I think my distributor is A OK...but I have a timing question. I HAVE read Larry's timing thread...many times just to clarify. I have a stock 71 Skylark with a TA manifold and TA 212 cam. Nice Quadrajet and Pertonix unit in dist. A couple of years ago my original balancer fell apart and we replaced with a used stock Buick unit. The timing notch was off soI found TDC(it's dead on now) and went from there. Since then my timing changed from 14 initial and 38 total to19 initial and 48 total. Idid not install the cam but the guy who did said he did not degree it.So...here is my question. The car runs OK for an engine with 100K+ miles on it. It doesn't over heat, pulls enough vacuum to run A/C at idle. All is good. Is it a big deal that my initial is set so high and total is 48...not 36+-?? Enjoying it as a daily driver (crappy Atlanta GA traffic 20 miles each way and it runs great plus is more fun to drive than the truck) since the MPG is about the same as my truck! Thanks!-CB<o></o>
When you say total timing are you counting the vacuum advance as well? If so then you may still have around 30-34 degrees of timing depending.... So let us know if you have the vacuum advance hooked up when you checked your total timing... These engines will run best with 32-36 degrees of total timing plus 10-12 degrees of vacuum advance at part throttle and light load. I use the crane adjustable vacuum advance, I limit it to 10 degrees and use a ported vacuum source so it does not add timing at idle, only at part throttle light load. Use a vacuum gauge to let us know how much vacuum you have. The only real way to ensure that your TDC mark is accurate is to use a piston stop. We can get close by putting a wine cork in the plug hole and then turning the engine over till the cork pops out but you want to get to that exact point where the piston is at it's highest in the number 1 hole.
Ok...that makes sense. I took off the adjustable can I had on my dist and replaced it with one that has 10 deg of vacuum adv. When I tuned it I disconnected the ported vacuum and got idle etc just right. When I checked total timing I had the ported vacuum hooked up...that's the extra 10 deg(around 2800+ rpm)? I did find TDC using a piston stop. I am getting 11hg of vacuum at idle..didn't check to see where it went as the rpms increased. Thanks for the help. Chris
Then I would back off your initial timing 2 degrees and that should put you at 36... Good work getting the timing mark relocated properly!!! Now if you hook the vacuum advance to a manifold source which gets vacuum at idle you will likely raise the vacuum reading of the engine to about 17 which would be a good idea as long as the engine does not idle too high with all the timing. I would also play with the idle mixture screws to get the most vacuum when in gear at idle with wheels blocked or someone holding the brake.
