View Full Version : Head porting ?

04-15-2007, 02:04 PM
Is it necessary to port the exhaust ports on the heads? I started gasket matching mine is it a bad idea? or a help? looks like the ports on the exhaust manifolds are MUCH larger than the ones on the heads so......

04-15-2007, 03:32 PM
There is supposed to be a lip on the Head exhaust ports to prevent exhaust gasses from feeding back into the heads. But as far as porting, im not really sure.

- Dan

04-16-2007, 01:48 AM
So leave the lip?????

04-16-2007, 12:13 PM
Does anyone know if this lip should be left????

04-16-2007, 12:17 PM
do not port match the exhaust side just smooth and polish it up. do a search there are tons of threads on head porting. This is also an informative link


04-16-2007, 12:56 PM
what if i took the lip off and gasket matched it? would this be a huge problem? don

04-16-2007, 01:45 PM
A lip can be good for anti-reversion. If you are staying with stock manifold, I would leave the port size alone and concentrate your efforts on making them smooth and straight. The problem is the firing order and reversion is a problem on most manifold designs. Longer primaries will help but unless you are going to build your own bundle-of-snakes 6-3-1 (1&5 2&6 3&4, each primary 180' out) exhaust, reversion is a concern.

Also, the further you port the stock exhaust manifold primaries, the further you can open up the exhaust port and still have the same degree on anti-reversion.


04-16-2007, 04:52 PM
well i already ported it to match, so ill have to see if it helps or not. ill let you know once the car is together and running. don

04-16-2007, 05:01 PM
here's a good head porting thread for u members :