timing problem figured out (swervin ervin)

[bigd65]

well it seems that i found the problem. the springs (after market) were all to light and letting the advance plate open all the way up at WOT. i barrowed a dial back light and set it to TDC. when i would raise the rpm's it would go to 25* and if i would gas real hard, i could 30* to come around. that is with no vacuum advance, only mechanical. well i also barrowed a distributor from same guy and is springs were heavier and wouldnt let the whole advance plate go around. i put on the heaviest stock springs i had and set the timng to 12* and went down the road (back road ) very little sparknock. so i came home and checked it again and i could get 25* to come around but had to gas it hard. so i set it to 8* and hooked everything up and that was that. now i know i need a new DIZZY. one with the adjustable advance limiter bushings built in

[swervin ervin]

Jeff,

you have aftermarket weights too, right? With stock weights, you should have around 20 degrees advance. Swap in some stock weights with the springs. Then you can probably raise the initial back up to 12-14.

[bigd65]

no that is with the stock weights (60) and a (468) center plate . i had the timing at 12* , i looked again but changed it to 8* to rid all the sparknock.

[swervin ervin]

I'm not up on the numbers of weights and plates, but I do know stock HEI's have 20 degrees of advance built in. There can be minor differences of 1 or 2 degrees, through wear and such. If you have more than 21 or so, something isn't right. If you can make it go to 25 or more, you have a mixed up mess of weights and plate. It shouldn't matter how many rpm you turn it, 20 or 21 degrees is all you should have.

Remember, with a dialback light, zero it out when at idle and vacuum disconnected. Then slowly raise it to 4500 rpm and check the advance. With a good HEI, you should have 20, or a max of 21 degrees. No more, not any. It should move up the scale smoothly with no jerks or sudden movements.

Do yourself a big favor and get rid of that distributor and get a good one.

[bigd65]

I KNOW I NEED A NEW DISTRIBUTOR.

this is what i did

i set the timing at TDC, because at this point i just wanted to see how much mech. adv i was getting( no vac adv). i set the dial to 20* to see if i could get it to come back to TDC and it did and then some. so i set the dial to 25* to see if it would come back around and it did, i figured, let me see if more would come in, so ran it back up again to get it to come back to TDC (this is 25*at this point) then i gassed it harder to see if more would come in. well it did, approx 5* more so now this is equalling approx 30* and from TDC. this explains why i couldnt get a higher timing than the TDC i was always complaining about. now when i get another EGR valve, maybe i can set it even higher. where does the egr hook-ported or manifold

as i was compairing to another dizzy the guy loaned me, i noticed his was the same plate and everything but his was a ESC, but that part wasnt the deal. anyway, his seemed alot tighter than mine, even though i was using the 2 heavy springs from the crane set, it still was to loose. so with all the springs i had, i found the 2 stock springs i had and there it was, just as tight as the other. i was comparing the springs and found that the after market springs would stretch farther than the stock springs. its not that they were really tighter, they didnt stretch as far. so here i am.

[swervin ervin]

It's like you are fighting a loosing battle. I would start from scratch with another distributor. As cheap as you can get another one from the junkyard, it's not worth it. Don't get one for the ESC though. You don't need it, or want it.

[bigd65]

i am going to get an after market one. i am thinking there is a machine shop in houston that sells recurved dizzy's. i may look at those