Piston perfromance
 

Ok, so I am home and not at Indy racing so my mind starts thinking.....

How much performance difference is there between "flat with notches pistons VS a dish piston"? All other things being equal, valve, cam, same carb etc...

Doubt anyone has back to back this but someone has to be smart enough to figure this out.

P.S. the last thread on FI vs CARB was great.

Re: Piston perfromance
 

Flat pistons should give a better quench and more efficient burn. There is a trend toward d-shaped dishes for big inch pump gas engines, to keep a good quench and still lower compression.

Re: Piston perfromance
 

I don't think you can look at an A to B comparison for piston top for performance.

If you ask,"What effect does combustion chamber shape (head and top of piston) have on engine performance with everything else the same?" I think that is what you mean.

Re: Piston perfromance
 

Chris, Chipper or anyone else: would a flat piston with notches be faster than a dish piston (everything else is equal)?

I thought the dish allows for a better burn rate but losing out on compression. Would you advise some one to build a dish if it was rated 20HP less than a flat with notches?

Would the combustion chamber in one be that much better than the other?

Re: Piston perfromance
 

Joe,
Assuming comparable compression ratio, there are instances in SBC Super Stock combinations where a properly shaped dish has a alight advantage over a similar combination with a flat top piston with valve reliefs. There are lots of other factors in that equation though, not just the dish vs. flat top comparison. That being said, the shape of the dish is critical for the advantage. For Stock combinations, the factory dish shape is a disadvantage in every situation I have seen.

Re: Piston perfromance
 

Same compression and reverse dome VS flat top the reverse dome whens every time.

Re: Piston perfromance
 

Dwight, thank you for the insights on the factory stock dish shape ... there are some 305 combo's that are identical except the piston. The flat top is rated 20 HP more, and killer fast. Was thinking why not run the dish piston -260lbs.

Re: Piston perfromance
 

Joe ,I believe there are other differences I think in cameros flat top engines are big cam dish are small cam.

Re: Piston perfromance
 

Lee, they are not both Camaro's, one is a Camaro and the other is a different body style.

Re: Piston perfromance
 

Joe -

Are you talking Stock or SS? In either case, the flat top engine and the later shallow dish piston engines are at least a point more compression than the early dished piston engines, so its not apples to apples.