RPM's - Crank or Rotors?
 

Probably a dumb question, but, are the RPM's registered on the tach the crankshaft or the rotors?

What is the ratio of rotor revolutions to crank revolutions?

Thanks.

crankshaft.

the rotors rotate at 1/3rd the speed of the eccentric shaft.

the rpm is the crank speed . The crank to rotor gear is three to one . That is controled by the stationary gear and the rotor gear

Eccentric, baby! The rotary has no crankshaft. ;) But the info is right -- tach reads main shaft speed, rotors turn at 1/3 the indicated speed.

-Max

what is the tech word for the shaft in the rotary??? So is it 3 shaft revolution is 1 rpm??? or is it 2 shaft revolutions per rpm??

1rpm is the e-shaft or the crank turning one complete revolution in one minute. 1000 rpm== the e-shaft turning 1000 revolutions in one minute . in one e shaft revolution the rotor has moved 1/3 of a revolution. Ok

Thanks, fellas.

djb

ok no I understand, thanks

At 6000 rpms, the rotors are moving at 200rpms

How do you get 200 rpm for the rotors at 6000 rpm shaft speed. now I am stupid

6000 RPM eccentric speed (as shown on the tach) = 2000 RPM rotor speed. The rotors turn at 1/3 the eccentric shaft RPM.

-Max

Yeah, 9k RPM eccentric shaft speed means the rotors are only moving at 3k RPM. Not bad!

typo-

do you guys know if the tach will still read the crank angle sensor with the egi fuse?

im doing a compression test and my readings are 7.5, 7.5, 0.0. the rpm on the gauge show 999. also it does the same thing on both rotors. when i crank the car, the tach dosnt bounce. it acts like its not counting the revolutions. do you know how to check for bad sensors or what the problem might be.