Which Head?

[poorboychevelle]

Flat out, which 4A heads flow the best. Im looking to probably build a turbo'd motor, and I'd like to know which heads will let me cram the most air in there the easiest. 20V? Red top, blue top, big port, small port?

[REN69]

Do you even know what everything means? Blue tops only came in big ports while red tops came in both big and small port, 20Vs came in silver and black top.. confused yet?

I would say first the 4AGZE (which you didn't mention) next would be the redtop bigport.

Both 20Vs have been successfuly turbo'd before, the Silver top seems to be the choice out of the two.

[punter]

Blacktop 20v, proven to be the best head for forced induction.

You will need heavier valve springs if you're pushing more than about 25psi down it.

[Gsolo]

I may be wrong but i believe the silvertop head is better flow because the valves aren't shrouded. IIRC the blacktop head valves are slightly shrouded in the attempt to boost comp. can't find any pics of the combustion chambers...so i'm probably wrong

And heres a pic of head flow between small port 16v and silver 20v.....pic is from billzilla.org hope no one thinks i'm stealing it