights, traffic, etc. Holy...Crow!!! I know what the Duesenberg, Auburn crowd mean when they say it starts to "whine" and gets up on the boost curve, baby flys...It was running a little "funny" when I rolled into the drive at the cabin, it was running real funny when I made it back home. After the teardown I found 1,as in one, good piston. Thats when I found that pistons for str8's are crap. The engine is only as good as the weakest link. Supercharging works, but you better have good parts in there.

My 248 will most probably eat a 320. My 263/310 without a doubt, positivly, will. No sweat.
03-16-2006, 11:44 PM
What about using tractor pistons. some tractor engines have 10" rods? I'm going to do some research on tractor piston specs and let you what i find. My criteria for pistons is compression hieght, pin diameter. connecting rod being centered in piston, and diameter. do any of you buick guys know if the 320 can take a 4" bore?:coo:
03-25-2006, 09:01 PM
say anyone out there know how later model hydromatic 3 spd or OD works out on a straight 8?
04-15-2006, 11:15 AM
I'm currently working on adapting a laycock j-type overdrive unit out of a 80's volvo to my dynaflow. I've also tryed every rear end ratio that buick had, and for just rollin' down the freeway, 3.23's the engine likes best. These engines are torque monsters, hp is just a byproduct/afterthought, so anytime the engine is built up, torque values go up way faster than hp. So, it's my thinking that a overdrive that gives a final ratio of 2.40-2.70, which would be about 1400-1500 rpm at 65-70 mph, or thereabouts, and the engine would be pulling right into the meat of the powerband, it should work great! Now, a bone stock 248, prehaps, may not have enough grunt to pull a 2.40 final, but with a 3.5, or so, with a 25% overdrive, this would give a 2.70, or so, should be fine. And the mileage?...Will be way over 20...alleycat
04-17-2006, 10:54 AM
Alleycat, good info, with torq tube drives, need all the help we can get. I am tossing around some ideas for my 39 century [3.90 ratio], with the ball joint mounted in the middle of the x memeber it has the honor of being the ******* child in buick torq tube rear drives. This makes some things easier,and some more difficult. I need to get taller gears for freeway driving, and your experience with later rear ends with the 3.23 ratios sounds good. i think it would adapt to my 39 ok. however I have a ford top loader ovr/drv trans from a ford van, its a full syncro trans with 4th gear o/d, and it looks to be adaptable inplace of the the buick trans, but it might entail using an opendrive, and then hooking up a column shift!! [ early Mercedes]Or I could use a jeep 176 T [which is a ford top loader, and uses ford gears] and have floor shift like the early buicks!
04-17-2006, 10:59 PM
Ha! I should of figgured that with a handle like "39cent" that you have a 1939 century, and dynaflows are very rare in 39, sure, your car has a stick trans. You may be better off than you think. I think, now don't run to the bank with this, but, I think that the rear end gears and case, that is, " the pumpkin" is basicly the same from sometime in the 30's to '55. The actual driveshaft is retained with a pin, the torque tube bolt-up is the same, as is the housing, axel splines, the same. Other than cosmetic differences and maybe a added rib or two, I think this would go right in. 3.23's are the most common rear from 52 on. This alone will make a profound difference in your car.

Making a ford toploader work probably could be done, but there may be a easer way. GM's trans were very much the same for years, and there were overdrives on some of these trans. Why buick never got the option I'll never know....The SAE boys set up spline specifications for a given shaft diamiter, GM pretty much stayed with them. You might be able to get a GM overdrive and nearly bolt it on. But!!, Gear Vendors uses a laycock overdrive, like I'm using, and since the GM trans stayed very nearly the same for a long time, they may have a coupler and a adaptor that will just bolt up, however it has a open tailshaft. There's a u-joint of some type in that torque ball, with a shorty driveshaft, a u'joint input switch around, you're on the road. Gear Vendors dos'ent give away these units but it might save a LOT of time. In my case, with a dynaflow....well...I must be very creative. alleycat
04-20-2006, 07:18 AM
Muncie, Super T-10, and T5 will bolt on to the stock clutch housing with some modifications. You need to grind the hole in the housing larger, in order to fit the larger front bearing of the later gearboxes. Then you need to drill and tap a couple of new holes to match the bolt pattern. If you are using a Muncie, that's all you need - it has a 10-spline input shaft like your Buick does. Borg-Warners come with a different spline count, thus requiring a new clutch disc to match. The input shaft diameter and depth are a direct match. The speedo cable is available at any parts counter, since they were the same until they became electronic. Shifter location may give you some work. With a Super T-10 in a 1946 Roadmaster, the shifter came too far back, so I notched the bench seat a little.:shifter:

Oh well, you do need an open driveline to go with the new trans. Third-generation Camaros and Firebirds have a torque arm type of rear axle, and can be installed to the X-frame quite easily
04-20-2006, 07:22 AM
Alleycat, if there's anything about building a performance I-8, that I forgot to ask, but you would like to share, I'm all ears!

How's your latest engine coming together?
04-21-2006, 09:59 AM
Jyrki, you would not believe the ideas that I have rattling around in my head, for internal combustion engines in general and str8s. I most likely will never live long enough to try em all. Stuff I tossed out here, juuuuust scratchin the surface.....

