'65 425 - valve geometry & carb questions

[Guest skilly65]

My son bought home a '65 Riviera 2 door coupe to NZ nearly 3 years back. He bought it in Cape Coral, drove it to Miami, filled it with all the parts for a restoration and shipped it here to Auckland. The car was built in Flint, Michigan.

 

Once I pulled the heads off (Dad does the engines!) the bores looked a bit big for the 401 Nailhead that he had been told it was. Turns out it was a 425 Nailhead, with some deeply scored cylinder bores, two pirate pistons (6 were Buick un-bored originals and 2 were unidentifiable oddballs), and all the rod numbers/pistons had been thrown back in by a blind mechanic. Rods 2 & 5 on journal # 4 etc. The whole front damper assembly had been repainted Buick blue, then jammed through the front oil seal, paint & all.

 

We have had to bore the cylinders to .040" oversize to eliminate the bore scores (it looks like something like stones or plug electrodes had been dropped through the plug holes) and fitted new Egge pistons. Rods have been re-sized - crank journals all ground .020" undersize (they had been ground to 0.010" under in the US, but were tapered!) and all the main bearings were deeply scored on arrival in NZ. New camshaft (standard spec), lifters, & bearings, new oil & water pumps, timing cover, dizzy, exhausts, engine mounts, etc, etc. And a bit of chrome to go on top (air cleaner, rocker covers & valley cover). We had ordered a new 600 cfm Edelbrock carby, thinking the engine was 401 cu inch, but now have to get a 750 or 800 cfm carb.

Can anyone advise whether the Thunder AVS or the Performer is the better model to have on this engine?

 

Total strip down of the body - all new floor panels throughout - rust cut out of the front ventilation ducts - body bought back to perfect condition & primed - chassis separated from body and now looks a million dollars with all new brake & fuel lines, etc - disc brake conversion done - new steering box & linkages - new fuel tank - all electrical looms replaced & blue tooth/digital radio etc installed, but behind original facias so all is hidden. My son has done everything except the engine & transmission.

 

The numbers don't match - from the volumes of paperwork & manuals supplied with the car, it looks like the engine swap was done between January 6th 2004 and January 7th 2005 by an owner in Michigan - this is where the engine number was changed on the title papers. The 425 has all the correct ID markings for that engine size, and the trans is a '65 LX SP400, with a positraction diff fitted in the axle. So, did all the running gear come from a '65 Skylark or similar? 

 

So, all the work is nearly done. The mileage on the clock is 93,000. I just have to finish the engine rebuild, but have encountered a minor snag. The valve seats have been previously recut so deep that our (new) valve stems are all between 0.100 and 0.120" above the 1.54" as stated in the Buick rebuild manual (and the new valves are the correct length according to the book). As we are using Best gaskets composite head joints that are about 0.045 thick when compressed rather than the original 0.015" steel gaskets, the problem reduces a little. From experience, could anyone advise me whether adjustable pushrods would be a good solution to eliminating the rest of the over-height valve stem problem?  I don't want to grind down the valve stems unless I really have to.

 

Cheers,

 

Tony

Auckland, NZ

 

Sorry - didn't intend to write a book on the subject!!

[Guest skilly65]

Since starting to explore this forum last night, the engine data page advises me that the 1965 425 engine we have has an 'LW' code, so it seems it could be an 8.25:1 low compression engine. Does anyone know if the compression was lowered by piston dome size reduction, or by increasing the combustion chamber volume in the cylinder head?

 

Having 91, 95, and 98 octane petrol here, it seems a shame to run it as a low compression engine when the potential is there for a higher output.

 

Cheers

 

Tony

Auckland, NZ

[carbking]

Tony - the original Carter 3923s AFB used on the 425 is EXACTLY the same size (625 CFM) as the 3921s used on the 401 engine. While the 3923s is less common than the 3921s, unless you are building an absolutely numbers matching show car, it would be relatively easy to recalibrate a 3921s to 3923s specifications. The primary side is slightly leaner for the 425; while the secondary jets are significantly richer for the 425.

 

Either would perform much better than one of the modern clones; plus everything will fit without modification.

 

The primary side is close enough (less than 1/2 calibration size) to just leave alone, and either fit the correct secondary jets, or drill the originals oversize by 0.007 inch(0.082 -> 0.089 inch). The correct Carter part number for the secondary jets would be 120-159 which was superceded by 120-389. DON'T buy clone jets if you do this. Stay with original Carter, or just drill out the originals oversize.

 

Jon.

