Advance adjustment(s)

73SwingerBuild said

I had/have the same problem with the mystery 340 I bought and put in my swinger (I call it a mystery because I do not know what cam/compression it has and it basically came to me as a 2,000 mile crate motor.

I believe the distributor is a stock Mopar part (based on the part number), but I have no idea what the springs are. I found that the issue goes away if I run the motor hard for a few minutes and then park it, as it idles fine right around 700-800. However, if I rev the motor in neutral it will let the idle creep up to 1,000-1,200.

I wonder if I'm having the same issue with the springs that you have. Waiting for somebody more experienced to chime in here.

Thanks for posting.

-Mike

Click to expand...

My distributor isn't new..but the car has been sitting in the garage doing nothing for a l-o-n-g time since it WAS new. I may find out differently when I get around to taking the distributor apart, but I am assuming the mechanism in mine to be in good shape.

I can think of several things that might cause what you describe in your rig...a sticking spark advance mechanism being one of 'em.

I see the YH (Mallory) 'kit' at Summit for a lot less than I had been seeing it. With a bit stiffer spring set and changing the stops, I think what I'm looking to fix will be fixed.

I'm not looking to get into a 'It doesn't matter!' session, but my initial is 2º, and I want to change that, too.

...by doing the same thing: Tightening the springs and changing the stops.

It'll all get sorted eventually!