how is it?

 

i woudnt change anything on the head. it has been found that the head can flow efficiently 600+ hp. i would have it done to stock specs, maybe polish if there are burrs in the chambers anywhere, but i wouldnt change a thing on it otherwise.

the only reason to do dual valve springs and ti retainers is to combat valve float. and you wont get that even revving to 8500 on an ap2. depending on how much it will cost to get head rebuilt, i would look into a used one.

 

Stock size is fine. Although my machinist did say that the most restricting part of out head is the valve size. Intake and exhaust runners flow plenty.

 

Stock size will be great for much more power than you will be able to make with a turbo twice as big.

 

Laskey or Inline both will get you a good price

I believe the following list are the correct valves for or head and the match an RSX with +1mm valves, you will need to double check the materials though. If you go Supertech then you will want the run the Inconnel on the exhaust side and the regular on the intake at minimum. The Ferrea's are what Inline uses and consequently what I am running.

Head Diameter: 36.00 mm (stk)
Stem Diameter: 5.48 mm
Length: 109.85 mm

Head Diameter: 31 mm (stk)
Stem Diameter: 5.45 mm
Length: 108.8 mm

Supertech

 

It is better to have increased valve lift then size.


Yes size will increase flow however there is one major thing that is constantly over looked.



Intake velocity.........................