Tuning a New Distributor, Help or Suggestions Please
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,414
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From: NC
Tuning a New Distributor, Help or Suggestions Please
I bought a new tach drive HEI distributor off of eBay for my 350, has an Edelbrock intake, carb and very mild cam.
I’ve installed it and can not get the 36 deg setting described in the “Info on Timing - long post!”.
I bought a spring and weight kit from Advanced Auto so I have a lot of different combos that I tried. It just seems that the system is only able to achieve 24 to 26 deg’s of advance. I tried light springs but that makes the mechanicals come in at idle and the advance reached 40* at 3000 but will continue the higher I rev it. With a light spring and one that looks like the next step higher in strength spring gives me the best, none or very little at idle and around 26* at 3000. I have an extra exact set of weights and center piece and I did some grinding hear and there to try to modify the weight geometry and I still can’t get it to come all in at the recommended RPM. It seems they are designed to hit a wall so to speak but clearly they could advance more until they hit the pin stop under the weights.
My initial is set at 8* at 650 rpm’s, that is what is called for on the sticker in the engine compartment.
Is there another spring/weight kit that will help me out or do I just set it up to get me 36 and not worry about the initial? It seems to run okay, maybe.
Bill
I’ve installed it and can not get the 36 deg setting described in the “Info on Timing - long post!”.
I bought a spring and weight kit from Advanced Auto so I have a lot of different combos that I tried. It just seems that the system is only able to achieve 24 to 26 deg’s of advance. I tried light springs but that makes the mechanicals come in at idle and the advance reached 40* at 3000 but will continue the higher I rev it. With a light spring and one that looks like the next step higher in strength spring gives me the best, none or very little at idle and around 26* at 3000. I have an extra exact set of weights and center piece and I did some grinding hear and there to try to modify the weight geometry and I still can’t get it to come all in at the recommended RPM. It seems they are designed to hit a wall so to speak but clearly they could advance more until they hit the pin stop under the weights.
My initial is set at 8* at 650 rpm’s, that is what is called for on the sticker in the engine compartment.
Is there another spring/weight kit that will help me out or do I just set it up to get me 36 and not worry about the initial? It seems to run okay, maybe.
Bill
Le Mans Master
Joined: Jan 2006
Posts: 9,192
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From: Boca Raton Florida
Reread Lars' paper, I believe he calls for 12* or so initial, that will get you part of the way there. I think I remember seeing something about stop bushings in there. With the light springs and the correct stop bushing you should get there
Race Director
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Not sure what all is in that kit....but the general idea is to install the larger bushing in it to limit total advance, then use the lighter springs to bring it in quicker. You pretty much always want to bump initial up higher than stock.
Depending on combo, 12* would be a minimum probably, and some more radical deals will like 20-30* initial!! Since most of the ones I deal with have some cam in them..I'm usually setting them in the 15-18* initial at least...then limit total with the bushings/slots.
You pretty much have it right...set your total at what you want...34-36* or whatever..then see what the initial is. The total is what you have to *work back* from. That's all going to be using the bushing and slots..then you use the springs/weights to control how fast it comes in.
JIM
Depending on combo, 12* would be a minimum probably, and some more radical deals will like 20-30* initial!! Since most of the ones I deal with have some cam in them..I'm usually setting them in the 15-18* initial at least...then limit total with the bushings/slots.
You pretty much have it right...set your total at what you want...34-36* or whatever..then see what the initial is. The total is what you have to *work back* from. That's all going to be using the bushing and slots..then you use the springs/weights to control how fast it comes in.
JIM
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
24 degrees is normal for these units. To get to 36 total you need to set the initial at 12 to 16 BTDC. You may even want to install a limiter bushing to limit the centrifugal advance to 20 degrees allowing you to run the 16 initial.
BigBlockk
Later.....
BigBlockk
Later.....
Instructor
Joined: Feb 2006
Posts: 105
Likes: 0
From: Houston Texas
I just went through the same issue with my new Accel HEI. I used the Mr. Gasket Curve kit #928G found at most auto parts stores. Lar's recommendation. Use the two gold springs in that kit and the curve falls right in. I ended up setting my initial at 17 degrees to get my 36 total. I did not touch the weights or bushings. This tuning has given me the best idle and strongest performance since I owned the car.
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
