I had my carb rebuilt on my 70 supreme 350 -4 brl, several years ago, then the car went into several body shops, But was still being started. The guy told me he scoped the engine and the slight miss was due to a worn gear on the distributor. The car usually does this when warm but otherwise runs good. I’m still running points. Do this sound correct that the gear is worn?

 

If he picked this up on a scope either the distributor bushings and or the cam lobe that opens the points are worn. This is detected by a "bent/bowed" dwell line picture on the scope as the dwell varies between each cylinder.

Forum members know of a couple of old school distributor shops. Pull it out and send to someone with a SUN brand distributor machine that can repair it and put the curve to factory spec.

Good luck!!!

 

Thanks, I did just pick a rebuilt delco off a guy cleaning out his garage, I’m gonna have it changed and rebuild the original

 

Great, is the motor and drivetrain stock? If not forum members can suggest specs for recurving based on what drivetrain/mods have been done.

Forgot to mention that varying dwell also means varying ignition timing. If the ignition timing varies when the distributor is good that can be a worn timing chain set. If the timing chain set is worn then that also means valve timing is off/late costing performance. Lots of performance can be "left on the table" or gained through tuning.

Good luck!!!

 

Thanks, the motor is stock, I bought it off the original owner back in 2007. It has 54800 miles, I was thinking of adding a small cam, still has the stock Rochester on it. Motor is super quiet. Finally got painted in April, and added duals and h pipe last week. I would a little more power out of it.

Here’s a pic