I am trying to set up my 427. I have a question on timing. I am running around 10:1 compression with a comp cams EX 285 cam. My carb is a SA 870. the ignition is a MSD 6al with a msd distributor part number 85551 (mechanical advance)I put a timing tape on the dampener and used a regular timing light. I set the timing at what I thought was about 33* at around 1000 RPM. When I use a dial back timing light and set it to 33* I am no were close to the TDC mark being at 0 on my pointer. What am I doing wrong? I also think I may have a rich idle circuit but I want to get this fixed first. car seems to idle best with the screws backed out 1/2 turn.

Sorry if the timing question has been asked a billion times, I always read to check it with out the vac hooked up but I don't have vac to unhook.

Also I would like to get a vacuum gauge to test engine vacuum. any good ones that wont break the bank. I am thinking with the big cam I may not have the vac to run the brakes.

there are a ton of threads for timing.Do a search

A good start is 18* intitial (vacuum advance unpluged) then 18-20 mech all in by 3000 for a total of 36-38.All motors are different you just have to find what yours wants but this is a good starting point.Other will agree

If you have not changed your distributor from stock settings it should be providing 21* mechanical advance and if the stock springs (Heavy Silver) are in it you won't see full advance until 4000rpm. I doubt that the amount or rate you have will provide best performance. The least amount of mechanical advance that distributor can provide using the bushings provided is 18* and that would be with the black advance bushing installed. That would allow you to set the initial timing at 15*. If you were to use one of the stock heavy silver springs with one of the the light springs that is also silver in color your mechanical advance should be all in by 3000rpm. I think this would be closer to what you needed but it would all be trial and error and you would need to insure that the engine didn't detonate at any time using these settings.
Mike

I use the Light silver and the heavy silver, along with the red bushing. were do I set it at? maybe a call to MSD is in order.

ok sitting thinking about this, I think I know what I am doing wrong.

I am a idle were ever the timing is I think is my initial.

I am idling at 1000 rpm I have the timing set at 33-34* I need to back that off correct? I do not have a vacuum advance distributor so that part does not apply to me.

at 3000 rpm I should be fully advanced ad that is were I should have 33-34* correct?

ok sitting thinking about this, I think I know what I am doing wrong.

I am a idle were ever the timing is I think is my initial.

I am idling at 1000 rpm I have the timing set at 33-34* I need to back that off correct? I do not have a vacuum advance distributor so that part does not apply to me.

at 3000 rpm I should be fully advanced ad that is were I should have 33-34* correct?

Exactly. And you mentioned the timing tape you applied to your damper. Did you simply align it with the zero mark without confirming its accuracy or did you use a piston stop (or simialr method) first? I'd hate to see you chasing your tail if you don't truly know where zero is.

Exactly. And you mentioned the timing tape you applied to your damper. Did you simply align it with the zero mark without confirming its accuracy or did you use a piston stop (or simialr method) first? I'd hate to see you chasing your tail if you don't truly know where zero is.


The timing tape was palced at Zereo. The machine shop Set that for me when the rebuilt the Engine. He told me that he set it up so that it was an acurate mark.

Did you recieve the instructions with your distributor? Here they are if not.
http://static.summitracing.com/global/images/instructions/msd-85561_8547_frm22016.pdf