The transmission thing, three (3!!!) to choose from!!!! I kinda thought that very little had really changed with stick trans. Did you try em all? This is great, really great, almost like shootin fish in a barrel. The only "problem" remaining is the torque tube, if a person is not too hot on converting. I took a look at my muncies and t-10's and the end of the trans is plenty thick for this: Machine up a flange copying the torque tube bolt up flange. Press it onto the end of the trans. Tig it in place. Convert the CV joint, which requires oil, to a u-joint, which takes grease. Adjust the drive shaft and torque tube to correct lenth, any driveline shop can do this in about a day, and bolt it all up. I'll just bet that gear vendors has a overdrive for t-10's or muncies. This would be such a cool set up.....

Sending the pistons for the 248 off to Swain Tech Coating in New York, for ceramic dome coating and teflon skirt coating. Str8's have a very high piston speed, cutting piston friction is a very good thing. I'm changing the porting in the head and I'm going to flow bench it with stock, what I've got, and what it'll be. Should be back in by june. 263/310 is getting worked on somewhat slower, but the car it's going in is'ent even remotly ready. No rush. I may toss it in my 50 when it's ready, just to test it. It's going to be a full 100hp + over the 248, probably just gotta try it...alleycat
04-21-2006, 11:29 AM
I measured both Muncie and ST-10, and the ST-10 was far more affordable at the time. From what I know, a T-5 is similar but only features a canted bolt pattern.

Thermal barriers are most effective in a low-compression engine. I coated the piston crown, combution chamber & valves. This usualluy nets a 5% increase in power, but also a much greater improvement in mileage.

For reducing friction, I also coated the skirts, but nowadays there's a much better, revolutionary substance called RVS. It may not be available in the US yet. It creates a hard, very slick metallic-ceramic (ferro-silicate) layer on all ferrous (iron, mild steel) surfaces that are subject to friction. This is no bullshit, I have seen this work and are using it in all of my engines. I have also seen a block in a machine shop, run with RVS, on which the cylinder walls were "glazed" with this substance, being almost too hard to be honed off. This is also the reason why new engines should be allowed to run in properly to bed in the piston rings before the treatment. See

Keep us updated on your progress. :laugh_4:
04-29-2006, 07:39 PM
Actually, I was'nt going to use any coatings in my 248. I've expieremented a little with coatings and had mixed results. Dome coating that was no longer there when the engine is opened up, with not that much run time. Teflon skirt coating that is gone with 15 min of run time...But I think I'm finding the proper prep and clearance to make this stuff work, along with the technology just improving with time. I'm certain that there's merret in the stuff, I just want it to work over the long term. So, I'm going to try again with the 248. I want to give the pistons the best chanch of surviving as possiable. I have relatives in california, I'd like to drive my buick down there...and back!!!alleycat
05-01-2006, 01:13 AM
Hi, I just ran accross this sight and am thrilled to see this thread! I have been a fan of straight-8 performance for years and I'm happy to find some others that are too. I've always been a Buick fan and also a fan of dry lakes racing. I went to Bonneville in '91 so I could worship at the one true altar of speed. A trip all hard core motorheads should make at least once in their life! You will see more ***** out, kick *** vintage speed parts being used to their fullest potential in one week than you will see in a lifetime anywhere else. I went to learn about the old engines, straight 8's, Jimmy 6's, flathead fords etc. I met a really cool guy named Bob Opperman who ran a straight 8 in a lakester. I will post the pics of his machine as soon as I figure out how. He ran a bored out 320 with side draft webbers, 180 degree headers, vertex mag, dry sump oiling and a whole bunch of other mods. I know he was turning 5500 rpm and going in the 200mph range. I don't know if Bob is still kicking or not. I corresponded with him for about a year after my trip. He was trying a long rod big dome combo the next year. He said he had to grind all hell out of the block in the area where the cyls. meet the crank case and that the ultra big domes absolutly killed his flame travel inside the combustion chamber, he had to add a ton of timing to get it to run. I'll post some more on it when I get the pictures up. Anyway when I got back from the lakes I hunted up a nice 320 core and was going to build my own lakes racer. I did a ton of research, talked to everybody I could get ahold of in the aftermaket industry that messes with the old stuff. But as too many know life got in the way. If people are interested I'll post some of what I learned. I've got most of a 320 for sale also.
05-01-2006, 01:44 PM
Be welcome, and please share with us all your knowledge!
05-01-2006, 01:51 PM
Alleycat, regarding coatings, I have had success with Tech Line coatings, CBC2 cermet thermal barrier on piston crown & chamber. Coated the SBC pistons on my Cobra back in 1997, and years later, when I swapped new heads, the coating was intact (yet covered with soot)
05-01-2006, 03:43 PM
i hope this thread keeps going it has been an interesting read i have the factory dual carb intake an twin exhaust manifolds on my 53 263 am going to try an run 94 holley carbs i have on it unless someone knows of better carbs , ignition is stock distributor with 12volt pertronix ignitor conversion an im going to try the msd al 6 box i have laying about sounds like a good idea have a th400 out of a pick up for a transmission using bentdsens adapter hope it runs good :thumbsup:
05-01-2006, 08:17 PM
hey guys, If you wanna see a real old staight8 dragster check out 'CHUCK HAMANN' on the net! He campaigned a Buick dragster for many years, taking on all comers in his class. And doing it well i must say.
05-05-2006, 04:59 AM
Hi guys, I just wanted to let everyone know that I tracked down the guy I met at B'ville in '91 throught the SCTA-BNI website and sent him an email. I hope to hear from him soon. I also saw that the record that he set in '91 for vintage engined lakesters was still standing at 176 mph. I thought I recalled it as being higher, but like all good stories, we tend to remember things a bit better or faster than they really were. I think that this guy will be a wealth of straight 8 speed info. I also tried to upload the pictures that I took but the file size is to big so I have to figure out how to shrink them or something. I'm trying to wrangle a teenage computer geek to show me how. To alleycat; I found your post of the smaller straight 8's "running circles around the 320's" very interesting. I believe you but I'm trying to figure out why? I don't think that internal friction is the main culprit. I know that the cranks are real heavy. Trust me I've moved mine around the shop plenty of times! and that internal component weight is very important to engine response and acceleration, but I would think that power output would still be tied to engine size. Do you think that the breathing ability of the head is playing a major role in this or is it a lack of any good aftermarket parts or modern upgraded modifications?
05-07-2006, 08:00 AM

You can email me the documents if you wish, I can redo them and post 'em for you.

