Calculators - Wiseco Piston Inc.

We have consolidated some of our most helpful calculators into a single downloadable MS Excel Spreadsheet. This spreadsheet is temporary until we have online calculators built into the website, which will require no special software. Also listed below are a few commonly used formulas gathered by our engineers.

Helpful Automatic Calculators (Requires MS Excel)

Piston Speed (ft/min.)
a	= RPM
b	= Stroke of Engine (ft)
	Formula: 2 x a x b
	Example: 2 x 8000 x .333 = 5328 ft/min

Compression Ratio (Total Swept Volume)
a	= Combustion Chamber Volume at TDC
b	= Cylinder Displacement (cc)
	Formula: (a + b) / a
	Example: (100.00 + 823.70) / 100.00 = 9.237

Rod Ratio
a	= Rod Length
b	= Stroke of Engine
	Formula: a / b
	Example: 6.0 / 3.5 = 1.714

Rod Length
a	= Cylinder Block Length
b	= Deck Clearance
c	= Target Compression Height of Piston
d	= Stroke of Engine
	Formula: a - b - (c + (d / 2))
	Example: 9.025 - .025 - (1.0 + (3.5 / 2)) = 6.25

Piston Dome Volume
a	= Head Chamber Volume (cc)
b	= Gasket Volume (cc)
c	= Deck to Piston Volume (cc)
d	= Cylinder Displacement
e	= Target Compression Ratio
	Formula: (a + b + c - (d / (e - 1.00))) x -1
	Example: (60 + 10 + 10 - (823.7 / (9.237 - 1.00))) x -1 = 20cc

Piston Compression Height
a	= Block Length
b	= Stroke of Engine
c	= Rod Length
d	= Deck Clearance
	Formula: a - (b / 2 + c) - d
	Example: 9.025 - (3.50 / 2 + 6.00) - .025 = 1.250

Cylinder Displacement
a	= Bore (Inches)
b	= Stroke of Engine (Inches)
c	= Number of Cylinders
	cc Formula: a x a x .7854 x b x 16.387 x c
	cc Example: 4 x 4 x .7854 x 4.0 x 16.387 x 6 = 4942.2142
	CI Formula: a x a x .7854 x b x c
	CI Example: 4 x 4 x .7854 x 4.0 x 6 = 301.5936