Is there any advantage to using bigger cc heads. Say if i have a 64 cc head with 10 cr. and say if i use 76 cc heads with 10cr. I would think it would help unshroud the valves for better flow but I want other opinions. Thanks.

 

If you decked the block, you may need larger CC's to keep the CR down to an acceptabe range.

Best to have the burn in the combustion chamber as opposed to the bore, for best efficiency.

I/e better to deck the block and run flattops and larger CC, than leave standard deck and run domed pistons and smaller CC heads to achieve your CR.

 

Dome pistons can limit the flame travel inside the combustion chamber.

The dome intrudes into the chamber and literally separate it into two halves. There's only one spark plug. The flame has to travel up, and over the piston to the other side. It's called propagation. It basically enlarges the area the flame has to travel in a given time.

A 'd' shaped dished piston with a smaller head chamber is the way to go. It forms a nice little "pocket" and condenses the air/fuel mixture into a tighter area, making it easier for the flame to burn more fuel.

 

you'd have to look at the whole package but usually there is no reason or advantage to running larger chamber heads. to me the ideal set up would be zero deck block, dished pistons, and small chamber heads.

 

It depends on the specific heads and their chamber design; but usually, there's not alot of difference in valve shrouding.

About the only reason to run large-chamber heads is to keep the compression down for use with a large engine, or when using a blower or something.