05-07-2006, 01:07 PM
Hi there bigrivy!! Welcome to the site. By all means find that lakester guy, I would like to hear about how he got around or solved the problems inherent in the str8. As to why my "small blocks" will eat up a 320 is really a matter of engine dynamics. The bore/stroke ratio of the 263 with its shorter rod, bigger bore is not too bad considering the 248 which is bad and the 320 which is worse yet. The internal friction component of each engine is determined by how much surface area the engine has and it increases to the square of speed, as does the reciprocating weight. Then there is the piston speed. At low rpm's it's not such a big deal, in these engines it gets outa hand quickly. And then there's the thickness of the piston rings, and there's four (4)!! of em, and the bearing size!!! Bigger is not better! A bearing that is 1/16" bigger, all things remaining equal, will cost a engine 20 hp. These engines have bearings 1/4 to 1/2" bigger than engines of comparable size. This is partly a problem of crank lenth, bearing number and location. A cranks strenth has a lot to do with journal overlap, there's not much overlap in any of the cranks, and the 320 is longer by 4 or so inches and has to live with the same 5 mains! We have limited options. The 248 due to a "goofy" bore spacing will only go so far befor insurmountable problems. So, it's not a candidate for a all out effort. 250 hp or so is it. The 263 is a very different engine. It is a way more moderen engine. It still has huge bearings but it is a shorter engine and with a up to date piston/ring package, aluminum rods, harmonic damper with a aluminum hub, the bearings can be cut down, the crank itself can loose a LOT of weight and best of all...this engine can be bored out at least .250. Displacement inches don't have anything to do with power, torque is a function of surface area, hp is a function of engine speed. With these changes the 263 now has has a very serious leg up making lots of both. Then there's the head, but that will have to be for later. alleycat
05-08-2006, 08:29 PM
Fryguy: your personal settings are such that I can't send you any kind of email. Let me know what your email is or email me and I'll send you the pictures to post.:confused:
05-09-2006, 01:07 PM
Actually, upon further thought, some actual numbers might go a long way in explaining why the 263 has more potiental than a 320.

1. bore/stroke ratio. This is a compairison of the stroke lenth divided into the bore size. It shows first off what the potiental rpm range of a engine possiably might be. A. 320: .80
B. 248: .75
C. 263: .77
These are not good ratios. A good ratio would be something like 1.2-3 and up. SBC have ratios like this. There is no way to get these ratios up by much.

Piston speed. This is a average of the distance and rate the piston is travelling. As the piston is approaching tdc and bdc it is slowing and acclerating respectivly. If plotted on a graph this would be a bell curve.
320: 2 x 4.312 x 2000rpm/12= 1437 fpm 2x4.312x5000rpm/12=3594fpm

SBC 302: 2x3.00x2000rpm/12=1000fpm, 2x3.00x5000rpm/12=2500fpm

263: 2x 4.125 x 2000rpm/12=1375 fpm, 2x4.125x5000rpm/12=3437fpm

The chevy is good speed for the size. A lot of engines now have speeds lots lower. Piston speed has a direct relationship to internal friction. None of the str8's are good, but the 263 is lower. Major destroking and boring can change this problem somewhat. You will notice that at 2000rpm the speed is not really very bad, it gets really out of shape at higher rpm's, fast!

Inertial load. This could be a really involved calculation, so I'm keeping it simple. This number showes just what the crank has to handle. We'll just do the weight of the rod.
320 rod: 2lb 2oz, making it easy, 2lb. 2lb x (2000x2000)rpm=8000lb
2lb x (5000x5000)rpm=50,000. 8cyl x 50,000= 400,000lb.

263 rod: 1lb 10oz. 1lb 10oz x (2000x2000)rpm=6500lb
1lb 10oz x (5000x5000)rpm=40,625lb. 8cyl x 40,625=325,000
I've not included the piston, rings, bearings, etc, but in the case of the 320, total inertial weight is well over 1/2 million lbs!!!! The life of your roadsmasher engine is in your rt foot! The weight of the 263 components is not insignificant, but it is lighter by a ways. By now it should be apparent that these engines have some problems. The real advantage of the 263 is that moderen up to date components can, with some work, bolt in. Seriously reducing weight. Moderen pistons alone are worth 5-6 hp a hole,= nearly 50hp.

