May some1 plz explain to me the difference between Flat top pistons & reverse pistons? Which one is better?

 

When we built blocks back in the 70's,a flat top was almost a stock piston. It had more compresion than the standard one. A high dome would crush your mix allot harder. The motor had to be built for it. A reverse was used for turbo mods. I may be wrong, I hope the boys and girls chime in on this to set this right.
HOLLYWOOD

 

flat tops are just that, flat on the top. Reverse dome(dished)pistons you arent going to use. Best to either use flat tome pistons or domed for your build.

 

basicly, in a nut shell flat tops are best, but if you need to change compresion with a certian combustion chamber size AND keep your quench correct you may need a dished piston, nothing wrong here as long as the quench is still around .030. and the cylinder presure is what your cams require.

a pop up is used to raise comprsion, but the heads will require some CCing to make the compresion right for your cams, and equal between the cylinders.

a builder will use any combonation to get the desired quench and compresion for the desired results.

 

Technically I think domes are best for combustion turbulence/af mixture etc, but flat tops keep things simple and are very easy to work with.

 

deffinantly a highly debatable topic, lots of builders belive that the domes obstruct the flame travel and interfere with combustion.

to me, the combution chamber should be the only factor in controling flame travel and use a flat top piston, but I currently run a pop up, and it has had no ill effects on my bike.

Phil M runs an 11.0 to 1 120 with a reverse dome or dish piston and has incredible results.

the quench I feel is the most important issue above all.

 

I will agree its very debatable with great arguments on either side of this coin, kind of why I said what I did.

 

The "dome" on a T/C, or Evo engine, is basically a flat-top type piston, by design, as opposed to large, raised dome pistons of yesteryear, that inhibit flame travel, and block air flow characteristics as well.
You need to use what is needed, for the intended build.
Scott

 

I agree with Scott, you should run what you need for the build to get your desired results. I too am running slightly dished pistons in my 120" at 10.5:1.