cnc nissan cylinder heads

[jr_ss]

Originally Posted by godzilla_753

dunno if this is a pertinent question but I always wondered why the f20c's and evo 4g63's made so much power from factory, does it have to do with head flow as Ive been assuming? I know STOCK ENGINE (this means head as well), s2000s are putting down over 500 WHP, while EVO's are putting down over 300 wheel which puts em at close to 400 at the engine with stock turbos. Ive always thought SR's were a bit lackluster, at least in BPU form

It's because their heads have far more advance design than the Sr's. F20 and 4g's heads flow deep into the 200CFM's and even into the low 300CFM's on their intake sides. Compare that to the DE/DET heads that only flow low 200CFM's on the intake side. The VE head is much closer to the F20/4g heads in stock form. Another key feature is the fact that their valves are almost vertical to the cylinder, making room for some serious lift and duration.

From my take on things and some research, I've found that the VE heads can get into the mid to high 300cfm's. Obviously, with any port work it takes a good knowledge of how heads flow and what it is going to be setup for. A turbo motor won't necessarily benefit as much as an NA head would with a crazy amount of work and vice versus.

I think the exhaust side of a head needs more work than the intake side on a turbo motor. Where as NA would most likely benefit more from intake. Either there are a lot of variables that go into making a good flowing head. Just porting the shit out of it, isn't the best way to go about it.