blackangel327

iTrader: (3)

I did a search, but couldn't come up with anything. I got to wondering what would be more efficient, if you use a High CC head with a flat top or Dome piston to achieve your desired Compression Ratio or Low CC head with a flat top or Dished piston to achieve your target Compression ratio?

BigJls1

no one has enough money or time here to answer that, there is so many variables. I am not very helpful in you question but I'll get u a bump.

veee8

iTrader: (40)

I went with large cc chambers on my heads, so I could run a flat top piston. So I could have a little bit more meat on the crown, being FI.

blackangel327

iTrader: (3)

thats kind of what i was thinking as well, i mean if you dish your piston it seams to me that its not going to atomize as well but thats why i asked because I would like to know before making an assumption and making a wrong desision

MY99TAWS6

iTrader: (3)

Don't think it matters much at all. More important is what compression you wind up with and there is big debate on that as well. I have seen guys with low compression 8 or 8.5 to 1 say they didn't notice any doggyness off boost and guys say that you should go with 9.0 or 9.5 for off boost. I do see factory using low compression in lots of their turbo cars. And we even saw low compression in 70s down to like 7.6 in my 400 trans am. Yet the car still seemed to do not too bad with that low compression.

Lower compression is useful as you can run more boost and boost makes more power than compression. I went with 9.5 to 1 on my build. With 72cc afr heads and custom wisecos. It seemed fairly reasonable compression ratio and I have no desire to run boost likley much past 12 or maybe 15 tops on my setup. I do plan on running alc/meth injection full time.

blackangel327

iTrader: (3)

this isn't about power though its about atomization of the fuel to prevent detonation. I know what compression ratio I'm going with with what amount of boost, I just would like to know which is more efficient.

ls1290

iTrader: (20)

If at all possible you want to avoid using dome pistons as they affect the burn and travel characterists of the flame as it comsumes the air/fuel charge. The best solution is the choose the heads you want for your application and then size the pistons to reach your desired compression level. If the heads you want to use will result in a lower compression level that what you want with flat top pistons, then mill the heads to create your target compression level.

Keith

Websy21

iTrader: (34)

I wouldn't mill heads in a boosted application, that means less deck which means less clamping strength.

blackangel327

iTrader: (3)

well they are 70cc heads, and I'm looking at right around 9.5 Compression. just wondering what would be more effiecient, just wanted to see what everyone else thought