Saturday, May 31, 2008

Cylinder Volume

On several engine, cylinder diameter wider than the cycles itself, that give short piston cycle and lessen of power caused by friction of piston ring with cylinder wall. Other benefit is the possibility to install valve so that give more volumetric efficient and engine performance.

Cycle Volume and Cylinder Volume
Cylinder volume is volume that shifts by shaft if the shaft moves from the top position to the bottom position. For giving illustration the parameter will represent as bellow:

Diameter : d
Cycle height : S

Cycle Volume in unit cm3 and dm3 and represented as Vs;

Vs = ¼ π d2 x S or 0.785 d2 x S

Engine with cycle height 80 mm and cylinder diameter 80 mm have cycle volume 402 cm3, the calculation is as follows:

Vs = 0.785 x 82 x 8 = 402 cm3 (rounded up)

The cycle volume calculation above represents in cm3 unit or commonly called as cc, cylinder diameter and cycle height represent in cm unit.

To calculate cylinder volume for engine with four cycles is four times of cycle volume, so the formula to calculate cylinder volume becomes:

V = 4 x Vs , where Vs are each cylinder volume.

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