Rod ratio. This is a numerical value arrived at by dividing the rod lenth by the stroke. I left this last because rod ratio is a very funny/odd thing, it can make or break a engine. It is tied directly to intake volume, if these values are not in balance the result can be a major unhappyness.
320; 8.25/4.312=1.9, a nice ratio!!
248; 7.625/4.125=1.85, not bad
263; 7.375/4.125=1.79, this looks like it going in the wrong direction, but with a shorter rod and deck, rod lenths can be juggled around to fit the intake dynamics.
The 320 looks like it has a really nice ratio but at 8.25 long its not so great. In all cases, a high ratio tends to make a small intake work better, which we have and a really big intake work nice, which we don't have, and never will. A really long rod has a tendency to stay at TDC and BDC for a rather longer time, hindering flow and a few other things, piston needs to be moving. 263 has a smaller intake but it can be opened up and flow vastly improved, and with a little choise in rod lenth, dwell time is reduced and the rod lenth would give more intake signal which would work much better with a "real" intake manifold. Could the 320 be built up to the same level as my 263? Possiably. Would it be easy? No. At that level would it "get" my 263? Yup. alleycat
05-18-2006, 07:34 AM
Fryguy: your personal settings are such that I can't send you any kind of email. Let me know what your email is or email me and I'll send you the pictures to post.:confused:

Riv, you can send the pics to my email address at

05-21-2006, 09:29 PM
Once upon a time, when I was going to the big school, I met some grad students that were doing a project on a small one cylinder engine. I've forgotten what the original expierment was because things rapidly went wrong. We discovered that the cooling system and how good or not good it is, has a big impact on power production. We found that there is a optium temp in a engine and lack of uniform temp control through the engine can and does cost power. The expierment ended up persuing that end.

With summer and hence, hotter weather, just around the corner and if anyone is going to build a all out engine such as has been hashed around in this column, the cooling system needs some upgrades.

The basic operation of the str8 cooling system is out the bottom of the radiator, through the water pump, out through the dog leg pipe and into the left front of the block, somewhat acrossthe block to the right side, then quickly drifts back to the left side to the back of the block and up into the head via the big hole at the left rear of the block in the deck. It then flows to the front of the head where the thermostat housing is, as this is the location of the systems pressure differential. By the time it gets here, it's HOT, providing little cooling, and the head is the place that needs it the most.
I've run my buick through some hot places and I've found it likes cool weather better than hot. I'll bet that most are that way. So what could be wrong with the cooling system? Look at the size of the radiator!!! And the guage hardly ever shows hot!? Well, 1st problem is the dog leg port. It puts the cool water right into the side of #1 cylinder. If the cooling system is nice and clean and in good order, it will cool that cylinder so well that it will distort the bore in that cylinder. Then the flow is mostly down the left side, leaving the right side hotter. The cylinders need to be cooled but the head needs it more. The 248 has no coolant transfer holes in the deck, except at the rear of the block. The 320 may be the same, I'm not sure, I don't recall. The later heads have holes in them for this, early heads may not, I've never had the opertunity to check. Head gaskets are punched for the holes. 263's have got the transfer holes in both the deck and head. I suspect that the head being poorly cooled, particulary in the exhaust port side, has a lot to do with all the destroyed rings&pistons I've found in all the str8's I've ripped down. The biggest problem is the big (1") hole in the rear of the deck. Water follows the path of least restance. That big hole is the least restant path, all those other smaller holes will get little flow. The hottest point in the head is the exhaust side and all the exhaust ports are side by side except front & rear. A odd thing happens when these sites get really hot, which is most of the time, the heat causes the coolant to burst into little steam bubbles on the surface of the metal. These little bubbles remove heat pretty good, unless they get togather and form pockets of steam, then things get really hot and things get bad. You can't hear this and the guage sender is in the wrong place to ever show it. The passage between the exhaust ports needs to flow. The stock system won't do this.
How do we fix this? All the holes at the rear of the block with the exception of the two holes at the very rear, need to be pluged. If the block is on the stand and bare, idealy, get a 3/4 internal hex pipe plug, thread the hole and crank it in. The 3 remaining smaller holes will take a SBC front oil galley plug, 1/4 pipe, I think, thread the holes and crank em in. Some of the plug should stick up. The block will have to be decked. This is the best way. If the engine is togather, put the plugs in the head. If you have a different way, go ahead, just plug em. Next, using the head gasket as a template, drill a 3/8 hole through the deck between the exhaust ports, if you have a early head and it does not have the holes in it, drill it as well. On the right side of the deck, opposite the just drilled holes, drill 1/4 holes. There diffinatly won't be holes in the head, so matching holes must be drilled as well. At this point we have now got a flow from the cooler bottom of the block between the hottest spots in the engine, the exhaust ports. This goes a LONG way towards equlizing temps in the engine, and its diffinatly ok at this point, but one more change makes it excellent. Eliminate the dog leg pipe. Make a block off plate for the port on the block. Fab up a pipe going from the water pump to the middle freeze plug port. I did this out of stainless steel bathroom grab rails. I put a little "jog" in the pipe just aft of the water pump exit, in order run it close to the block, machined up a o-ringed bung that plugs into the freeze plug port, drilled 3 holes in the boss, theres more than enough meat, a little silicone, and "bingo" the best cooling system ever. What this does is put the coolant through the widest cylinder spacing, over to the right of the block and front and rear split, pulling back across, up into the head, flushing the exhaust port space with a good steady stream. Excellent temp controll. alleycat
05-25-2006, 11:18 PM
Guys; I have emailed my lakes pictures to Fryguy and I am hoping that he can figure out how to get them up so everyone can see them. You will be able to see some of the cooling system mods that were made on that engine. I have not had a response from the emails I sent to the guy that built the car. I agree with alleycat that the Buick 8 has cooling issues. Alot of other inline engines, if not all, have cooling problems. Ford 300 sixes are notorious for wearing out the front cylinder because it sits right behind the water pump and cannot stay up to operating temp. I have had to offset my boring bar to get them to clean up at .060 over on the first rebuild when the rest of the cylinders will easily clean at .030. Also many other inline engines have copper water distribution tubes inserted in the water jackets, Chyrsler flathead sixes are this way. Triumph 2 liter sports car engines have a water distribution tube in the cyl. head. All are attempts to improve temperature variations along the length of the engine. So any improvments that can be engineered into the Buick will probably help the engine survive in todays environment. Many OEMs are reluctant to change anything on an existing design unless there are a large number of in-service failures or a large number of customer complaints. As long as the general customer gets a reasonable service life out of their product then hey, no problem. Given the time period that they were built and the way most Buick owners operated and maintained their vehicles, any shortcomings that were cooling system related were probably considered a nusance and not a problem requiring any design changes. Sorry if it sounds like I'm rambling on.
Jim Carmichael
05-26-2006, 04:22 PM
Allycat I also have had Delta cams do cams for my inline Triumph engines so we must live fairly close. I work at Valley Freightliner and one of the things the big truck engines did to help cooling was to reverse the flow of water so it hits the hottest part first. I don't know if that would help as it sounds like you have it under control.

