BlackEclipse
10-09-2005, 11:29 PM
I was counting teeth on the various sprockets that are all somewhat linked to the timing belt. With these teeth counts, you can figure out the rotational speeds of various engine components in relation to the crankshaft.
Sprocket # teeth
------------ -------
outer crank 24
inner crank 38
upper balance shaft 19
cam 48
oil pump outer 18
oil pump inner 21 (also known as the oil pump drive gear)
lower balance shaft 14 (also known as the oil pump driven gear)
So....
The camshafts spin at 1/2 the rpm of the motor.
The oil pump spins at 4/3 the rpm of the motor.
The upper balance shaft spins at 2X the rpm of the motor.
The lower balance shaft also spins at 2X the rpm of the motor.
Calculation for the lower balance shaft:
24 21 4 3 4
-- * -- = - * - = - = 2
18 14 3 2 2
(If your motor is spinning at 7,000 rpms then your lower balance shaft is spinning at 14,000 rpms)
Sprocket # teeth
------------ -------
outer crank 24
inner crank 38
upper balance shaft 19
cam 48
oil pump outer 18
oil pump inner 21 (also known as the oil pump drive gear)
lower balance shaft 14 (also known as the oil pump driven gear)
So....
The camshafts spin at 1/2 the rpm of the motor.
The oil pump spins at 4/3 the rpm of the motor.
The upper balance shaft spins at 2X the rpm of the motor.
The lower balance shaft also spins at 2X the rpm of the motor.
Calculation for the lower balance shaft:
24 21 4 3 4
-- * -- = - * - = - = 2
18 14 3 2 2
(If your motor is spinning at 7,000 rpms then your lower balance shaft is spinning at 14,000 rpms)