I need EVERYONES opinion on comparing two engines!

[Guest]

Ok, lets say i have a stock 70 350 and a stock 76 455. which engine has more power from the factory? which engine would you build (mildley, headers, intake, cam)and on a budget, like most of us. which would be cheaper to build, in this situation? please put your two cents in! thank you

[Guest]

If i had a choice between these two engines i would go with the 350, being in that situation.

[Guest]

My $o.o2 says go with the 455. In the long run the high octane fuel needed for the 350 is gonna kill your wallet in time. You can still do a lot with a low compression 455 if you want a torque monster and the cheap gas will also save you money. The parts I have priced out there ain't much diff in cost between the 2. The 455 stuff is more readily available though.

[Guest]

First of all he`s not talking about doing alot to the engines.(mildley) and second of all, I wouldn`t be worried about "octane", I would be worried about which has more power. My opinion would be the 350, considering it had more power from the factory. Remember he`s talking minor upgrading to these motors.

[willie]

I totally agre with hot rod!

[Guest]

Ok here we go. According to the specs I got. There were 3 350ci buick motors in 70 #1 2bbl 260 hp@ 4600rpm & 360ft/lb torque @2600 rpm 9.0:1 comp. #2 4bbl 350ci 285 hp @4600 rpm 375 lb/ft @3200 rpm 10.25:1 comp. #3 4bbl 315 hp @4800 rpm 410 lb/ft @3200 rpm 10.25:1 comp. These are advertised ratings measured as BHP (@the flywheel). 76 455 4bbl 205 hp @3800 rpm 345 lb/ft @2000 rpm 7.9:1 comp. After 1972 measurements were taken at the rear of the transmission with all accessories installed and operating. These were called SAE net HP ratings. If you take these factors into consideration I'd bet you would find that the 76 455 would come very close to being the equal of the best 350 of 1970 if you measured HP in the exact same fashion. I'd also bet most of the 70 350's were of the midgrade variety. Yes No Maybe?

[Guest]

I'd take the 455. You can run water through it with 8:1 comp. A quick intake change will help it breath better. It's within 10% high or low powerwise of the 350, but it would never need to see the high side of 4500. Torque folks...that's what rules the world. Cats pulling 50' 80,000 lb trailers don't have 800HP, they have 800 FOOT POUNDS of torque. Torque is a direct function of cubic inches. If anybody doubts that cubic inches rule....look at Lawrence Conley. Tweaked was a 272 CID V-6 now it's a 44something big block chebby.<P>------------------<BR>Drew Schofield<BR>83 Regal<BR>64 Skylark Convertible<BR>www.angelfire/tn/page4drew/regal.html<BR>droopie@midsouth.rr.com<BR>

[Guest]

Well I posted the original question way back when, and the specs for the 70 are accurate The engine I have is the 10.25 hc 315hp according to the manual and the engine code stamped on the block and yes I have heard about the change in measurements of HP I guess that is why I started looking. and yes I am on a budget and I need to cheange the rear gears. 2.76 are not helping. so if I find a donor of unknown condition 250 - 500 then need to redo it just to get it to stock or slightly modified will it be ahead of doing the upgrade modifications to the 350 for the same total $. also I want this thing to go I want to feel it. So if I spend my money on the 350 and I can't feel it I will be disapointed. and will eventually have to spend more to get the 455 but if I spend the budgeted amount on the 455 and don't get the feeling then I will really be pissed.