I also have a 1953 Buick Super that I won't be using the rear end on as I am switching it to a 1962 frame.

I would like to build my 52 263CID up enough to tow my trailer as I don't need high RPM just lots of torque but I don't think I have enough smarts to do all you guys have done. What A Group!!
05-27-2006, 11:47 AM
Bigrivy is right on! Since most if not all inline engines derived from 4 cyl engines, and with a short engine all the cooling sourced from the front, everthing worked ok. Buick engines are basicly 2 , 4 cyl engines back to back and the cooling just barely works. I think that most if not all my engine failures are cooling related. I thought about a reverse flow system but it would have to come in the ends, not helping much. Then I thought of what I described earler here, and I think that these modifications will solve all the problems and would be a very good thing to do even to a bone stock engine. Considering todays driving climate and the gas we have to live with, if you want to drive your car and you want it to live....well...As a side note, when I first did this modification to my 248, the coolant temp droped by about 20 degrees, I had to block part of the radiator, even in the summer!! The radiator is too good! alleycat
05-28-2006, 12:28 AM
Alleycat, this is interesting, I thought that just 39's had the heating problems. Haha. Well Mine did, and after purchasing it in Provo Utah I started my trek back to my home in Riverside Ca. As soon as i got on the open road I noticed the temp going up. Finally I pulled over and lifted the hood I was greeted with a very hot blast of air and the radiator boiling. Well I happened to have my Dads old 'desert cooler bag' and we waited for it to cool. Back on the road i noticed that if i stayed at about 50 mph it would stay at a reasonable temp, but that wasnt a reasonable speed. I thought maybe blocking the hood up a bit might help. Well it sure did and then i could let er rip, and she got up and cruised at a good 70mph and kinda hot but not boiling. Later I decided to look for a cause and noticed that 39's didnt have much in the way of underhood ventilation, and remembering the scorching heat coming out of that blocked up hood i realized that it might have an 'air dam' effect, and the air was 'packing up' under the hood, slowing cool air thru the radiator. Well i just got under the cent, and looked around , and finally noticed that there was this big open gap under the radiator, and,the front crossmember looked like a regular 'air scoop'! It was causing a lotta air to go right under and behind the radiator causing a high pressure area. So with some sheet aluminum and some rubber mat i blocked that 'scoop'. Havnt had anymore heating problems since, maybe some extra louvres later. And Alleycat I might try your fix for engine protection. Any way its an easy fix and anybody can do it with either thick rubber or sheet aluminum and some sheetmetal screws. guys check your Buicks, you may have similar problems.
Buick boy
05-29-2006, 08:31 AM
I was thinking and like alleycat said, the straight eight is just two four bangers put together. what would happen if you blocked 4 cylinders? there was a guy running at the lakes who ran a SBC with only one side. is it possible to only run with 4 and if so, what kind of power would it make?
Jim Carmichael
05-29-2006, 10:12 PM
Reading this post I was thinking about the staged 2 barrel carbs on Ford Pintos and thought they might work well on the Buick. They might even fit the manifold as they are mounted with 4 bolts. I think they were a Weber design and worked real well on a Datsun I tuned for a friend with much better power and fuel mileage.

By the way I spent a pleasant few hours reading jiriky's web page, what a neat thing for him to do.
05-30-2006, 02:26 PM
Hi guys, just checking in - I've been building my house lately, and haven't found the time to write here. You have done a great job at keeping this thread alive! Why didn't I have all this info available when I started my project. :angry:The cooling stuff is pretty important, and what Alleycat suggested would basically have been easy to implement when the engine was in pieces. I recall the 1946 Shop Manual (supplement to 1942) stated there was a cooling modification that year, and that the earlier head gaskets won't work on a 1946 engine.

Now there's already so many need-to-do's along this thread, that I'll have to make a list to be at hand when the time comes. And it will. :thumbsup:
05-31-2006, 01:43 AM
BuickBoy; I think that the casual browser to this thread would think that most of us straight 8 guys are from another planet. Then you warp in from another planet in another dimension. The straight 8 is like two 4cyls. One 4cyl cut in half and hooked to the ends of another 4cyl. You would have to run on the middle 4 cyls. of the straight 8 but I think it would be a real dog. Its possible, I've seen a demonstration of a V8 running on one cylinder. But it labors considerably under the load of dragging the rest of the rotating assembly with it. I know you are talking about removing the other pistons and valve train but the same principles apply. I think that it would actually make less than half the power of all 8 cyls. working together. The reasons being everything listed in this thread already, high component weight, piston speed, friction, bad head design etc. The reasons they do this to small block chevys is 1) to meet a displacement rule of some class or sanctioning body and 2) to take advantage of the phenominal amount of research and development that has been done on the chevy small block. Arguably pound for pound the most versatile and powerful, for it's size, engine ever created. I would bet that more time and money has been spent on the chevy than all other engines combined. If I was displacement limited this is not the engine type that I would start with!
06-02-2006, 11:41 AM
Aren't we Straight 8 guys from another planet???!!!! Thats what I was hoping was true.

