Although USDM STI heads have higher volume than others Spec C heads ouflow all others due to better design:



JIM

 

I have been looking for that info for ages! Thanks Jim

My ported heads have had their combustion chambers tweeked and each chamber currently has a volume of 56cc, only 1cc off the standard EJ257 heads. Although with the gaskets I'm running I worked out that my CR would be 8.6:1

 

i dont see any flow information in that list Jim?

 

Tim,

Are you sure someones taken circa 10cc's out of the chambers. Thats a hell of a lot.

Mark.

 

Ahh...runs off to check...

 

Damn, can't find the details now

46cc standard wasn't it on Sti 4 and 49 cc on Sti 5, pretty sure Steve got it into the 50s, will have to check with him...

 

At least this is what have been told John from local Subaru service (due to better design), may be I am wrong though!