list of Oem heads flow #s and CC sizes

[Shiozaki]

trying to work out which heads will fit on a 2.8 and what my internals need to look like to reach a boost friendly CR, info is hard to find...

[sharkey]

i dont have that info, maybe check out the wot-tech.com store, they have some flow numbers listed.

is your engine a gen 1 (iron head) or gen 2 (aluminum head)?

[Guest]

Any heads from 2.8 to 3400 will fit (3.4 DOHC excluded).

Everyone will recommend the 3400 heads (also LARGE port 3100, which are essentially the same heads), because they will fit your bore size, and flow the best as far as OEM/junk yard heads go.

"Boost friendly CR" is subjective. Years ago EVERYONE would have said somewhere around 8.0:1 is what you wanted, a few years later with better engine management, 9.0 or so is what would be recommended, now, pretty much anything goes, based on so many variables.

Personally I've run as high as 9.8:1 with about 12 PSIG so far, stock LX9, with a cam swap. My new engine will be between 10 and 10.2:1 and will run as much boost as it takes to hit the power number I want, which really shouldn't be that much.

[Shiozaki]

the CC of the different heads is whats really tripping me up ive seen 52/53 and 28cc, casting numbers would help.

[sharkey]

on the main page of this site on the left side near the top there is a compression calculator, the specs for the various engines is listed in there. casting numbers i cant help you with, its sort of irrelevant, there wernt different designs of heads for each generation of engine, aside from the small port 3100 vs the large port 3100/3400 for the gen 3 heads.

the cast iron heads are 48.5cc and use a flat top piston. the gen 2 2.8l aluminum heads are 26.4cc with a 21.2cc dished piston.

[Guest]

I have heard anywhere from 48cc to 52 cc in the iron heads. Gen 2 aluminum were like 26ish.

gen 3 3400 might be around 32. I think 3900 was 34cc or so..

Wot tech Ben measured them all.

[woody90gtz]

I just measured the 2004 3400 heads today and they are 29cc with a 28cc dish piston.