anyone tell me what the maximum advance on a distributor is? Mine is showing over thirty degrees mechanical without vaccum. In other words, I set the distributor initially on 15 degrees at idle without vaccum. Speed the engine up to 2500 RRM and the timing shoots to at least 45. I adjusted it back to center or "0" the timing light out, let the engine run back to idle. Turn off the engine and you can't get the engine to start unless turning the distributor back to the initial 15 degrees again. bad distributor?

Is it pinging? How are you telling it's at 45 total?

I have a timing light that has an adjustable dial on the back. I start at idle with the dial showing approx 15 degrees. I heat the throttle up to approx 2500 degrees and adjust the dial to whatever it takes to make the timing mark on the balancer go back to "0". Then I look at the dial and see 45.

yup a stock distributor can have that much advance or more. ive seen 34 mechanical advance before

Distributors are Universal fit, which simply means they are set up for nothing in the Universe.

That's why we curve a thousand distributors a year

Now if you have a 360 motor in a tree chipper then that distrbutor might work.

Okay, this is for a big block. Does this mean that the advance on a big block once set isn't at 35 but something higher? I guess that is what it means to curve a distributor. If the maximun timing is suppose to be at 35 with a big block too, then I am going to have to add material to the slots to reduce the maximum advance, right? And, oh yeah, this reading is with the vaccum disconnected. With it connected, the maximum timing is out of sight. Maybe this is why my engine has never really been a super great perfomer.

I'd still like to know if it's pinging. If it's not then no way does it have that much advance i'd look into another timing light.

Pinging? When does the pinging matter. Inititally under load, or at speed with new pressure on the pedal. Reason I ask is that there is pinging anytime I apply new pressure on the pedal.
I replaced my timing light last night. The one I have been using for years has been dropped off the car. This created a small problem in that it would not light up under 21 degrees. It was very accurate above 21. The new light? Is very accurate and showing the exact same thing as the old light. 15 initially, 52 at maximum @ 3000 RPM and above. I am confused too. I replaced the newest distributor with the one that has been on the engine for eight years. The same thing is showing with it 15 degrees at idle, 52 at maximum. Help!

You have a few options...

I assume it is a stock distributor, you can dial it down so at 3k rpm you get 36 or so (and let the initial be what it is), get the distributor recurved by welding up the slots and grinding them down, or the best option is to get a mopar performance distributor which has an adjustable mechanical advance, and set your initial where you want, and set the total mechanical back to what the motor wants at WOT.

I mention pinging because if there was no pinging when driving then there is no way you could have that much advance. If driving the car you had no pinging then your timing light is wrong or dial is wrong or something. There isn't any pump fuel avail that would allow 50 Degree's advance with out it pinging. It was only meant as a quick check to see if timing light was working right. I'd recurve the dist. I did mine. Car wants 22 degrees initial. Curved mine for 38 total in by 2800 rpm. I have the MP dist with adjustable advance.

Dougsmopars, thanks for the response. I don't have a clue about recurving a distributor. Rapid Robert is sending me a curve chart that he has.
I haven't even heard of recurving the distributor.
I don't understand why I have been able to drive the car as long as I have without problems, but I have always had the pinging under pressure from aceleration UNLESS I full throttle it in a lower gear. The older distributor is one I purchased with the chrysler ecu when I started driving the car eight or so years ago. The latest distributor was purchased based upon recommendation by Rick Erhenburg. Its a 71 big block reman. He was very specific in the one to get. Would the lack of power, based upon what feels like missing be likely because of the timing too far advanced.

Last question, how do you fix this? Recurve by adding metal to the slots? I belive that is what Rapid Robert is talking about.

One other thing, I have spent some time discussing the timing with my machine shop. They are assuring my that my compression is not high enough to cause this pinging. I use 93 octane all the time. Once, I added race gas to the tank and it seemed to eliminate the knocking. I need to get some more gas now, so I will add race gas in it now to see if it helps.

Thanks again.

I have tried to set the curve at 3K at 35 degrees. I turn the engine off and the engine will not start until I back it off again to the 15 degrees. I can't do that everytime I jump in the car to go somewhere. Plus it really doesn't seem to want to run well at that setting. Any ther ideas. I am game for all the help I can get.

sorry I missed this advice. That is what I think I am going to have to do. Now how do you take the distributor apart to get to the slot plate. Thank you

We know nothing about this BB,yet we are quick to give timing advice! ALL engine combos want something a little different. Iron head? Alum? Stroker? Cam selection? Comp. ratio? Remember....it's the "pinging" we DON'T hear that causes big trouble! Need more info..but max timing(w/o vac) will probably end up @ 38 or less!

Iron head 452's from a 77. Standard stroke for big block. Hughes 2832 cam, standard rockers. Should be 10:1 base upon piston specifications. Now the pistons where suppose to be at "0" deck when purchased but machinist had to trim deck .020 so they stick up above the deck .020. Once again 52 degrees max. Now one other thing, the MP distributor has a vaccum advance in its pod. I tried to back it off ccw as Prof. Erhenburg says to do. It didn't change a thing. I backed it off three full turns without a change. Not sure that is normal.

Wow! Great! That is great information. I now know what I have to do. Thanks.

If you have one of the MP electronic dist it maybe one with adjustable advance. You know once you have the reluctor off.

If you have 35 total at 3000 rpm at what rpm are you finding 45? With a total of 35 at 3000 you should not be to advanced to restart the motor? Now i'm getting confused??????