Distributor advance

[pyrojim]

When the car is idling, set the timing @ 20 degrees with the vacuam advance disconnected, raising the rpm by 400 or 500 causes the advance to go to 50, my guy says that seems way high. It's a 360 magnum, just rebuilt. Do not know what distributor is on it. Any input is appreciated.

 

[KitCarlson]

Too much something.

 

[ir3333]

..if you start 20 and it goes to 50 w/out vac advance then you are adding 30 mechanical.. that is too much!
you will have to weld the slots in your distributor to restrict mech advance to about 15.

 

[crackedback]

..if you start 20 and it goes to 50 w/out vac advance then you are adding 30 mechanical.. that is too much!
you will have to weld the slots in your distributor to restrict mech advance to about 15.

:cheers:

Spot on depending on style of distributor

 

[pyrojim]

..if you start 20 and it goes to 50 w/out vac advance then you are adding 30 mechanical.. that is too much!
you will have to weld the slots in your distributor to restrict mech advance to about 15.

Yep, that's what we're going to do. With the vacuam advance it was at 50+
I'm going to try running the initial advance down, see how it does and then weld the slots to limit the advance.
Thanks.

 

[67Dart273]

Here's a chart to give you approximate slot length vs advance degrees


Bear in mind this is DISTRIBUTOR degrees which is half of crank degrees. You original "top hat" is probably stamped with the original mechanical advance figure. Again it will be dist. degrees. So for say, 20--22 at the crank you want a slot length (below) of .4-.420

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

 

[moe7404]

man o man i sure could have used that info back in 1968

 

[pyrojim]

Thanks67 Dart. That's A Great Piece Of Information!

 

[roccodart440]

re-curve and ditch the vacuum advance. 20 initial is fine but with today's gas even 38 total is pushing it on most engines. 34-36 should work. I run 22 initial, 32 total

 

[pyrojim]

Hey crackedback. I find it hard to concentrate on what you're writing, but I love it when you post. Can't decide which of your vids I like better!!!!!!

 

[kenabody]

I recently had a hard to diagnose (and possibly unusual) problem with the electronic MP distributor that came with my magnum crate motor. The symptoms were:
1) unstable timing-timing would not stay in proper adjustment, resulting in....
2) unstable idle, poor performance, stalling, backfiring, etc.
The problem gave all the symptoms of faulty carburetion (manifold leaks, clogged jets) yet no apparent faults with the carburetor.
I went to the most apparent source of the problem-the distributor. I found that the split pin which holds the reluctor in position had worked up to a point that was allowing the reluctor to turn on the distributor shaft! I discovered this by accident while holding the reluctor and turning the distributor drive gear. Needless to say, after correcting that condition and reinstalling/retiming the distributor solved the problem.
As they say-what are the odds?

 

[pyrojim]

Got a brand new rpm air gap and Holley 650. When I got it, it was set up for the strip. Mopar m1 Holley 750. 410 gear. I wanted to bring it down a bit and don't have much experience. So I think that not only do I have to limit the advance by slot adjustment, but I think I need tighter springs as well. Advances all the way by 1500 rpm?

 

[tekslk]

Will 22 initial have starter kickback or drag?

 

[67Dart273]

man o man i sure could have used that info back in 1968

So could've I, LOL

Thanks67 Dart. That's A Great Piece Of Information!

Yer welcome, but not my credit. Found it "somewhere else."

 

[moe7404]

to: 67dart273, i have a paper factory service manual. for 1967 dart, coronet. charger. i owned a new 66 charger. if you need info send request to [email protected] did i misspell gmail? check it out. i have other factory manuals.

 

[67Dart273]

Hi moe, I have one on CD, but thanks. There's getting to be "less and less" that's 67 on mine, LOL

 

[roccodart440]

I recently had a hard to diagnose (and possibly unusual) problem with the electronic MP distributor that came with my magnum crate motor.

At the risk of offending the purists those distributors are junk in many ways. My engine builder will not build, dyno or send an engine out with one of those.

Got a brand new rpm air gap and Holley 650. When I got it, it was set up for the strip. Mopar m1 Holley 750. 410 gear. I wanted to bring it down a bit and don't have much experience. So I think that not only do I have to limit the advance by slot adjustment, but I think I need tighter springs as well. Advances all the way by 1500 rpm?

The advance on the mopar distributor in stock form is all in very early. Too early IMO. I'm not understanding why a holley 750 and an M1 intake is a strip setup? The carb is no problem and while I don't like the M1 intake (i prefer the victor jr. over it) There is no reason it cannot be used in the street.

Will 22 initial have starter kickback or drag?

Not all cars are the same. In my case the short answer is no. I can tell a difference in how it sounds starting cold vs. hot. But there is no issue. I run a digital 6 so if I wanted to I could start it at 2 degrees advanced using the 20 degree start function.