[RivNut]

LW is a high compression engine.  The first letter, L, is a sequential letter used by Buick to designate the year; this system started some time ago.  H=61, I=62, J-=63, K=64, L=65, and M=66.  The second letter designates the cubic inches.  T=401 w/ 4 bbl carb, W=425 w/ four barrel carb, and X=425 w/ two four barrel carbs. So an LW engine would be a '65, 425, single four barrel engine. Except for export engines, the compression ratios (advertised) for the 401 and 425 were 10.25:1.  The factory called for a high octane fuel for the high compression engines.  If you've got 95 and 98 octane fuel, your engine will be very happy, and so will you.

[telriv]

With those Egge pistons they will more than likely be .060"-.065" in the "Hole". From the factory the best I have EVER MEASURED/SEEN is about 9.75-1. This is with a piston in the "Hole" of about .040". RARE. More commonly they are in the "Hole" around .055". Approx. 9.5-1. Using these pistons & the Best gaskets you'll probably end up with around 7.8-8.2-1 compression. Now this throws the "Squish/Quench specs WAY OFF/OUT OF WACK!!!!!. "Nails" seem to run best with no less than .025" & no more than .050". Now we know why one engine runs better than the next. From the factory (at .040" + head gasket of approx. .015" = .055". Just on the outside. With .055" + .015" now = .070". With the set-up you're about to use you could end up with .065" + ,045" = .110". WAY OFF FOR PROPER RUNNING, EFFICIENCY & DETONATION resistance. Because of the "Nails" Pent Roof combustion chamber design they can tolerate a REAL 10.0-1 to 10.25-1 compression ratio using today's fuel. I usually make them 10.0-1 on many of the stock type builds I do. At a ..040" overbore on a 425 the bottom of the block should have been filled with an Epoxy to help keep the cylinder bores from flexing & stabilize the bottom end. This helps the re-build last longer before blow-by becomes an issue & the re-build has to start over, AGAIN!!!! Hopefully you "Sonic" tested the block BEFORE boring. Because of the weight of the reciprocating assembly cylinder wall thickness needs to be approx. .150" thick. Most 401/425's aren't this thick from the factory WITHOUT an overbore.

I get asked/called constantly why the engine they just had re-built doesn't seem to run as well/powerful as the old worn out engine that was removed. NOBODY pays attention to the DETAILS!!!!! Many are trying to re-build the "Nail" using SBC tactics on the CHEAP!!! AIN'T GONNA HAPPEN!!!!!  IF YOU WANT IT TO RUN GOOD, LIKE IT SHOULD IT COSTS$$$$ TO PAY ATTENTION TO THE DETAILS!!!!

About the valve seat recession. One of the things I normally do in this situation is to use SBC valves. I take 1.940" intakes & cut them down to 1.900". Use 1.540" or 1.600" exhausts & cut them down to 1.520". This now puts them at a new seating area to re-finish the valve seats. This will "Repair" the proper valve heights. NEVER try to install hardened seats. Many/Most times you will cut into water. Especially on the intakes. If they don't leak today give them 6 months. I would be willing to bet they will start!!! You need to get valves that the total length is about factory "Nail" length. So they need to be cut to length also. Make sure the tops of the valves are hardened deep enough & can have AT LEAST .100" removed from the tips. They will be required to use 11/32" valve guides. I've had them made just for our beloved "Nails". DON'T EVER TRY LINING THE GUIDES. Because of the EXTREME side force put on the guides because of the short, stubby rocker arms (Much amplified by a higher than normal lift cam) the liners usually fall out of place. I don't care what you or the machinist does, they WILL dislodge themselves.

Using SBC valves now gives you a Pandora box full of options as far as springs, retainers, valve locks, etc.

I realize it's more than likely TOO LATE in your situation, unless you want to start over.

I could type with one finger for days & not give enough INFO.

 

 

Tom T.

[Snake]

first off  a happy  new year to all, I seem to be in the same boat, I noticed the egge .030pistons somewhat in the bore plus using the best gasket will also cut down on compression. the head I have were resurfaced as well as ported , the cam I chose was a isky 270 int dur 280 ex dur .469 int lift and .496 ex lift. on a 110 LC , my question is this do I need to check  for valve to piston clearance or is there more of a gap now. Im also using adjustable pushrods on this build.

[Guest skilly65]

I wish to thank those people who have replied to my questions.

There is very little 'Nailhead' experience down here in NZ, so thanks for your time & knowledge.

 

And Ed, with the readings I have obtained, it would seem that I do currently have a 'low compression engine' stripped down in my garage.

Hopefully, with the assistance I am receiving here, we should be able to get the compressions back up where they should be.

