So looking for help as i am putting together a 1967 283 motor bored 30 over. Using power pack heads 8884520 that I think are 60CC by what I found on the net. running a 3 duece carb on top. So what head gasket should I be going for the heads .All the part houses want to sell me the generic sbc gasket that is really more for a 350 with a 4.125 bore and are kinda thick . I have seen articles on here talking about using something closer to the 3.9 bore and thinner like .15 thick. 10105117 maybe or SCE511961. The heads have not been milled , Thoughts
Call this number 1 800 *** 3030 tell them you need felpro gaskets for your particular motor. *** PM for these 3 numbers I don't like to spam on the board.
Before Covid they still could be found. I just looked, but as much time as I've been looking I should have seen something pop up but no. Not to say they are not still out there. An easy one to find but I don't know if you'd settle for? https://www.summitracing.com/parts/fel-1094
Are the wrist pins offset on small block Shivel-laz........like on SBF? If so, free HP for the tak'in 6sally6
Rotate the pistons 180* on the connecting rods to gain a better angle between the wrist pin and the crank pin. Common practice on building SBF engines to pick up a few FREE HP....at the cost of a little noise on a cold start up.(not noticeable at all with headers.and 60+ years of age!) 6sally6
Speedway had steel head gasket sets , like original equipment. Thin and correct size .any 4” sbc gasket set will work . Dont use 305 , obviously.
There has been some internet slag going on over that subject. Uncle Tony made the claim, the Hot Rod guys said it was false and kind of insulted him & challenged him to prove it, he fired back at them with his own challenge. I don't think the claim was ever substantiated, was supposedly something advised by Direct Connection at one time. It's all on youtube.
Is Performance Auto warehouse PAW still open ? I can only remember 4” bore steel shim gaskets being used on all but the 305 262,265 and 400 . The use on 283 will not do any neg harm or comp increase . The resulting area quickly fills with carbon.
I don’t think it’s considered spam to say “call Joe at his shop, here’s the number”. Especially when trying to get a guy something he wants/needs.
The late Joe Sherman a pro engine builder/drag racer made the claim in some of his builds in Hot Rod Popular Hot Rodding that a 7% increase in HP (in a SBF) was realized when rotating the pistons 180*. Roger Huntington automotive editor for Hot Rod made the claim back in the mid 60's when building/racing/dynoing SBFs.(289's) Local engine machinists here told me the same thing. I don't know, but when that many "so-called" experts make the claim (and rotating the piston does sound logical) I tend to believe it! I did it on my SBF builds but......with other mods it would be hard to identify just HOW much of an increase it netted. I know it hasn't had any negative effects in my case. I was just passing along some information I thought would be helpful. 6sally6
Maybe, I really can't say either way. Here's what the hot rod guys say (note, I'm not a big fan of these guys, but they know more about high performance engines than I do):
When you put the pistons on backward it changes rod angle. It does not create more power it frees up to power that is already at hand. Piston pins are not centered. it works better in some engines then it does in others. Now here is the rub, it is very hard on the piston skirts, normally is is done with forged pistons and until everything warms up and swells it sounds like you got serious piston slap. Now I am not a famous guy but I have some experience with things that go faster than they should. So you can take it or leave it.
Interesting lil vid clip! I'm not a big argue(er)...is that a word?.....I DO know that after market pistons I've bought DO HAVE an off set so they are full -of-it there! Keith Black Hyperutecnic(sp) ones any way. The "side loading" fried-burger mentioned is a non issue according to Sherman...Huntington...ME...Bill Fisk... and other machinists I've talked to. I do agree with him in one respect......anyone is free to disagree or not with me about it. (I would also love to see a back-to-back dyno test to measure amount (If any) of power increase.) 6sally6
I seem to remember this was done to the 57 Chevrolet drag car (Project X?) an ongoing progression of changes back in the mid 60s maybe in Hot Rod, Car Craft? Also seem to remember that reversing the pistons raised the existing maximum HP to a higher RPM level in the era of screaming small block Chevys But then again, I'm old and maybe not.
Has anybody watched the engine masters episode that explores the piston swap theory? It was a waste of time.
If the pistons have the stock compression height,they should be about .020 down at TDC.. with a shim gasket of about .022 thickness this gives an effective squish of about .042. Squish is essential on modern gas for detonation resistance with a faster burn . Better throttle response and fuel mileage...
A head gasket question devolves into swapping the pistons around? It truly is a strange world. I like the Cometic gaskets. Find one with a close bore size and you should be good to go. We could drop into the rabbit hole where we calculate actual cylinder head CC, fixed compression ratio, etc. but on a 283 with Tri-power, I wouldn't even bother. You're just looking for a decent head gasket that won't leak, it's not rocket science and the compression ratio is probably shit to begin with. Don't over think it.
If one's goal is to extract every horsepower possible, you're not likely expecting the engine to last 100,000+. A professional racer will be satisfied if the engine lasts through the event.
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