Thread: GTiR 54C head flow data

its always important how air flows NA or Turbo but volume and velocity is very important. Personally ive always noticed to make more power from Low port engines

One thing you need to remember is that the air is ALWAYS being FORCED into the cylinder. the piston does not "suck" the air in, the piston creates a low pressure in the cylinder and the atmospheric pressure is higher and thus moves into the cylinder. the more pressure differential there is, the faster the air moves into the cylinder as fast as it is possible... AKA limited by the cylinder head flow.

The high port head casting is just a modified version of the 54C head that was originally designed that way for the solid lifter setup for the BTCC and JTCC cars. Nissan just modified it for HYD lifters for normal every day use.

High ports are more available and cheaper. The high port also has a larger port cross sectional area compared to the flow of the port VS the low port head which flows more with a smaller port thus more velocity as well....

Sawwweeet

Thanks for the post Snickers. I didn't know actual head flow numbers from either low port or high port heads. Guess I'll stick with the lowport head, and clean it up a bit more. All that's left is valve guides, and portwork. Maybe I'll toss the STD supertech's for some oversized...

Hey snickers, what would you say most stock SR16 heads flow at stock? Would the flow be comparable to, say, a 2zzgte toyota, or a B18C?

Most B16 heads flow around 240-245 stock. a b18c1 is a little more, havent flowed a Type R head though.

I do have 2 B16 heads that I have gotten to flow 298 @ .500" lift....

THere was a lowport head in the S14's??? That is news to me. I thought all RWD Det's came with the highport head.

EDIT: I just checked wikipedia. Image of an s14 and yes it does have a lowport manifold. I just learned something new. LOL. Well Makes me feel better about my 94 motor.

How did I miss this?

Thanks for the great info Charles!

Maybe this should be moved to the GTi-R section (or General SR20)? There's no way it belongs in "All Motor". =]

I'll need to find this later I'm sure, just making it easier to find.

Just as long as i know where to find it....

If i got info i can share, then i'd be happy to share it!

Charles, once the work is done you can show numbers from my head as an example of how much improvement can be achieved with a killer valve grind and some port work on a GTiR head.

Cheers,