Thread: Pontiacs
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Old 09-08-2021, 04:33 PM   #68
oldskool
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Default Re: Pontiacs

Quote:
Originally Posted by Stan Weiss View Post
Doesn't NHRA like other engine specs use the Chamber Volume supplied by Pontiac?



Stan
No !

Here's just one good example. It has long been published & is commonly accepted that the '68 400 D-ports had aprox 72cc chambers. Some say that many actually measured a little bigger. NHRA allows 65cc chambers. So, that's roughly a 10% reduction that NHRA allows. Obviously, that will increase compression & power.

http://www.classracerinfo.com/Engine...9&MAKE=Pontiac

Obviously, they didn't do that for the '75-'76 Pontiac 455.

Compression is obviously a factor that must be considered in determining the power potential & thus the competitive possibilities of a Stock/SS engine. The power potential must then be weighed against the current NHRA hp factor of the engine, to decide if it might be a good engine to use, or not.

Last edited by oldskool; 09-08-2021 at 04:55 PM.
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