Possible detonation, surging, down on power. Ignition timing seems to be one of the most confusing topics for too many people. I wrote the power timing thread years ago. I think it has helped a lot of guys, but the confusion continues. Most of it is not understanding the most basic distributor operation and not knowing how to use a timing light.
I have my initial timing at 12 degrees and total timing at 36. Is 36 total timing to much on a 430 with a bore of 30 over
It may be. Usually an all iron engine wants 30-34, but you’ll have to determine that. A race track or chassis Dyno helps. Highest trap speed or RWP coincides with best timing.
I just changed the bushing to a blue bushing and set my initial timing to 12 degrees and I got 32 total timing
Well I took the car on a test drive and it doesn’t have the get-up that it has with the green bushing
Why do you say that? I think its a great distributor. Been in my car for got to be well over 10 years. Hasn't missed a beat. Still have the original 6A box
Have we had this conversation before? Seems familiar. An engine run primarily at part-throttle will benefit from some amount of vacuum advance.
Did we? I don't remember MSD makes a good product. But its not for every application. I agree with you about vacuum advance. A little extra advance at highway speed does wonders for economy. But not everyone is concerned about fuel economy at highway speeds. You don't see many vacuum advances installed at the race track right? On my two other 455's, which are stock or mildly modified, I had to limit the amount of vacuum advance due to surging issues.
On the street and without race only rear gear ratios you need at least 8 degrees of vacuum advance ! You bought a race only Distributor . 8 degrees of vacuum advance at cruse rpms will pick up your fuel mileage and can cut your cruse water temps by 10 degrees, all while providing better throttle response and helping your oil to stay cleaner too Boot!
On my 455 in my 71 GS for example, Im running 12-1's, monster cam, 10" converter, 950 QF, etc. I have my timing set to 32 all in at 2500. That's all it needs. On a basically stock 455, you want 44-46 degress of total timing with the advance connected unless it starts to surge, then you'll need to cut it back
