Locked out distributor advance question
 

I recently locked out the advance in my distributor. I took the car out for testing with my backup engine last night and while the engine has some issues, the distributor worked out fine, and I had no trouble cranking when hot. But the timing did wander back and forth a couple of degrees, and when I put it in I could feel the rotor moving back and forth just a little.

I'm pulling the distributor out anyway to swap back to my good engine now and I'm thinking of putting a little tack weld between the plates to prevent any movement at all. There's no electronics in this, just the magnetic pickup. I don't think that would be bothered by one second of arc.

What do you guys think, good idea, bad idea? Any drawbacks other than the obvious increased difficulty in restoring centrifugal advance later on?

Re: Locked out distributor advance question
 

Dave,

another option is to drill through both the fixed and movable plate and install a roll pin. Doing so gives the option to go both ways.

Re: Locked out distributor advance question
 

That's a good suggestion by Larry. If you decide to put a small shot of weld on instead, take out the pick up and cover the sensitive areas with tin shield or pull out the shaft. Always place your ground cable as close to the weld area as possible and put the weld where it could easily be removed with a thin grinder wheel.

Re: Locked out distributor advance question
 

the timing wander could also be caused by the timing chain and or the gear lash on the cam/distributor

Re: Locked out distributor advance question
 

Before I installed it I held the gear in one hand and the rotor in the other. I could feel a little back and forth movement in it.

Re: Locked out distributor advance question
 

Two things come to mind . First , if you tack weld the plates ,t will be very hard to index the distributor cap . It would be better to drill a hole through both plates then file a slot in one , so you can move the reluctor around to get the timing and the cap index correct . Second is to shim the shaft to get minimum endplay on the gear .

Re: Locked out distributor advance question
 

MSD distributor?

Re: Locked out distributor advance question
 

No, It's a Summit brand, whoever they got it from.

Re: Locked out distributor advance question
 

I'll know more tomorrow morning when the distributor comes out, but my plan at the moment is to remove the gear, pull up enough to be able to slip in one or more flat washers as needed to take up the gap, then reassemble. With the right thickness of washers it should hold the plates together firmly when I tighten down on the nut.

Totally reversible too.

Re: Locked out distributor advance question
 

The MSD units are known for not having enough threaded section on the little pin that locks the plates together. A flat or locking washer behind the nut takes care of it.

Something to check, anyway. -Al