 

Jon, your knowledge on the Carter AFB is invaluable. We may well get the Carter reconditioned and refitted, and will use it to get the baseline

data on the engine performance. Then, when the Edelbrock is installed we will immediately be able to see what is good and what isn't. Thanks

 

Hi Tom,

 

Many thanks for your reply - it's had me doing a lot of thinking while away for the New Year (and hope you had a good one too!).

Once I started Googling around with the right questions, your answers kept popping up on forums all over the place.

Gotta thank you for posting the problems/solutions you encounter while rebuilding these engines - it definitely helps people like me

down the bottom of the world to get a sad-state engine back up to a respectable running condition again.

 

Fortunately, the heads were not yet fitted as I was still pondering the seat recession problem. Progress won't be fast as I go back to sea this Friday till the end of February.

 

So, anyway, I rolled each piston up to TDC using a DTI directly above the gudgeon pin, then took 8 readings on each piston with the depth gauge (I'm a marine engineer, so usually work with much larger engines, but it's handy having all the instruments when these 'small' engines need some attention!).

This Nailhead definitely hasn't been blueprinted, as the 'in-the-hole' measurements (take 8 readings around the quench ring, then average them for each cylinder) varied by 9.5 thou", with the average readings themselves ranging from 0.0672" in-the-hole- to 0.0767". So, using the Best gaskets of 0.045", I am up to 0.1122" to 0.1217" over the 8 cylinders. Not good!

 

The block faces appear to have only had a very light skim in the past, so I am going to pull the pistons and get the machine shop to take 0.030" off the decks, then reassemble the short block (any advice on whether this is a good/bad idea will be gratefully received). With the valves assembled in the heads with only one spring, I will then nip the heads onto the block faces with a Best gasket (fortunately, we bought extras), bring each piston to TDC, then manually open each valve with a bar across the stem top, and measure the valve opening with a DTI on the spring cap until interference. From this reading I will then be able to calculate the valve/dome clearance when assembled & torqued down. These readings will determine whether I need to machine the Egge domes or not.

 

The above tests will also help decide whether I throw away all the new valves & springs and try to overcome the recession problem using SBC valves & re-cut seats to pull the valves back down in the heads. The original Buick factory manual (printed 1964) that came with the car states that the absolute maximum valve stem height is 1.590 for correct lifter operation, so they allow an extra 0.050 above the recommended max stem height. The remaining extra height can probably be accommodated with adjustable pushrods.

 

All the above work/parts acquisition/time frame is very dependant on the depth of the son's (the vehicle 'Owner') pockets - he works in the offshore oil & gas industry, and over 300,000 staff have been laid off so far since the oil/gas prices plunged downward. It could be a long, slow job. Considering the car & restoration parts were all purchased in 2011 and the container arrived in NZ in early 2012, you can see that things do move slowly on this project :-)

 

Cheers, and thanks to you all,

 

Tony

Auckland, NZ

 

ps - Just been doing some more measuring - this time the piston dome heights.

 

Buick original piston dome heights (on 2 random used pots) = 0.3251" and 0.3184".

 

Egge piston dome heights (on 2 random new pots of 0.040" oversize) = 0.3522" and 0.3530".

 

So, be aware that the Egge domes are .034 - .035" higher than the Buick originals. Maybe they are trying to compensate for the compression height reduction??

 

Tony

Edited January 6, 2016 by skilly65 (see edit history)

[telriv]

Decking the block is usually not a good thing to do as it now weakens the top end & sealing could be a problem. Also the sides of the pistons domes could come in contact with the heads. So material MAY have to be removed on the sides of the piston domes further lowering compression. Why not just get a set of the original shim steel gaskets that are approx. .015"-.016" compressed which would negate removing material from the deck & saving on machining $$$$. All my custom made FORGED pistons take into consideration ALL the shortcomings of the original design. AND they include the proper rings.

[Guest skilly65]

Hi Tom,

 

I thought all those steel gaskets had been used up and were now 'unobtanium'!!

 

I used to use them in my race/rally cars back in the '70s, but that was Aussie Holden V8s.

 

What sort of $$ are we looking at for your forged pistons and a set of steel gaskets?

 

Cheers

 

Tony

[RivNut]

BEST still makes them.

[Guest skilly65]

Best may not be the Best anymore - they didn't know who could supply these items.

 

Cheers

 

TonyS

Auckland

 

 

We do not offer .015 steel shim head gaskets. I'm not sure who would have these.

 

 

 

Roy Lucero

Best Gasket Inc

[RivNut]

I just got a set of BEST gaskets for my '64 and they included the steel head gasket.  I just assumed that they were the 0.015" ones.  Once again 'assume' takes on that ol' meaning.

