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Re: ? on head porting Posted by John Williams [Email] (#1982) [Profile/Gallery] (more from John Williams) on Wed, 13 Dec 2006 14:58:52 In Reply to: Re: ? on head porting, Dean, Wed, 13 Dec 2006 13:55:07 Members do not see ads below this line. - Help Keep This Site Online - Signup |
There is a theory that if you leave the exhaust port slightly smaller than the exhaust manifold, it will work as a dam to help with the pulse tuning and the effect with a larger exhaust port with it matched is that the exhaust gasses can go back into the head in some cases on throttle plate closing or deceleration and maybe some other situations? Since I am using the stock manifold that is also ported and polished, I went ahead and port matched the exhaust side as well as the intake side. Some say to port match it, some say to leave the exhaust side slightly smaller so the dam effect and the pulse tuning will remain intact. Not sure which is better, but more seemed to port match than leave smaller. If you had two heads to try this on you might be able to find out which one is better. I would bet you could not measure the difference in performance once installed on the car and testing acceleration... My 2 cents, John
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