Quote:
Originally Posted by oldskool
http://www.classracerinfo.com/Engine...9&MAKE=Pontiac
The info on Class Racer Info shows the max compression to be 12.49. Pontiac never advertised a '68 D-port 400 with near that much compression. Don't take a genius to figure out that the 65cc number is NOT the size of the chamber, from the factory. The deck height is listed at .000. Everybody knows that the Pontiac engines did not have zero deck height. The pistons were in the hole, some say, over .020. BUT, NHRA will ALLOW the racer to have zero deck height.
I have no idea where you got that info. The only '68 up chambers that I've seen advertised near that small are on the 350HO heads. The Class Racer Info site shows the NHRA min chamber size to be 61cc, which will give the engine much more compression than they had from the factory.
http://www.classracerinfo.com/Engine...8&MAKE=Pontiac
So, you're saying that PMD purposely gave NHRA bad incorrect info that would increase performance & NHRA never questioned or checked it ??? 
That don't sound reasonable to me. AND, the way many Stock racers are, I figure that by now some racer of a different brand would have complained to NHRA & got the legal numbers changed.
But hey, what do I know. 
|
It seem you do not understand how increasing bore and stroke the legal amounts (engines ci's) while holding the other specs constant will increase CR to be higher than the stock engines CR.
The 12.49:1 is nothing more than Dwight doing the math for you.
Stan