Big Boyz Head Porting - EVO Compression and Displacement Calculator



EVO Compression and Engine Displacement Calculator
EVO Compression and Engine Displacement Calculator

Bore�	�inches	Stock 80=3.498, 96=3.625

Stroke�	�inches	Stock 80=4.250, 96=4.625

Rod Length�	�inches	Stock=7.440

Head Gasket Thickness�	�inches	Stock=.045, Cometic MLS� .030� or� .040

Head Gasket Bore�	�inches	Stock 80=3.600, 96=3.750

Cylinder Head Volume�	�CC's	Your measured volume should be entered here

Deck Height Front Cyl	�inches	Negative number if piston�
Rear Cyl	�inches	is ABOVE cylinder

Optional Piston Diameter�	�inches	Measure above top ring**
		** Leave Both at Zero OR enter BOTH values
Optional Top Ring Land�	�inches	Distance from piston crown to top ring**

Cylinder Expansion�	�inches	.020 to .040 �is generally accepted for a Harley�

Piston Dome Volume�	�CC's	Stock 80= -1.500 enter only 1 piston, not both

COLD Compression (Static)
HOT Compression (Static)

CI Engine Displacement
CC Engine Displacement


Corrected Compression�			Convenience Calculator
		From�
OR
** Enter Intake Close ABDC�		To�
** (Set to ZERO if using a Selected Cam)

Cold Corrected Compression
Hot Corrected Compression
Cold Cranking Compression


Altitude Correction�
Feet above Sea Level�

�Cold Cranking Compression

Values in RED are approximate.� Use actual measured values only.� This calculator is supplied as a convenience and intended to be used for estimates only.� We make no warranties, implied or expressed, to the accuracy of any data or calculations presented here.