
1. Measure gear width, (W)
2. Measure bore chamber of one of the gear chambers, (D)
3. Measure distance across both gear chambers, (L)


1. Find piston area from piston diameter, (A)
2. Measure length of stroke, (L)
3. Count number of pistons, (N)


1. Measure width of rotor, (W)
2. Measure shortest distance across bore, (D)
3. Measure longest distance across this bore, (L)



47 x W x (2D  L) x 
(L  D) 
2 


A x L x N x 1800 ÷ 231 

94 x W x 
(L + D) 

x 
(L  D) 
4 
2 



A speed of 1800 RPM is used in the formula.
At other speeds, GPM is proportional to RPM. 

A speed of 1800 RPM is used in the formula.
At other speeds, GPM is proportional to RPM. 

A speed of 1800 RPM is used in the formula.
At other speeds, GPM is proportional to RPM. 


6 x W x (2D  L) x 
(L  D) 
2 


A x L x N 

12 x W x 
(L + D) 

x 
(L  D) 
4 
2 