[60FlatTop]

Be sure to check for wear on the bottom side of the valve rocker arm shafts. It's a high wear area and a lot of lifters have been replaced because of misdiagnosed rocker shaft wear.

Bernie

[Guest skilly65]

Thanks for the heads-up Bernie. I did find the shafts were worn in this area.

I now have two brand new shafts sitting in a box in front of me!

 

After reading stories about the steel rocker arms (and I have 2 bags of those here as well), I will be gently dressing the finger pads on the original aluminium items and reinstalling them. Some of the pads have hardly any markings on them. Although the car shows about 92,000 miles, the 425 was only installed 10 years ago, so there shouldn't have been all that much wear in it. It just looks like it wasn't maintained/overhauled correctly.

 

Cheers

 

Tony

[Guest skilly65]

Tom,

 

My idea of skimming 0.030" off the decks came from your forum comment to someone in 11/2013 about skimming 0.040" to get everything right.

Have there now been problems in this area? I have just read somewhere that the Egge pistons can touch the heads if the domes are not reduced, so that will drop the compression as well.

 

We actually bought these Egge pistons (and everything else we thought would be needed) while swanning around in the Atlantic Ocean in August 2011 (and the satellite internet from the ship was painfully slow!!).

Had to buy all the bits and get them into the car trunk before it was containered to NZ.

If I had known you had developed these forged pistons to overcome all the problems we are now having, I would have purchased them, but they weren't available in 2011.

 

I'm going to advise the owner to go the forged piston way, so can you please give me some details and $$ for them.

 

Using the forged slugs, we can stick with the Best composite gaskets, which are readily available, and will make future rebuilds that much easier. The owner intends to keep the car 'forever' he says!

 

Cheers

 

Tony

Auckland

Edited January 7, 2016 by skilly65 (see edit history)

[telriv]

That "Skimming" was actually .042". This was to bring the compression up to 11-1 as advertised with the pistons being used. NO, I don't recommend shaving that much from the deck. Normally, most from the factory are pretty good/close. I've ONLY had one that was way off. It happened to be a '66/401/ The deck on one side measured . .0135" front & .0075" rear. Was the opposite on the other side .0075" front & .0135" rear. So were thought that a .006" deck cut would be enough, but after cutting the .006" on the outside of the block there was still more material to be removed. We then checked/reset the block & it turned out to be the same. An additional .003" had to be removed to get the block flat/squared with just a touch on the outside edge not being cut. Same was for the other side. So we actually removed a total of .009" from each side to "Square" it up. We ended up with a finished deck height of 10.004". Most stock 401's are somewhere between 10.010" to 10.020" & are pretty consistent side to side normally not being off by more than .001" to .002". 425's are a few thousandths less at 10.003 to 10.012".

I ONLY have a few steel gaskets left in stock which at this point in time am not willing to sell unless I came come up with more some time in the future.

    As far as pistons & cost go. On a single order basis they are $915.00 US + shipping of course. If five or more sets can be ordered at the same time the cost will be lower by about $100.00. They are made from 4032 material & can be set, clearance wise, as tight as .0025" clearance, but would rather see .003" on 401's or .0035-.004" on 425's. On ALL the builds I've done to date there is VERY LITTLE to NO rattling or none at all when cold. After a couple minutes running time ( and I mean ONLY 2-3minutes) it's not noticeable at all even with a completely stock/quiet exhaust system. Each set is CUSTOM MADE FOR YOUR APPLICATION. Keeping this in mind I need ALL the specs. to get the proper pin height & dome volume for the compression ratio your looking for. Specs. are compressed head gasket thickness & bore diameter, I  don't think the compressed Best head gasket thickness is .045" as you said (probably closer to .035"), finished con rod length after rebuilding, stock stroke or stroked, finished deck height after squaring, combustion chamber volume (cc's) after finishing valve job, rebuilding, porting, actual finished bore, (the pistons can be made to accommodate a bore you already have), depending on bore diameter 1/16" rings can be used for a 15HP increase due to less drag & there are NO issues with performance or longevity, or the stock of 5/64", pin diameter being used (stock is 1"), the IDEAL compression ratio your looking for/at.

