231 Head and Intake Porting

[BBTurbo]

Is it worth pulling the heads off and porting them? What size is the valves in this motor? How about porting the intake? I would like to squeeze the most out of this motor. Will the turbo benefit from this modifications? Also, I have heard that the 3.8 is a 305 with two cylinders cut off. Is this true? Thanks in advance for everyones input.

 

[anti-chevy]

It's always worth porting the intake and heads, if you can afford it.
The valve sizes are 1.710 in. and 1.500 ex.
A 231 buick is kind of like a 350 buick, destroked, w/ 2 of the cylinders cut off.

 

[pat83t]

That is the stock size, but you can have it machined to accept 1.80 intake and 1.60 exhaust valves. I had it done on mine. Porting of the heads made a noticable difference also.

 

[fc227]

Porting the heads real woke my engine up.

 

[bruce]

Originally posted by BBTurbo
Is it worth pulling the heads off and porting them? What size is the valves in this motor? How about porting the intake? I would like to squeeze the most out of this motor. Will the turbo benefit from this modifications? Also, I have heard that the 3.8 is a 305 with two cylinders cut off. Is this true? Thanks in advance for everyones input.

Just a fine stone, and smooth out the combustion chambers. The edge where the head gasket surface meets the actual camber is critical. You want a really small radius to just make sure there is no real edge for a hot spot to form. Then a little pocket porting.

Easy way to power is adding, boost and the common limit to that is detonation, so you want to work on preventing detonation.