BobG

As a prelude to my starter replacement, I was adjusting the dwell on my Goat. Twice in 3 weeks, it had drifted from 30 degrees to 20 degrees ... first was after the 400 + mile trip to PA for the fourth, and the second was after returning. Both times, it didn't seem to have the power it should have had, so I checked the timing and found the dwell had drifted. This has raised a couple of questions...

1. When I get a dwell angle I'm happy with, and the goat is happy with, should I put some loctite on the screw threads?

2. I currently have the dwell set to 31.5 degrees, and have a marked improvement in performance (I can light up the back end on a 1-2 shift every time now, not just on certain types of pavement) but the tradeoff is that it's a bit harder starting now, and I can't seem to get a good idle speed (cold or hot). Is this a carburetor issue or a ignition timing issue?

possibly pertinent info: 1970 400, Holley 650, initial timing at 12 deg BTDC @800 RPM. current best idle: 650 RPM

 

lars

If the dwell keeps changing, install a new set of good quality points. Use NAPA part number CS786 with condenser part number RR175. Set the dwell to 30 to 31 degrees.

Keep in mind that every one degree change in dwell changes timing 1 degree, so be sure to check your total timing after each dwell adjustment. Total timing should be 36.

More dwell (more coil saturation) should actualyl make the car start easier since you're getting a better spark. However, when you crank the dwell from 20 to 30 degrees, you are retarding the timing 10 degrees.... it may be that the car wants more timing, and that's what you're seeing.

BobG

Thanks Lars, I'll check out my timing again and see where I am.

BobG

Thanks Lars .... I checked the timing, and found it at 6 degrees. I set it back to 12, and the ol goat runs sweet now ...

lars

Keep in mind that intial timing is irrelevant - the engine sees total timing. Be sure to check and set total timing to 36 degrees.

BobG

Thanks, Lars, That's already been done. I printed out your "tuning for beer" post and inserted it in the tune up section of the service manual.