    The pistons took a little over two years to come to fruition. The top ring land is .300" thick as opposed to stock of .200". What this accomplishes is to help ward off detonation issues from poor/lack of tuning skills. Not that the "Nail" has detonation issues to begin with because of the original combustion chamber design. The stock "Nail" because of it's combustion chamber design can tolerate 10-1 to 10.25-1 compression ratios on the available fuel available in the US. I build MOST of the st-ockers I do at about 10-1. They can accommodate floating or pressed pins (as stock). Have a tiny groove in the top ring land above the top ring for getting combustion pressure behind the top ring for better sealing. A groove cut in the middle, 2nd. ring land to help prevent the 2nd. ring from "Fluttering". In ALL 1/16th. rings the top ring is Moly, the 2nd. ring is cast & the oil  is 3/16th. quality oil ring. In ALL 5/64th. it depends on what is available at the time the order is placed. I can get you ANY ring & bore diameter available in available sizes. These are ALL standard type rings. Additional cost for anything fancy,  a gap-less top ring, 2nd. ring, 1mm. etc, They are a "Slipper & Wavy Skirt" design so NO additional coatings are nec. because the design helps to retain oil for lubrication. Being a forged piston they are actually heavier than cast, but, because of the skirt design weigh about the same as stock. The pins are actually lighter than stock. The pin is made from 5100 steel & is MUCH stronger than stock that's why a shorter pin of 2.700" can be used on a 401 or 2.800" on a 425 which because of the pin weight of around 145-150 grams makes the piston/pin assembly lighter, than a stock pin of approx. 225 grams. Can accommodate up to 600HP & MORE with the proper tuning skills. Much of this WON'T matter because of the stock type nature most of them are going to be used for. Just gives you a better feeling they won't crack like stocker type cast replacements if pushed a "Little" further  than normal. The sides of the piston domes are rounded to prevent ANY head contact. They are designed for a 1.940" intake valve with enough radial (side clearance) & a valve pocket depth to accommodate a .700" lift & will fit either left or right as stock.

    The price includes pistons, of course, pin fitting, & quality rings offered by Hastings, Total Seal, Sealed Power or Perfect Circle.

I think I've covered it ALL. Any questions just ask.

 

 

Tom T.

[telriv]

Forgot to add. If you go with a MAJOR decking of the block & the additional costs for shim steel head gaskets & you get the PROPER rings to go with those pistons your getting close to the cost of the pistons with rings than ALL the additional steps required to get the compression ratio some where near stock or 10-1. Stock replacement CAST pistons normally go between $350.00 to $450.00 for a set. Now add in rings & the additional costs for decking & shim steel gaskets the cost difference is minimal IMHO for the added security of a more modern FORGED piston design.

[telriv]

On another note.

Ed, I would like to see pictures of those Best steel head gaskets.

 

 

Tom T.

[Guest skilly65]

Hi Tom,

 

We had the big chat last night, and we are going to purchase your pistons.

 

I am currently at sea, but should have all the information you require by about January 25th (providing they let me off the ship on the 18th).

 

The variations in piston height that I recorded (9.5 thou" over the 8 pots) has me wondering if the variation 

came from the Egge pistons (pin height differences) or whether the rods were not re-sized uniformly by

the machine shop. I need to find that out.

 

So, the intention in the short term is to get the short block correctly assembled, using the forged pistons.

 

I thank you for taking the time to forward the information you have, so we could make a decision.

I am not too many years short of your total, and this has been a lot of typing for my two active finger as well

If you would please e-mail me at skilton.adscan@xtra.co.nz so we arrange further details.

 

Cheers

 

Tony S.

Auckland

[RivNut]

On another note.

Ed, I would like to see pictures of those Best steel head gaskets.

 

 

Tom T.

Tom,

 

They're still in the sealed package, when I'm at the point of installing them, I'll take a picture for you.  They're the ones that come with the BEST gasket kit.  I was told they were steel gaskets; am I going to be in for a surprise?

 

Ed

[telriv]

Maybe????

[Snake]

I have Best gaskets on my build, they are steel showing around the cylinder rings about 1/4'' and fiber gasket covering the entire gasket.

[RivNut]

Hmmmm. I imagine that those are the same ones that I have. Hopefully they won't leak like the Fel-Pros do.

 

Ed

[1965rivgs]

Hmmmm. I imagine that those are the same ones that I have. Hopefully they won't leak like the Fel-Pros do.

 

Ed

Ed,

  I know I have seen a claim on the Internet that Fel Pro head gaskets leak but I have never experienced this problem after, say, 10 Fel Pro rebuilds. I have, however, experienced head gasket leaks on the original steel gaskets. This is the reason Tom T plugs the oil feed hole in the rear of the head before it dead ends at the head to block mating surface when using the steel gaskets. Problem with this is you cant use the head on the opposite side of the block. Hopefully Tom will comment. I have also experienced oil leaks at the front oil feed hole when using original steel gaskets.

