Compression Ratio
#1
Compression Ratio
Hey guys, what size dished pistons will produce an 11.5 to 12:1 compression ratio.I'm thinking somewhere around 5cc but I'm not sure.Any help would be greatly appreciated. This is for a 99 GT 2v.
#3
RE: Compression Ratio
It depends on what brand piston you go with. For example: A 15cc Diamond piston produces the same compression ratio as about a 17cc Manley piston. Scott from VT engines told me this. Manley claims there flat top piston makes a 10.5 compression ratio, so you would have to go with a pop top piston from them to get that ratio.
#4
RE: Compression Ratio
There are some small variances in tolerances, and one company may be machining their pistons on the small side, and the other on the big side.While a 2cc variant would be alot, it is within the OEM spec'd tolerance. But, the only way to estimate the c/r is to use nominal numbers. If Manley advertises a 17 cc volume, then that's what you have to use in your calculations.
That being said, you'll want to go with something like a 1.8 cc to put you in the range you've defined. An aftermarket flat-top will net you a bit over 12:1.
Don't mess around with head gasket thicknesses. Leave them of stock thickness. I'd recommend you use an OEM gasket anyway. 4C2Z-'s are what you want.
That being said, you'll want to go with something like a 1.8 cc to put you in the range you've defined. An aftermarket flat-top will net you a bit over 12:1.
Don't mess around with head gasket thicknesses. Leave them of stock thickness. I'd recommend you use an OEM gasket anyway. 4C2Z-'s are what you want.
#7
RE: Compression Ratio
Well, you'd better make up your mind before you select a piston, 'cause you won't be able to run 11.5:1 to 12:1 c/r with a turbo.
David_K, why would he want a 'domed' piston? He can achieve 12:1 with a flat or near flat piston.
David_K, why would he want a 'domed' piston? He can achieve 12:1 with a flat or near flat piston.