Just wanted to let everybody know that I am creating a thread called Bonneville Salt Racer. It has the pics that BigRivy(Kent) has sent to me to post. They are also in my gallery under Fryguy.

Check out the pics and let me know if you guys want them bigger or not. This racer needs to be seen in person!

06-02-2006, 03:23 PM
Hey fryguy, be sure to mention how to get to where the photo's are, as I, at the very least, am not worth spit at gettin around on a 'puter. I also lost you out of my PM file, so, in case you did'nt get my last pm, yah, it'll all bolt in, no sweat. alleycat
07-06-2006, 04:48 PM
You guys are too much!I must admit I havent read all of the post on this thread yet,I need time to soak it all in.Alleycat,would you be interested in building a motor for me?I am a retard at motors,but I can paint the crap out of some stuff!
07-07-2006, 09:43 PM
Possiably...Continue to read this post. It will give you a idea as to what can be done to these engines, and I've only spelled out about half of the stuff I do to these things. However, since you live on the east coast and I'm on the west, there are some logistics involved....Alleycat
08-24-2006, 04:00 PM
Alleycat, are making me dizzy!
08-24-2006, 04:17 PM
The pictures from Fryguy are in the racing section of the showroom.

click here (
Buick boy
08-27-2006, 01:50 PM
I was just wondering if they ever made a magneto for the straight 8? and also Hudson had a flat 6 that was fairly quick, I think it was like 307ci or something like that with dual cards (Twin H power) . I wonder how the that would fair against a 320 with dual carbs in a 1/4 mile shootout?
08-27-2006, 04:43 PM
At the Antique drags out here in Ca. ive seen a hudson 6 race a pretty quik 38 buick century coupe, and the Hudson won. And also a couple of years ago at the San Diego vintage road races an old nascar replica Hudson could pretty well stay with some of them Mustangs on the straightaway! But Mel Tull has done 170 at Bonnieville in a 32 ford roadster, with a roadmaster/century straight 8, Dont think a Hudson has done that yet??

check this out
08-27-2006, 05:00 PM
Yes there was a mag that was made for the Buick strt. 8. It was a Ronco, Vertex, Scintilla, magneto. It is now being reproduced for the traditional rods in a HEI form and adverised in the hot rod magazines.I dont think they have a Straight 8 Buick one but the Pontiac HEI is almost a clone of the old Buick distributor, [cept the pontiac rotates opposite way]
08-27-2006, 06:13 PM
Sure, there's mags for the str8. I don't think that I've seen any on Ebay or such, but I'd guess that vertex or scintilla could make one up. As 39cent says that they all made 'em, probably still can! Trouble is, while a mag certainly looks cool, moderen electronic CD type ignitions work better.
Now, the hudson vs buick, I have to agree with 39cent, Hudson. Why? Hudson was very serious about their cars being fast, and hence, the engines. A really good breathing flat head is better than a bad ohv engine in spite of the seeming advantage of ohv. The buick with a well prepped head and the duals? Well now, that may be intresting! alleycat
08-27-2006, 06:38 PM

Well i guess I,ll have to put up or shut up on my claim of the "Toyota mystery head!!" The 2 Toyota heads that Mel Tull welded together, for his Buick 320 straight 8. I have to find that mag article. or get ahold of Mel for some pix! Just think! a 16 port hemi overhead cam head!! and its gotta get all the horses and torq to pull under 5000 rpm. wud be awesome on a 263!
Buick boy
08-27-2006, 07:08 PM
all I have to say is wow...
08-30-2006, 08:41 AM
Hey 39! If you could indeed find any info on such a head I would be hugely intrested, even if its not a working head, perhaps a different viewpoint could see a way that it could become working.
A intresting thing I've figgured out while doing some background work on my str8 preformance book. I am highly suspicious that the boys at buick DID build a much better head for the str8! And, I think that they made more than 1. I'm also about 100% sure that the story about buicks str8 in about 1938 is vastly different than what we think or have been told. Soon as I get a few more ducks lined up I write more. alleycat
09-21-2006, 02:18 PM
This is what I found about Mell Tull and the toyota head, by browsing the net..
I will keep on looking for more on this!
09-21-2006, 10:14 PM
I met Mel Tull at one of the Buick club meets, he also had a 39 century 4dr. It had homemade stainless steel headers, dual 4barrels, and a Hone overdrive. said he was getting pretty good mileage too. we got to talkin and he mention his DOHC Toyota head set up and some other things he had been doin, i was blown away. His roadster was featured in a 'Tex Smith Hot Rod Mechanix' mag of which i have, but cant find! He said his strt 8 ports were copies of chevy ports, well i want to see that? His roadster was really a cut down 32 ford 3 window cpe. body. [thats what they did way bak] and he set his buick up with racing headers, and a huge holley 4bbl wen he went to bonneville. Anyway he,s a wealth of information on strt 8,s . GADS they dont recognize DOHC headsfor x and xx at Bonneville??? well seems an old gent from New Zealand got a few records on a bike he modified! they didnt want him to run iether. So what if they dont recognize it!! ggggg who cares he still would be among the fastest of his kind. He just wont get the Bonne trophy! But everybody would know he had the Bonne spirit! Isnt that what its all about?
09-23-2006, 12:05 PM
A very interesting thread going back 9 months to Alleycat and Jryki.
I guess we have been very lucky or the key to making the 320 spin is a blower.
At Bonneville this year we were turning 5100rpm at 143+ mph in a relatively stock bodied 1950 super. We have the 320 with good Venolia pistons and rods, cadillac valves and bb valve spring with an otherwise stock valve train and head.The cam was ground for the blower.
Some old timers that used to race dirt track around here told us not to spin her over 5500, so we have always shifted at 5200. We had our eyes on 150 mphwere thinking about pushing to 5500 next year. After reading what some pretty smart guys had to say, we might just go to a taller gear instead.
09-23-2006, 05:32 PM
You guys are awesome. When I'm driving my '53 down the road at 75 and it feels like it's going to lift off, I stop and think about doing 143 in that thing! What a cool car!