  Tom

[telriv]

If a 1/4" Allen head set screw is used it can be removed. Whenever I install ANY head gaskets I ALWAYS use Hypolar sealant. When I've run into the problem of the front of the head leaking, without sealer, I will normally go back & re-torque the head gaskets. Have NEVER had one that leaked after re-torquing. I will also drill & tap the front oil hole so that if there is TOO much oil going to the rockers you can have a .015"-..020" hole EDM'ed in the set screw as a restriction.

[RivNut]

I'm guilty of hear-say.  I'm just re-iterating what I read on Russ Martin's web sites about using Fel-Pro gaskets.

 

Tom,

 

Do you have any pictures of a head where you plugged the rear oil feed hole in a head?  Did I state that correctly?  I'd also like to hear your opinion of plugging the exhaust crossover that goes through the intake manifold.

 

Thanks,

 

Ed

[Guest skilly65]

Sometimes I just can't win with the duty rosters - I won't be home until the end of February, so cannot strip down & measure until March at the earliest. Bit of a bummer - I have a family friend coming from Florida end of March and he could have carried the pistons out to us.

 

I had also been looking at putting small blanking plates across the exhaust passages to the inlet manifold (we never get snow here, so the temperature is always above zero), plus drilling, tapping & plugging those aft-end oil gallery passages.

 

TonyS.

[telriv]

Plug the exhaust under the carb. NEVER block the ports at the head, unless for racing only. This doesn't apply to 2x4 set-ups as they have no exhaust crossover under the carb. On the street most will hesitate & bog even if the temp. is 100*+ outside. Since the intake manifold is of the divorced type design it runs very COOL in comparison to engines WITHOUT a valley cover. On a running engine, about 1K RPM's, outside temps. in the 90's with 90% humidity, engine at operating temp. on average, point an Infra-Red at the front runners & they will be at about 130*. Air & fuel is passing through the manifold at a pretty good speed actually cooling the intake temps.

   Ed, if you look at where the oil feed holes are you will see exactly what I'm talking about. The holes are approx. 1"-1 1/4" down. Drill with a #7 drill about 3/4" down, use appropriate tap & install the Allen head set screw & slightly tighten.Tap the front while your at it just in case there is TOO MUCH oil going to the rockers at which time you could install the restriction. If the engine is in the vehicle it can still be done. Use grease on the front tap to hold as many metal particles that you can. Then just crank the engine over, disconnect coil wire, until oil comes out. Use a magnet & ALL the metal particles will come out with the oil. On the rear you don't have to worry about medal particles as they have NO WHERE to go. OR, you can cover the area with rags & spray with Brakleen & blow out if that makes anyone fell better. Composite head gaskets are thicker so the .015" stock steel head gasket acts as a restriction. Even using original steel gaskets TOO MUCH oil flows to the rocker assemblies sometimes.

The problem, especially with the composite gaskets is there is NO steel sealing ring to keep the oil from "Weeping" through the layers of gasket material. The oil passages in the block are pretty close to the ends of the block, so this makes matters worse as there is very LITTLE area to seal.

 

   Tony, once the order is in it will NORMALLY take 2-3 weeks for the order to be filled. I could have them drop shipped to wherever if that will help. Make sure ALL the rods are finished to the same length. Normally stock they are about 6.2185" long. if the machinist was good they will NOT be shortened by more than .001" or less.

[telriv]

On another note. I've talked to ALL the head gasket manufactures & NO ONE is interested in installing those little round steel o-rings. So we have needed to find ways around the problem. I think I have come up with a pretty good solution to this problem. I could type for days & still not provide ALL the info nec. for re-building these ole "Nails". I have even been contacted about writing a book. Problem with this is that EVERYONE has there own opinions & no one has died & left me GOD.

[Guest dwhiteside64]

According to Best, their current GraphTite gaskets are composite in construction, not shim steel.

 

Best Gasket RS597G 401-425 Buick Nailhead Full Gasket Set

 

http://www.vintagegasket.com/head-gasket-5597.html

 

http://www.bestgasket.com/about_our_products.asp

[Guest skilly65]

Hi Tom,

 

Just thought I had better let you know I am still intending to get those pistons.

After being at sea since the 19th January, I haven't had a chance to strip down & measure the engine data.

I'm now packing up the house ready for auction, so I probably won't be able to measure the engine before mid-May (I'm back to sea on April 6th).

How can I e-mail you direct?

 

 

 

Cheers

 

Tony Skilton

Auckland

[Guest skilly65]

Incredible - I was looking on TradeMe in NZ (our equivalent of E-Bay) and a chap has a 1959 401 Nailhead engine for sale, and he only lives 10 miles away! I only know of 5 other Nailheads in NZ, total, but this engine is just down the road.

