Cylinder heads

[Zer0PSI]

I'm starting out with a N/A 2.3 and adding the turbo with forged internals. Can I make just as much power with the N/A cylinder head as the turbo head?? And if so would the "D" port or oval port head be better??

[Davis]

the NA head do just as well as the turbo head and wont be cracked like 80% of the turbo heads out there. when you rebuild the head just make sure you get hardened exhaust valve seat inserts put in so that the seats dont burn out. also round/smooth off the protrusion between the valves (in the combustion chamber) to reduce the tendency to ping. unless you are going for over 350 horsepower, i think it doesnt really matter what head you use.

(p.s. this is what i did, i went the same route as you. looking back it would have probably been cheaper to just swap in a turbo motor.)

[pony-up]

There is a little difference between an N/A head and a turbo head. I have one of each from the early '80s, w/ hydraulic flat-tappets. The turbo head has some circular machine cuts around the valves that de-shroud them, a little. I suppose it would provide a little better flow at low-lift. The shape of the combustion chamber is a little different, too.

[shadetree]

Use the D shaped heads. They flow a little better. You want the head to have a D shaped(open chamber) combustion chamber also. The heart shaped combustion chamber(closed chamber) has a higher compression ratio, and the engine will have detonation problems at higher boost levels. You can grind out the combistion chamber to lower the compression ratio if you can't find ones with the D shape. shady