I have just bought a 2.0mm HKS gasket too. I'll be using the 8.0 GZE pistons. Max 11.7psi boost.
As far as I can tell, the HKS figures are based upon the Bigport 4AGE pistons (8.5:1).
From my calculations, my setup gives the following compression:
COMPRESSION RATIO CALCULATOR
Fill in Numbers 1 to 8 to give an answer
1 . Piston Diameter 81.50 mm
2 . Piston Stroke 77.00 mm
3 . Piston Dish/Crown 12.00 cc
4 . Number of Cylinders for a crowned piston
5 . Head Gasket Cylinder Diameter 82.00 mm
6 . Head Gasket Thickness 2.00 mm
7 . Percentage of Compression 0 %
8 . Volume of 1 Combustion Chamber 37.00 cc
1 Cylinder Capacity 401.69 cc
Engine Total Capacity 1606.78 cc
Volume of Compressed Head Gasket 10.56 cc
Volume of Combustion Chamber 37.00 cc
Compression Ratio 7.74 : 1
I'm sure I'll be corrected if I'm wrong, but I've gone for a lower compression ratio as there's to be no intercooling. Whether or not you use intercooling, a lower compression ratio will allow you to use higher boost (without detonation).
For 13psi, I'd be going for the 2.0mm gasket.
I can send you the calculator spreadsheet for the above if you like.
Sat, 05 February 2005 02:57