Owner says he has had the engine for a while, and that it was from a low mileage car. Says the heads have never been off, so, if all is as he says, there should be no valve seat recession problems to overcome.

I will inspect the engine later this week and check it still has factory steel head gaskets in place, but in the meantime, can anyone confirm that the 1959 401 heads are a straight fit onto a 1965 425 block?

Asking price for the engine and gearbox is $4,000 (down $1,000 from original price), so I don't want to get it wrong!

 

Cheers

 

Tony Skilton

Auckland

[RivNut]

6 hours ago, skilly65 said:

Incredible - I was looking on TradeMe in NZ (our equivalent of E-Bay) and a chap has a 1959 401 Nailhead engine for sale, and he only lives 10 miles away! I only know of 5 other Nailheads in NZ, total, but this engine is just down the road.

Owner says he has had the engine for a while, and that it was from a low mileage car. Says the heads have never been off, so, if all is as he says, there should be no valve seat recession problems to overcome.

     Valve recession in a nailhead is almost unheard of.  The nickle content of the iron is very high.  Never install hardened seats in nailhead heads!

 

I will inspect the engine later this week and check it still has factory steel head gaskets in place, but in the meantime, can anyone confirm that the 1959 401 heads are a straight fit onto a 1965 425 block?

http://www.teambuick.com/reference/casting_numbers_nailhead.php

http://www.teambuick.com/reference/ident_engine_where.php

http://www.teambuick.com/reference/ident_engine_59-62.php

FYI - The transmission for a 59 will be a Dyanflow, not an ST400

 

 

Quote

 

Cheers

 

Tony Skilton

Auckland

 

Edited March 28, 2016 by RivNut (see edit history)

[telriv]

Yes a DynaFlow would have been behind a '59 "Nail". If he uses the whole engine instead of just the heads there is an adapter made to convert to a 400 Trans. That I have in stock.

 

 

Tom T.

[RivNut]

12 hours ago, skilly65 said:

Incredible - I was looking on TradeMe in NZ (our equivalent of E-Bay) and a chap has a 1959 401 Nailhead engine for sale, and he only lives 10 miles away! I only know of 5 other Nailheads in NZ, total, but this engine is just down the road.

Owner says he has had the engine for a while, and that it was from a low mileage car. Says the heads have never been off, so, if all is as he says, there should be no valve seat recession problems to overcome.

I will inspect the engine later this week and check it still has factory steel head gaskets in place, but in the meantime, can anyone confirm that the 1959 401 heads are a straight fit onto a 1965 425 block?

Asking price for the engine and gearbox is $4,000 (down $1,000 from original price), so I don't want to get it wrong!

 

Cheers

 

Tony Skilton

Auckland

$4,000 (AUS dollars or US dollars) for all. If it's AUS, how does that convert to US dollars?  If it's US Dollars, it seems high to me for an engine that is "unknown" and then your stuck with a dynaflow.  As Tom says, run the entire engine, if it's good, and get the conversion flange to the crank to run the ST400.  If you do that, you'll need a starter that will bolt to the '59 block and reach the ST400 starter ring.  On the Dynaflow, the starter ring is part of the torque converter therefore the starter nose needs to be longer so it can reach the converter.  With the ST400, the starter ring is on the flexplate so the starter nose is shorter.

[Guest skilly65]

Thanks for the replies.

 

We are still going with the new pistons in the 425 block, and using the reconditioned switch-pitch converter & ST400 trans. My only reason for looking at the 1959 401 cu inch engine was to see if the heads are the same, and if they would fit on our 425 block. On our heads, the valve stem tops vary from 0.072" to 0.1105" above the 1.54" target (or, 1.00 mm variation). I see the Buick manual does say the stems can be up to 0.090" above the 1.54" target. With the money being asked for this other engine, I might just fit adjustable pushrods instead.

The NZ$4,000 converts to US$2,700 at today's exchange rate. The 401 is sitting on a purpose-built stand - I don't know if the owner would run it, as it is currently set up with a six-carb manifold on it, and the carbs have no guts in them. He would have to refit the original manifold & Carter AFB to run it.

 

And then there is the chance that we buy the 401 engine, just to get the heads, and then find they have worse valve seat recession than ours do.

 

Back to the house packing!!

 

Cheers

 

Skilly

[telriv]

Skilly,

 

   There are ways around the seat recession problem WITHOUT going with hardened seats.

At one point we can discuss this WITHOUT having to look for replacement heads.

 

 

Tom T.

[Guest skilly65]

Tom,

 

Would it be possible for you to find two rebuildable heads for this '65 425 and then work your magic on them for us?

