SLANTY BLUES
here is a link to a static compression calculator
RSR Static Compression Ratio Calculator
the BR site also has a dynamic compression calculator and other useful info.
This is what I came up with on SCR. Looks low enough to not be a problem. The dymanic C R ( not sure if I calculated correct) came in at 7.57 .
Bore
3.43
inches Diameter of cylinder
Stroke
4.125
inches Distance piston moves
Head Gasket
thickness
.040
inches Measure your head gasket tthickness. It's usually 0.040", but not always...for example, on K1200 BMWs it is 0.070". On 113/135" ORCA motors it is 0.00 because they use metal seals and no head gaskets.
Deck Height
.17
inches Move piston to TDC, and measure the distance between the flat top surface of the piston (not the top of a dome or the bottom of a valve relief) and the top of the cylinder. Enter a negative number if the piston's flat surface sticks up past the top of the cylinder. At TDC the piston will "rock" so be careful in your measurements. ORCAs are .035".
Piston top
volume
0.00
cc's You'll have to calculate this value the hard way i.e. do it yourself or call the piston manufacturer. Enter a negative number for a domed piston. Enter a positive number for a dished or dimpled piston. If you have a flat piston with no valve reliefs enter 0.00.
Combustion
Chamber
63
cc's Get out your 100ml burette, your light, non-nasty grease, your handy dandy plexiglass or lexan sheet, your Marvel Mystery Oil and a six pack and get ready to party. Don't forget to cc the combustion chamber.
Static Compression Ratio:
7.58