07-30-2007, 10:38 AM
My project is a '40 Super with a 263, hyd. lifters, .075 milled head and dual carb./exh. Strictly a driver/ non-racer engine backed up by a 700R4 and 3:27 gears. This winter's project will be a throttle-body f.i. on a single carb manifold. I recently read your comments on the poor fuel distribution with the single manifold and that the dual carb manifold was much better. How about retaining the dual manifold, fab a center mount plenum for the f.i. and run header-type tubes to each carb mount?
07-31-2007, 12:30 PM
Thats not a bad idea at all. I've only mentaly fooled around with the idea of fuel injection, and it could eliminate fuel distribution problems that the str8 has had since, like day one!. Over on the "whats new with the str8 hot rodders" thread, the red buick there is fuel injected, I only basicly get what that guy did, but that car is so over the top....So obviously, it can be done. You have the right engine, it can make a ton of power. You really can't hurt it, I think its worth a try. alleycat
12-02-2007, 05:33 PM
I just sold my 37 Century for health reasons, now I find out things may be okay after all. In any event one of the things that I have been screwing with is a Honda flat six Valkyrie. I know its not a Buick, but what I am in the process of doing is adapting a MSD crank trigger wheel to the 6. Then the MSD systems can be used, they have the drivers for fuel injection, special retardation circuits for blowers, (which I will be running) plus retards for NOS. This may be an avenue for better ignition for a straight eight.
02-02-2009, 10:27 AM
Alleycat, what have you been up to lately? Any progress on writing the book? :waving:
Buick Guy
02-02-2009, 11:51 AM
Look at the Electro-Motive site. Their system combines the ignition system and EFI, even allows for full sequential setup. Just a thought. :waving:
02-03-2009, 02:14 PM
Hi jyrki! I am in the middle of building/rebuilding 3 engines, my ford exploder which "exploded", my 409 chev, and my 248 for my 50, along with beating nails into the house! The 248 is going to be a "take no prisoners" kind of build up and its sort of my test subject for the book as I do everything to this engine, it goes into the book. This has gotten rather into a bigger project than I initally thought! I've done a few papers but nothing like this! Main problem is that practly NOTHING is really known about these engines. I'm putting the finishing touches on the rod section, then its on to the crank. alleycat
02-04-2009, 11:14 AM
Glad to hear it's coming together :hurray:
02-04-2009, 08:58 PM
Dont get me wrong st8 are cool looking but as time goes by parts are becoming more rare some times might need to improvise like u guys have been talking about a 350 chevy or buick parts are way cheaper there is just so many things u could do with them to buy a rebuild kit for a chevy and have 64cc heads your buick will fly under 1000 to 1500 with modern high performance parts:shifter:
02-05-2009, 12:43 AM
20 years ago I might have considered swapping in a SBC, but 10 years ago, when I started building my Buick, it was out of the question for me. I have seen too many SBC's - it's plain boring. Even a nailhead Buick would be a better choice. Ten years ago very few of my fellow rodders were able to understand why I kept the S-8. All the streed rods had an SBC. Now all the rods I see around have a flathead. I love it!

The S-8 is something different, not just an easy-way shortcut SBC. Part of the fascination when building a S-8 is that no performance parts are available, so you have to get creative and improvise, just like the true pioneers of hot rodding. And it's amazing how much power you can get out of these engines, at will.
02-05-2009, 07:08 AM
In my opinion, nothing belongs under the hood of one of these things but a Straight's what makes it a Buick.
02-05-2009, 07:29 AM
Dont get me wrong st8 are cool looking but as time goes by parts are becoming more rare some times might need to improvise like u guys have been talking about a 350 chevy or buick parts are way cheaper there is just so many things u could do with them to buy a rebuild kit for a chevy and have 64cc heads your buick will fly under 1000 to 1500 with modern high performance parts:shifter:

Hell..........If all I wanted was an easy life.......I would have never picked the Buick straight eight
Buick Guy
02-05-2009, 07:40 AM
Very neat! Doug
02-05-2009, 08:54 AM
Here is some of the parts that are going into the 50 Buick engine.
02-05-2009, 09:25 AM
The reason most people like the Buick Straight 8 is that they are strong reliable engines. They can be modified for improved performance, but basically can still be driven daily for transportation. Back in the day, they could be driven across the US with no problems. They arent that bad on gas compared to other antique cars.
02-05-2009, 09:29 AM
here is some of the parts that are going into the 50 buick engine.

holy moly!
02-05-2009, 01:36 PM
I agree, leave the straight eight in it. All I want to do is add twin carbs and would like to do a overdrive of some kind. Before I tore it apart it went along with traffic good, rpm's a little high on the expressway but ok.
02-05-2009, 01:38 PM
Saltracer, Gary, Doug, and everyone, keep those pictures coming, I just can't get enough :bana:

Gary, did you get that piece of art (aka cam) from Howards?

