porting 4v heads > any help??? please

[jeremy canter]

DOES ANYONE HAVE PIC"S OR A THREAD on porting 4v Cobra heads > ANYTHING !!!!! >
I picked up a second set of 96-98 cobra heads and I'm planning on test porting the CRAP out of them but I want to know what ANYONE has done to there heads
I plan on cutting the center wall out of the intake passage so the b-heads intake passage looks more like a c-head does > and Ideas tips any thing you think of or have read > SPEAK UP !!!!!!

 

[Mr. Rustypwnz]

whoa there killer, the intake ports dont need all that work to flow well, a simple port (small porting) mostly in the bowls, and a good valve job will pick up alot.. what your going to do is kill the velocity and youll have to turn 5000rpm before it comes alive, not good, i would just get a set of c heads off a continental and port those, that way you can have a little better torque as well..

 

[Kilgore Trout]

There is a user named Posi on Modular Fords that has been into porting 4V intakes, blowers, and heads for quite some time and he is usually pretty open to knowledge sharing. I am sure he could give you some good advice...

 

[billfisher]

ll those heads need is the primary short side radiused, frpp stainless intake valves, bowls blended, 250 grit sanding, the exhausts reshaped where each valve has its runner blended, floors left alone, divider walls altered. if you port them too much they are ruined very quickly. the secondaries only need sand rolled. remove as little as possible. blend the primaries where they transition from square to round. get them flow benched and velocity checked and "FIX" the areas as needed. be conservative. remove the guid in the secondary where it extends into the port roof.

with stock valves you can expect simple bowl work, and runner smoothing to add 30 cfm(260ish) cfm. the FRPPvalves will add about 12cfm at low lift.

they typically flow 233 stock at .500. properly ported they flow 340 or more. but low end WILL suffer if they are ported.

most folks get 380 rwhp with a short runner intake and big cams. with all of the bolt-ons.

 

[jeremy canter]

sweet > I'm looking to push 400 hp out of my motor thanks for the headup> I'll keep diggin info if you think of anything else > LET ME KNOW !!! > I need it > I GOT A VETTE THAT NEEDS A BUTT KICKIN