Rotor Question

B

barnstuf

Well-known member
I recently ordered a quantity of new rotors from a well known supplier to the hobby. A few have a bit of looseness where the metal contact is riveted to the basic rotor. This play is very little as there is a shoulder on the rotor that limits side to side play to a thousandth or two, but there is also the same looseness up and down, but again only one or two thousandth. I feel a new product should not have any looseness at all, and before I return them I would like to know if this looseness would affect performance, or if it would make setting the timing difficult. In other words I want to present a solid case for making a return of the rotors. I have spoken with the supplier and was told to return them for inspection, no promise to replace was made.
 
Rich,

I know what your saying. Thoughts for the parts house.

1. It's only going to get looser..
2. It could in time hit it's counter part on the distributor body..if it gets loose enough..
 
I found a sililar problem on a rotor a couple weeks ago. With a ball peen hammer I gave the rivet a couple of "peens" and it tightened right up.

Can't hurt to try.
 
I've found that occasional mis-fires can be caused by spark arcing through rotor & grounding out to dist shaft. Looking up inside hole in the bottom of rotor, I've found a rainbow type discoloration as a possible indicator of shorting out?? Bill W.
 
Phred said:
I found a sililar problem on a rotor a couple weeks ago. With a ball peen hammer I gave the rivet a couple of "peens" and it tightened right up.

Can't hurt to try.
Click to expand...

That's what I would do. It's an easy fix and not worth the time and expense to mail them back.
 
I've also gotten brand new rotors that fit so tight on the shaft they crack when pressed on.
I use the Standard Motor Products rotors now. I get them from my local auto parts distributor.
 
Most of the rotors I've seen leave a lot to be desired. Most either fit loosely to the cam or the tip is loose or both. A number of years ago I ordered a bunch of model A electrical parts from a local parts store across the street from my body shop. The parts cost several times more than they would have if I had ordered them from a model A parts vender. One of the rotors wouldn't even run when installed. There was a sign posted on the counter, NO RETURNS ON ELECTRICAL PARTS!!! I didn't even try. No big loss but a lesson learned.
 
Several years ago I bought some caps and rotors from Little Dearborn in MPLS. and from Bratton's, and all of them fit perfectly to the cam and the distributor cast body.

BTW, I have seen some repro caps and rotors that fit very loose on the shaft and body. I'm not sure where they came from.
 
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Thanks for the input. I was able to tighten the rivet on each one with a well placed blow of a peen hammer after finding a piece of wood of the correct thickness to keep the rotor stable during the process. All 22 were fixed with no breakage.
 
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