Re: Rotor Arm Gap

Posted by Bob Bidonde on April 16, 1998 at 07:05:22

In Reply to: rotor arm gap
posted by John Winchester on April 16, 1998 at 00:13:01

: The gap between the rotor & distributor body electrodes affects ignition timing (idle smoothness; gas mileage; top speed; etc.) and should be kept small. This gap is just as important as the spark plug gaps! There are five significant considerations: (1) the roundness of the distributor body. Some are considerably out of round which can be detected by measuring the gap at all four electrodes; (2) the fit of the rotor to distributor shaft, it should be snug, but not a press fit. Many rotors fit very loosely; (3) vertical alignment of the rotor electrode to the body electrodes. Bend the rotor electrode to center its travel across the body electrodes; (4) thermal expansion as all of the parts get hot, especially from exhaust manifold radiation; (5) distributor shaft to bushing fit should be 0.0005" - 0.0030". With good round parts and proper fits, I have successfully run the gap at 0.010" -0.015" for thousands of miles. Larger gaps retard ignition performance. I flaten (bend in a vise) & filethe rotor electrode to set the gap. Rotors with a brass electrode are the easiest to work with. Sometimes it is necessary to file the distributor electrodes as well. If the body is out-of-round enough to prevent getting all for electrodes @ 0.010" - 0.015", then reject the plastic disrtibutor body.

Follow Ups:
Re: Rotor Arm Gap DJ.Voyce April 17, 1998 at 01:19:09(0)
Distributor body gap Rick Black April 16, 1998 at 09:31:01(0)

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