[icingdeath88]

First we have to calculate the cylinder volume at TDC.

The CR is 10:1, the stroke is 75mm, the bore is 96.9. (If any of these values are wrong, please let us all know.)

If the CR is 10:1, then that means that the volume at BDC (bottom dead center) is 10 times the volume at TDC (top dead center).

The difference between the volumes (BDC - TDC), is given by the volume of a cylinder of height = stroke, and diameter = bore: V=pi r^2 h = pi x 48.45^2 x 75 =

10 x TDC = TDC + 553093.68 mm^3
...algebra...
TDC vol = 61454.853 mm^3
...more algebra...
and BDC vol = 6145485.33 mm^3

Any thickness added or subracted to the headgasket corresponds to volume added or subtracted to the TDC and BDC volumes. Lets say that we're considering a .140" headgasket and the stock is .066". (remember, when talking headgasket thickness, we are always talking about "compressed height", the height when it's all assembled and torqued to factory spec). The difference is .074", which is 1.8796 in mm.

This volume comes out to 13861.26 mm^3.

Add that to TDC and BDC, and we have 628409.80 mm^3 and 6159346.60 mm^3, respectively.

The compression ratio comes out to: BDC/TDC = 9.801:1.

Still pretty high, but you might be able to get away with 87 octane. Not exactly turbo friendly though.

There ya go. God, I'm such a nerd.