My engine builder is the guy that was in GM high techs Feb 06 issue Mr Rob Barth and he is building me a forged 347 with flat tops and just a thicker head gasket. He had nothing good to say about dished pistons and did not want to use them. His car has flat tops and has 10.2:1 compression and he got 840 rwhp out of it and was able to push lots of boost with C16. He even made great power with 91 oct pump?

I just was lookin for opinions on benefits of flat tops and dished pistons? Anyone else runnin boost with flat tops forged bottom end?

 

I ran flat topn in my old motor (-2cc reliefs) at 10:1 compression and it did OK, 9.70s or so. But thats because thats what was there when I bought the car, if I was building a new engine I would rather use normal off the shelf gaskets and dished (or reverse dome) pistons. It really depends on what your goals are, I would guess just about everyone here with a high horsepower car is running a dished piston of some sort - especially with a 4" stroke

 

What would better dished or dome? Why or is there a better one?

 

Thas kind of a loaded question, lot of people swear by the reverse dome over a full dish but really on a forced induction car quench isnt that critical.

Different theories abound, if you are having someone build the engine and they want to use flat tops I wouldnt argue. Lot of different combos out there that work well and if thats what he wants to use and he has had good results just roll with it.

 

Thanks KP

 

dish piston isn't good because they actually create detonation reason is that quench see this an opportunity to just escape there and creating a lean side and when the spark ignites the lean side already been spark faster than the rich side and create 2 flame fronts which when they hit each other they create a sonic boom and yatata there also a lot of factor that play and additional reason why cylinder 1 or 3 has either has holes or flown to mars. make sure you want a nice quench area and don't' increase the cc in the piston do it in the cylinder heads so the only thing to you can do is control how much quench you need by a head gasket. but the deck and the piston should be flushed aim a .032-.042 quench thickness or in that ballpark..

 

You're replying to a post that's 17 years old bud......