Looking to get some more opinions. Talked to the Chris P last night about this.
I am debating on getting a new distributor from MSD that will allow me to change out the stop advance bushings to dial in my timing better. I have the distributor that came with my engine when I bought it. Not sure if it is an MSD or not. No markings. But I put my total timing yesterday at 36 degrees to where it does not advance anymore. In my garage revving the engine past 3000 I get no ping and it is crisp. Under heavier throttle I don't hear a ping but with my exhaust it is hard to tell. I have light springs which brings in my advance all in around 2400. I have my vacuum plugged. When I then checked my initial it is at like 10-11! So that means there is like 25 degrees in the distributor! That seems really high to me. Obviously if I change my initial it changes my total. If runs and idles ok at that initial. I have an adjustable Crane vacuum can. When I plug it in my initial jumps to 23-24. I have done a lot of research and have read that 383 SBC should be 14-16 initial. I thought the rule of thumb was to put in as much initial as possible while limiting your total to the 34-36 rule.
1. Should I be as concerned with the initial sitting there at 10-11 without the advance?
2. Since I am running an advance vacuum does my engine no longer care what my initial is since the advanced initial timing is in the 20's?
3. Would it be better to get an MSD Billet to where I can change the stop bushing degrees? I think there stock is 21 degrees, but the have some others. Even staying at the stock blue bushing at 21 and I set my total advanced at 36 it would put my inital around 15 or so. Then I can limit or change my vacuum can.
Just looking for some technical advice.
Thanks
-- Edited by gearlube on Sunday 27th of July 2014 10:57:04 AM
-- Edited by gearlube on Sunday 27th of July 2014 10:58:49 AM
Jon H said
Jul 27, 2014
Man, you just opened up a big can of worms!
Have you read the long post on team chevelle regarding time? If not search timing and you will find a lengthy post on it that is vey informative.
I am by no means a guru on timing, but I go by the old thoughts of 14-16 initial and total of 36-38 and I have mine all in around 2400.
This works great for me and every time I read about something "new and better", I always go back to the way it was and life is good again.
Sometimes we overthink these issues. Sounds like your car is running pretty good as is. Remember if it ain't broke don't fix it.
gearlube said
Jul 27, 2014
Yes I have read the Timing 101 quite a few times. I guess my question comes down to is it worth getting the new distributor to hit a better initial number?
Jon H said
Jul 27, 2014
gearlube wrote:
Yes I have read the Timing 101 quite a few times. I guess my question comes down to is it worth getting the new distributor to hit a better initial number?
Not if it works now. If you were racing and wanted to change for different weather, fuel, etc. then maybe. I would leave well enough alone.
Lost in the 60s said
Jul 27, 2014
gearlube wrote:
Yes I have read the Timing 101 quite a few times. I guess my question comes down to is it worth getting the new distributor to hit a better initial number?
As long as you are happy with the throttle response off idle, the initial is OK. The total is more important than initial, UNLESS the engine is sluggish or bogs off idle.
The initial with the vacuum hooked up is only that, initial at idle. Once you open the throttle plates, the vacuum drops off and the timing reverts to mechanical until the engine is at a steady rpm again.
67ss said
Jul 27, 2014
I was thinking about this last night and if you want more initial timing your distributor you have will work. You will have to block how much total it is allowing and leave the vacuum advance disconnected. I can give you the number for the distributor guy if you want to bring it to him and tell him what you want it to do, I am sure he can make it do what you want.
Looking to get some more opinions. Talked to the Chris P last night about this.
I am debating on getting a new distributor from MSD that will allow me to change out the stop advance bushings to dial in my timing better. I have the distributor that came with my engine when I bought it. Not sure if it is an MSD or not. No markings. But I put my total timing yesterday at 36 degrees to where it does not advance anymore. In my garage revving the engine past 3000 I get no ping and it is crisp. Under heavier throttle I don't hear a ping but with my exhaust it is hard to tell. I have light springs which brings in my advance all in around 2400. I have my vacuum plugged. When I then checked my initial it is at like 10-11! So that means there is like 25 degrees in the distributor! That seems really high to me. Obviously if I change my initial it changes my total. If runs and idles ok at that initial. I have an adjustable Crane vacuum can. When I plug it in my initial jumps to 23-24. I have done a lot of research and have read that 383 SBC should be 14-16 initial. I thought the rule of thumb was to put in as much initial as possible while limiting your total to the 34-36 rule.
1. Should I be as concerned with the initial sitting there at 10-11 without the advance?
2. Since I am running an advance vacuum does my engine no longer care what my initial is since the advanced initial timing is in the 20's?
3. Would it be better to get an MSD Billet to where I can change the stop bushing degrees? I think there stock is 21 degrees, but the have some others. Even staying at the stock blue bushing at 21 and I set my total advanced at 36 it would put my inital around 15 or so. Then I can limit or change my vacuum can.
Just looking for some technical advice.
Thanks
-- Edited by gearlube on Sunday 27th of July 2014 10:57:04 AM
-- Edited by gearlube on Sunday 27th of July 2014 10:58:49 AM
Have you read the long post on team chevelle regarding time? If not search timing and you will find a lengthy post on it that is vey informative.
I am by no means a guru on timing, but I go by the old thoughts of 14-16 initial and total of 36-38 and I have mine all in around 2400.
This works great for me and every time I read about something "new and better", I always go back to the way it was and life is good again.
Sometimes we overthink these issues. Sounds like your car is running pretty good as is. Remember if it ain't broke don't fix it.
Yes I have read the Timing 101 quite a few times. I guess my question comes down to is it worth getting the new distributor to hit a better initial number?
Not if it works now. If you were racing and wanted to change for different weather, fuel, etc. then maybe. I would leave well enough alone.
As long as you are happy with the throttle response off idle, the initial is OK. The total is more important than initial, UNLESS the engine is sluggish or bogs off idle.
The initial with the vacuum hooked up is only that, initial at idle. Once you open the throttle plates, the vacuum drops off and the timing reverts to mechanical until the engine is at a steady rpm again.
I was thinking about this last night and if you want more initial timing your distributor you have will work. You will have to block how much total it is allowing and leave the vacuum advance disconnected. I can give you the number for the distributor guy if you want to bring it to him and tell him what you want it to do, I am sure he can make it do what you want.