[Guest]

I happen to have a '69 'Lark with 350-4 (10.25:1). I am going to keep the 350 and add a cam and intake. But I must also mention that it is the original engine and part of my consideration is keeping the car original.<P>Now if I my main concern were building a decent street machine or if I had bought a car with no motor, I would get the 455 and buy a cam, intake and headers. I'd be way ahead of the 350 even with the low compression of the 455.<P>Ron*

[Guest]

i would always go with the larger mtor. you wil not beat the torque of the 455. and in the futre if you want more power you will love the potential of the 455. it will beat the 350 in performance. do not think of only the short term. if you can only do the mods that you describe, fine. in the future if you want you can fully rebuild the motor. if you use the 455, after a mild rebuild, the motor will make 350 hp and 500 lbs of torque with a stock type 1970 rebuild. what are you going to have to do to that 350 to put up these numbers? <P>always use the largest motor possible for perfomance applications. if you do not care about performance than build what you want.<P>john

[Guest]

A simple answer to a simple question applies here as well as any other place.<P>The only replacement for cubic inches is cubic dollars.<P>Give me the 455.

[Guest]

I have questions...I have a 70 Wildcat that was originally a 455 10.5:1...The woman I bought it from blew the orig engine and replaced it with a 430 (I'm guessing 9.5:1).<BR>I came up with a 455 out of a 72 Riviera and I want to put this in..I love driving this car on the highway and I really like scaring the Hondas at traffic lites (They don't think boats can move!) I agree with torque and this car really has it. My questions are:<BR>1) I was told 10.5:1 was too much today if I'm planing on lots of highway miles (and I am). Comments?<BR>2) I am looking thru an old issue of PAW and they list 4 different cams..#1 being stock and #4 being "the engine barely runs"..I was thinking about going with #2..Comments?<BR>3) When you are talking about intake manifold are you talking about a different one or working on the old?<BR>4) I can't find exhaust headers anywhere..I know they are the best bang for the buck because I've done it on another car..I don't want to have to do any body mods to make them fit...Comments?<BR>5) Someone said I can put a 74 electronic distibutor in place of the mechanical point style..True?<P>Thanks for any inputs? I really love this car<BR>and she loves me..

[Guest]

i'd like to here more about putting a electronic distributer in place of points i have a Holley Annihilator ign. and was wondering which would be better, to use it with points with different springs or a distributer from a 74 or newer?

[Guest]

let me respond to the guy with the 70 wildcat. 10.5:1 is not too much for highway miles. my 94 Z-28 has 10.5:1 and i drive it long distances all the time. you just have to use "super" (93 octane) gas.<P>also i am not sure of the cam you are talking about but the lower compression in the 72 455 (8.5:1) will require a cam choice that takes this into consideration. i would call a few engine guys to get their opinion on this before you buy a cam. or if you change the compression to 10:1 or 10.5:1 than that increases the cams you have to choose from.<P>also the GM HEI found in the later 455s will fit into the 72 455. i have done it in the past. <P>john<P>anyway, that is my thoughts.

[The Old Guy]

The best HEI is the one from the 350 as it has a better advance curve than the 455 HEI. If you change the gear you are in business. The 350 has 14 tooth and the 455 has a 13 tooth,but they are interchangBLE

[Guest]

Think of the comparison this way:<P>Torque is what makes a car accelerate, horsepower is nothing more than top end. For street use, tire smoking and impressive launch characteristics, torque is what you want.<P>In order for a 350 to make equal torque to the 455, even with the low compression, some more than 'mild' work will likely be required. A large, stock engine will always be more reliable than a modifed smaller one.<P>10.5 to 1 will be a royal pain in the ass for you guys. Here in Canada we have better quality gasoline, and we can run upto 11:1 sometimes on premium. In the States, your gasoline will usually start giving problems by 10:1 or so. This is why the magazine editors always build their projects to 9.5:1 or so. Any more is asking for trouble. <P>The reason the Z28 runs compression that high is for two reasons:<P>1) Superior cylinder head design that is less prone to pinging - especially if its aluminum castings<P>2) The timing is computer controlled, and if the engine starts pinging the computer automatically retards the timing to suit.<P>I had a PAW catalog here, but my brother has borrowed it and not returned it.<BR>Camshaft #2 is usually still ok with stock convertor and low compression. It should specify exactly what range it wants, including gears, convertor, compression, and carb size. If in doubt, call the people on their tech line.<P>Personally, I'd use the 455 with a mild cam and the Edelbrock performer (or similar dual plane design). Headers would be a plus, but a good set of cast manifolds can be prepped or even extrude-honed if they are unavailable.<BR> Either that, or build your own.<P>Derek<BR><P>------------------<BR>1968 "Canadian" Pontiac Beaumont<BR>1988 Buick LeSabre T-Type<BR>

