HEI Distributor
Thread Starter
Instructor
Joined: Jun 2006
Posts: 146
Likes: 5
From: North Brunswick New Jersey
HEI Distributor
Does anyone know what I can expect in the way of centrifugal degrees on my '79 HEI? I rebuilt the dist. with the recommended kit with the springs so that it comes on real nice and smooth before 3000RPM, only problem is, it only has about 12 degrees of advance centrifugally, which would put my stock '79 L48 at 24degrees at idle, which it won't do. Do the stock weights add more range than these aftermarket weights or is the dist. made with less range on the smog motor than normal? Can I still obtain the original plastic bushings for the stock advance weights? Do I have to modify something for a greater advance range? Thanks in advance(no pun intended)
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
Originally Posted by Blue79
Does anyone know what I can expect in the way of centrifugal degrees on my '79 HEI? I rebuilt the dist. with the recommended kit with the springs so that it comes on real nice and smooth before 3000RPM, only problem is, it only has about 12 degrees of advance centrifugally, which would put my stock '79 L48 at 24degrees at idle, which it won't do. Do the stock weights add more range than these aftermarket weights or is the dist. made with less range on the smog motor than normal? Can I still obtain the original plastic bushings for the stock advance weights? Do I have to modify something for a greater advance range? Thanks in advance(no pun intended)
Don't use the weights in the aftermarket kits - they're no good.
Yes you can get the little nylon bushings for the spring posts. They might come in the advance kit- Mr Gasket 928G or 929 - not sure though.
Be more concerned with your total timing than your initial. With vacuum can. hose disonnected and port plugged , you should have total timing around 36 total.
Le Mans Master
Joined: Apr 2005
Posts: 6,339
Likes: 416
From: Seattle Area WA
Use the stock weights, also these guys have some nice HEI parts:
http://www.kendrick-auto.com/ignition.htm
http://www.kendrick-auto.com/ignition.htm
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
Make the weights are moving freely. Lubricate all moving parts. Set total timing first 36 degrees at 3000 rpm. Then check to see were its at when it idles. It should be around 16 or so. Vacuum is disconnected and plugged for timming readings
Did you shim it?
Did you shim it?
Thread Starter
Instructor
Joined: Jun 2006
Posts: 146
Likes: 5
From: North Brunswick New Jersey
Yes, thank you, I did shim it as per forum directions - .010 " - .015" I believe, and lubed it and used the soft springs from the aftermarket kit so it all came in just below 3000RPM. I also rubber-banded the weights in to set initial time so I could determine how much advance the distributor could deliver, which I checked with a dial-back timing light. Using the advance weights from the aftermarket kit, I could only get 12 degrees of centrifugal advance(vac line disconnected and plugged). So, when setting advanced timing at 36degrees, the timing only came back to 24 degrees, which the motor does not like or want to idle. Since the factory initial setting is 4 degrees, does that mean the stock centrifugal weight unit could deliver 32 degrees of advance? Or did the factory have total centrifugal at some other setting below 36? Will I gain a significant amount of degrees advance if I rebush the old weights and use them? Is 36 degrees centrifugal advance too much for a stock '79 L48 engine? The vac can has 15 stamped on the bracket, which I interperet as 15 crankshaft degrees?
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
Originally Posted by Blue79
Yes, thank you, I did shim it as per forum directions - .010 " - .015" I believe, and lubed it and used the soft springs from the aftermarket kit so it all came in just below 3000RPM. I also rubber-banded the weights in to set initial time so I could determine how much advance the distributor could deliver, which I checked with a dial-back timing light. Using the advance weights from the aftermarket kit, I could only get 12 degrees of centrifugal advance(vac line disconnected and plugged). So, when setting advanced timing at 36degrees, the timing only came back to 24 degrees, which the motor does not like or want to idle. Since the factory initial setting is 4 degrees, does that mean the stock centrifugal weight unit could deliver 32 degrees of advance? Or did the factory have total centrifugal at some other setting below 36? Will I gain a significant amount of degrees advance if I rebush the old weights and use them? Is 36 degrees centrifugal advance too much for a stock '79 L48 engine? The vac can has 15 stamped on the bracket, which I interperet as 15 crankshaft degrees?
You need to use the originals weights from the factory dist. Aftermarket weights are causing the problem you are having.