Magic = near-correct 1.54" valve stem heights (Buick or SBC valves, whatever), plugged rear oil way each side, and then you do the cc'ing measurements for the new pistons to be made.

I will do the remainder of the bores/block measuring here in May when I get back.

Approx. how much would we be looking at? Freight for heads & pistons would be to L.A. only - one of my sons has containers regularly coming from there to NZ.

 

As we had purchased all new valves, springs, valve guides etc, I can box these items up and send to you. However, the guides are for Buick valves, not SBC.

Is it worth the effort?

 

Someone in the US did send me a message offering two 'rebuildable' heads at $70 each, but I cannot now find the message.

 

We have dropped the idea of purchasing the local '401' - it isn't runnable, and the seller has just jacked the price back up to $5,000 again!

 

Cheers

 

Tony S.

skilton.adscan at xtra.co.nz  (NB - no 'e' in 'xtra')

[Guest]

On 12/29/2015 at 7:10 PM, telriv said:

With those Egge pistons they will more than likely be .060"-.065" in the "Hole". From the factory the best I have EVER MEASURED/SEEN is about 9.75-1. This is with a piston in the "Hole" of about .040". RARE. More commonly they are in the "Hole" around .055". Approx. 9.5-1. Using these pistons & the Best gaskets you'll probably end up with around 7.8-8.2-1 compression. Now this throws the "Squish/Quench specs WAY OFF/OUT OF WACK!!!!!. "Nails" seem to run best with no less than .025" & no more than .050". Now we know why one engine runs better than the next. From the factory (at .040" + head gasket of approx. .015" = .055". Just on the outside. With .055" + .015" now = .070". With the set-up you're about to use you could end up with .065" + ,045" = .110". WAY OFF FOR PROPER RUNNING, EFFICIENCY & DETONATION resistance. Because of the "Nails" Pent Roof combustion chamber design they can tolerate a REAL 10.0-1 to 10.25-1 compression ratio using today's fuel. I usually make them 10.0-1 on many of the stock type builds I do. At a ..040" overbore on a 425 the bottom of the block should have been filled with an Epoxy to help keep the cylinder bores from flexing & stabilize the bottom end. This helps the re-build last longer before blow-by becomes an issue & the re-build has to start over, AGAIN!!!! Hopefully you "Sonic" tested the block BEFORE boring. Because of the weight of the reciprocating assembly cylinder wall thickness needs to be approx. .150" thick. Most 401/425's aren't this thick from the factory WITHOUT an overbore.

I get asked/called constantly why the engine they just had re-built doesn't seem to run as well/powerful as the old worn out engine that was removed. NOBODY pays attention to the DETAILS!!!!! Many are trying to re-build the "Nail" using SBC tactics on the CHEAP!!! AIN'T GONNA HAPPEN!!!!!  IF YOU WANT IT TO RUN GOOD, LIKE IT SHOULD IT COSTS$$$$ TO PAY ATTENTION TO THE DETAILS!!!!

About the valve seat recession. One of the things I normally do in this situation is to use SBC valves. I take 1.940" intakes & cut them down to 1.900". Use 1.540" or 1.600" exhausts & cut them down to 1.520". This now puts them at a new seating area to re-finish the valve seats. This will "Repair" the proper valve heights. NEVER try to install hardened seats. Many/Most times you will cut into water. Especially on the intakes. If they don't leak today give them 6 months. I would be willing to bet they will start!!! You need to get valves that the total length is about factory "Nail" length. So they need to be cut to length also. Make sure the tops of the valves are hardened deep enough & can have AT LEAST .100" removed from the tips. They will be required to use 11/32" valve guides. I've had them made just for our beloved "Nails". DON'T EVER TRY LINING THE GUIDES. Because of the EXTREME side force put on the guides because of the short, stubby rocker arms (Much amplified by a higher than normal lift cam) the liners usually fall out of place. I don't care what you or the machinist does, they WILL dislodge themselves.

Using SBC valves now gives you a Pandora box full of options as far as springs, retainers, valve locks, etc.

I realize it's more than likely TOO LATE in your situation, unless you want to start over.

I could type with one finger for days & not give enough INFO.

 

 

Tom T.

Thanx for all the excellently researched info you provide. I posted that the later aluminum rocker assemblies with 1.6 ratio, which I read allows for greater lift on my 55-56 322" without other modifications, would put undue stress on the valve train geometry. What is your advice as to the viability and possible increase in cylinder filling this might provide?

[telriv]

As far as I'm concerned there is NO problem doing this. It's usually good for a 10-15HP increase. It will NOT put any undue stress on Any components. If the car has a stock cam there's also NO issues with valve to piston clearances.

 

 

Tom T.