timing advance (to much)

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o1heavy

o1heavy

1974 dart sport
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got a stock 440 in a 78 dodge d300
trying to milk all the performance i can out of it
having trouble with the mechanical it just has to much
and causes it to ping it goes as high as 50 with high rpm prolly 3500 or so

is there a way to stop all the advance

thanks for any help
 
Are you getting your 50 with the vacuum hooked up if so disconnect and plug the line, that should back you down to around 35-36, then see if she still pings.
 
Total advance of 50 with the vacuum advance disconnected is WAY too much. I would go no more than a total advance of 36 (no vacuum advance) and then plug your vacuum advance back in and you shouldn't have any problem. If you get pinging then set it up with a total advance of 34. If it's still pinging then cap off the vacuum port.

My small block is really too radical for 92 octane and I have to have at least 96 octane to stop the pinging. If your pinging at a total of 34 degrees total mechanical advance you have two choices, back off even more, or buy some 118 octane racing fuel and mix it with high octane pump fuel until it stops pinging.
 
Third choice, fix the problem of too much total and not enough initial.

Need to limit mechanical advance in the distributor.
 
thats the plan crackedback

got the distributor out and dissassembled thinking of a way to limit the advance
 
1978... is it a lean burn setup?
You can fill "Braze" the T slots on the outer 1/4th to reduce advance, then use a dremmel tool to evenly remove material from each side "slot" until you reach the 32 degrees mechanical advance your looking for.
 
how can you tell how much advance you have taken out without reinstalling and checking with a light
 
Here's a chart someone came up with, approximate slot length VS degrees advance

NOTICE that these figures are DISTRIBUTOR degrees, multiply X2 to get CRANK degrees

Dimensions for Mopar distributor slots, in DISTRIBUTOR degrees

Modifying advance slots
degrees / slot size
6.............. .340
7................355
8................375
9................390
10...............405
11.5 ...........420
12...............435
13...............445
14...............460
15...............475
16...............490
17...............505
18...............520
 
Braze/weld the inside of the slots. I rarely, almost never, do the outer sides anymore.

Get a Mr Gasket spring kit and put some lighter springs on it. The Chevy kit works fine.

A neat way to get the advance you put in it. Protractor or a degree wheel, grab a zip tie as pointer and tape it to the shaft tower, turn tower and note degrees. The chart above is really good.

You can also take a piece of cardbord, cut a hole in the center, slide it down over the shat, put rotor on with zip tie taped to it and mark sweep beginning and end points. Measure with a protractor or angle finder.
 
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