Alleycat, are you going to save all your pictures for the book, or could you provide us with a peek?
02-05-2009, 11:22 PM
Absolutly!! The book is a secondary project! As I finish up the parts, I photo them and when I get a bunch I'll post 'em. alleycat

Saltracer; like the headers!
02-06-2009, 08:22 AM
jyrki, yes the cam came from Howards, Donnie Johansen. We had it degreed in yesterday, it was right on the money. We installed the crank Tuesday, used Plastigage and had to shim the mains .001", installed cam and timing gears and chain. MIke is off Monday, we will put in the rods and pistons, oil pump and pan. Another guy that does machine work for us is making the bungs for the EFI injectors.
02-14-2009, 10:10 AM
Gary, who made the rods? alleycat
02-15-2009, 02:20 PM
Alleycat, Venolia had someone make the aluminum rods for us back in 1999, we think they are GRP, but not for sure.
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There's a book, from the early 1950s, which is about hot rodding Chevy and GMC 6-cylinder engines.  There IS a chapter in it about the Buick Straight 8 engines, too.


Reading that book, where it defines "half-race" and "full-race" camshafts, plus "regrinding" camshafts, for improved performance, you have to realize that back then, you modified what you had rather than order up something from CA or the east coast.  It also mentions mixing fuel with various "enhancers", too!


The main reason that dual carbs would really work is that it not only put some additional air flow into the engine, but it also made it easier for the air to get in (not having 1/2 of the full length of the motor in the right-angle runner design intake manifold).  One of the reasons for the success of the Chrysler Slant 6 was because the only (real) right angle in the intake system was at the bottom of the carb plenum, rather than near the intake port in the cylinder head. 


A while back, there was a thread about "re-designing the Buick Straight 8 with modern technology".  You might move it here, Mr. Earl!  OR put a link to it!  Might even reference the Inliners International club, too.



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Posted (edited)

Back in my USAF days, spending quite some time in Columbus, OH, there was some guys in a gas station running 6 Chevys in local stock car tracks beating the flat head V-8 Fords.  So, I was able to by a surplus '34 Coupe, 3 window from them at a good price. Hauled it across PA, only to sell it off for a '55 Ford to keep from doing a rebuild.


Lamar, I enjoy this thread and hope it flourishes, although I do not plan any Mods to my '32, or hood louvers either.



Edited by jscheib (see edit history)
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Going to resurrect this thread with some related information.


I think the Chevrolet OHV, inline six, produced from 1937 to 1962, also known as the "stove bolt", was something like a little brother to the Buick OHV straight eight. The early fifties book (yellow and black cover) that NTX5467 refers to is "How to Hop-up Chevrolet and GMC Six Cylinder Engines." I got my copy as a gift from the father of a high school friend who raced dirt tracks in the 1950s and 1960s. I asked him what he thought of these sixes and he responded, quite enthusiastically, that "Those were good engines! I won a lot of races with those engines."


He did NOT have anything good to say about flathead Ford V-8s. Actually detested them.

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Posted (edited)

A few comments about the compound carburetion:


(1) Buick was experimenting with multiple carburetors somewhat earlier than 1941. Some of the "in-house" Stromberg documentation shows Buick interested in dual ONE-BARREL carburetors as early as 1935.


(2) The compound carburetion as produced by Buick was really pioneering in the field (some pioneering is good, others less so). While Buick was certainly not the first American manufacturer to use more than one carburetor on an engine, as far as I can determine, Buick was the first to use "progressive" linkage with multiple carburetion.


(3) It didn't work well! OK, before my time, but my Dad told me that fuel economy was horrible, and during WWII, fuel was rationed. According to Dad, ALL of the 1941 Buicks in our area (north central Missouri) got retrofitted with a single manifold and carburetor. I have seen this since, with many customers and prospective customers wishing to refit their Buicks with compound carburetion. The cost of the single manifold and carb was insignificant when fuel to run the compound carburetion simply was NOT available.


(4) As mentioned by Willis in a post above, the success of compound carburetion is due to better average fuel density distribution among the cylinders. For this reason, we started selling and suggesting to others to leave the original compound carburetion to those that were showing their vehicles; and to use two primary carburetors with solid linkage for driving. So far, all of the feedback has been positive from those who have done so. The use of 40 series post-WWII single carbs (either Carter or Stromberg) on 60 series engines works exceptionally well, and these carbs are much less expensive than the correct compound carburetion carbs. For the 40 series engines, there are some Carter WCD's used by A.M.C. that work well, and again are not overly expensive, but obviously, there is no Buick starter switch on the A.M.C. carbs. Personally, I like the tunability of the Carters over the Strombergs, but not everyone has a lathe capable of machining metering rods for different calibrations.


(5) Finally, while intake manifold design is NOT my area of expertise, I believe that an intake with more rounded runners than the factory intake would significantly improve performance. REPEAT, not my area of expertise, just my opinion. For those with aluminum welding capability that might be interested in attempting this, think thick aluminum electrical conduit. The conduit is available in a number of different degree bends. Several customers with antique cars wanting to use multiple carburetion have used conduit in this manner.



Edited by carbking (see edit history)
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Just imagine 4 old Jag S. U. carbs on a log manifold with 8" runners into the ports.

'nuff to make a colonist weep.

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10 hours ago, FLYER15015 said:

Just imagine 4 old Jag S. U. carbs on a log manifold with 8" runners into the ports.

'nuff to make a colonist weep.


 Try it, you might like it, Mike.


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