[YellowLark]

On the CR, I think that 10.5:1 is too high for today's gasoline in a pre-computer car.<P>My '66 340 has 10.25:1 and it pings under acceleration even with Sunoco 94.<P>I have to go an octane booster mix giving at least 96 before the pinging subsides. <P>A CR over 9.5:1 is no sweat for a modern computerized car, but a real hassle for your 1970 model.<P><P>------------------<BR>

[Guest]

I believe there is no substitute for torque. Period. The 455 will be so much more fun stoplight-to-stoplight! My vote is to go with a 455, even a late model, any day. Having said that...<P>As far as compression is concerned: a good rule of thumb is to take the compression ratio and move the decimal point. Ex: 9.5:1 should use 95 octane fuel on an older motor without electronics. On a small block you may be able to get away with a higher c.r. than with a big block (something to do with swept area I think.) Head gasket thickness, deck height, combustion chamber shape and volume, &c. all contribute to the ability to run on pump gas without pings. A great article on the subject was in the July 2000 Car Craft.<P>To the Wildcat owner: unless the engine has been rebuilt, the stock compression in a 430 was 10.25:1 for all three years of that engine's production.<P>On the subject of cam choices that "riv1973" touched on: big cams bleed cylinder pressure. If you don't have a lot of cylinder pressure to begin with (i.e. 8.5:1) your cam choices are indeed limited. However, as Derek points out, 9.5:1 is about the top practical c/r for use in this day and age when we are limited to pump gas rated at 92 or 93 octane.<P>As far as after market performance parts go, I highly recommend checking out both Poston and T/A Enterprises for cams, intake manifolds, headers, and mandrel bent exhaust systems. Both of these vendors are Buick experts/specialists and have years of experience building and tuning Buick engines.<P>One final thing: the February 2000 Car Craft has a great article covering a mild build of a Buick 350 should you decide on that motor instead of the 455. They also explain rated compression vs. actual compression as it relates directly to the Buick 350.<P>The Car Craft articles should be available at your local library and I humbly suggest reading them... they are a wealth of information!<P>Matthew<BR>

[Guest]

I don't know where I got the idea that the 430 had a cr of 9.5:1 but I will take your word for the 10.25:1 because of the unbelievable torque this car has and I LIKE IT!!! Now I'm in a delima because I've never had pinging..She had no idea what was done to the 430 (if anything)...I would leave the 430 alone but oil is not getting to the rt rear rockers and she was using the car for a tow truck to move from Tex to here<BR>(Colo, uphill all the way).<BR>The 72 455 is in excellent shape but it's 8.5:1...I will check out Poston,T/A, & Car Craft....Thanks for all the inputs.

[Guest]

which engine, i don't know. what are you going to do with the engine you pick is probably more important. is it going to be put in a lawnmower or 18 wheeler or drag car or formula one car? take your pick first, then you can ask for which motor is better. so your present question is really not a question till you answer what it is going to reside in. you wound everybody up for nothing.

[Guest]

I have a 1970 wildcat and am planning on discussing with Greg Gesssler on maybe doing me over a set of stock exhaust manifolds to flow much better.He is a member of the GS club and was doing this kind of work a few years back .

[Guest]

It depends what your goals are. If it is primarily for the street the 455 is more fun. If you are trying for a lower et, then the 350 is better if the car is sufficiently light, otherwise the 455 gets my nod. I can not tell what constitutes 'sufficiently light', without more facts like gearing, and traction. Iknow this didn't answer the question, but everyone has an opinion, and debating about it won't change many minds. I like the 455 and the chevy 350, but I am not very fond of the buick 350, so it's not even a question for myself.