MSD Total timing problem

[Dennis Kelley]

Hey Guys,

I have a problem with my mechanical advance. Namely that I have the red bushing in the distributor (28degrees mech) and I am only getting 14 degrees of mechanical advance. Has anyone else had this problem Its a ready to run MSD with vacuum advance any input appreciated.

[SCOBRAC]

At what rpm are you only getting 14 degrees? If it's 2000 take it to 3200... Now what? if it's now closer to 38 total you need to change the springs to the blue or light silver or one of each. What now? If that doesn't work...

There is a provison for you to have the weights locked in, limiting the total advance. Look at the advance plate. Is the red bushing in a small hole limiting its movement? If so your distributor may be locked in. You would have had to have the distributor apart already to have this happen, it's easy to let happen. If the weights are locked in put the advance plate back in 180 degrees from the way you took it out... Your done. Verify the advance curve you like at 1000, 1500, 2000 and 3000... Done

[Dennis Kelley]

I've never hadd the dist apart. I do have the lightest springs (silver) and the red bushing. the total timing mech timing is 14 degrees at max rpm 6000. I had it on the dyno and the dyno operator and my self watched the timing curve throught a pull. I suppose I'll just have to take the dist out and see whats going on. 22degrees total timing is all I can get into the thing.

later dennis

[trularin]

How about you try for the "Total Timing" approach.

Set the RPM to 3000 and set the distributor to 32 to 38 degrees (I like the 36 degree mark myself ). Then let off the throttle. See what you have. If you have a vac advance, connect it to ported vacuum on the carb or TB. To check which port, connect a vac guage and watch for an increase as the throttle is increased.

You then might want to slowly rev her up to 3000 to 3500 and see how the curve looks. Use 200 rpm marks and ask someone to write the number down as you go.

Then you can change springs and bushings to fit, you may be limited to a short band of advance.

Typical would be something on the order of 12 to 16 in mechanical and 12 to 16 in vacuum. So, by this method you set the total ( most critical ) timing first and then back out.

Say you set this at 36. Let's say you have 14 in mechanical advance and 16 in vacuum. that means you should see something like 6 BTDC at idle.

Hey, it's an option. I'll bet if you have any CAM other than bone stock, at 14 degrees, you are having some good backfires.

[cuda66273]

We now have the MSD bushing kits in stock to give you 10-12 and 14 mechanical $15.00

www.4secondsflat.com

[powerpagers]

THE BUSHING KITS SOLVED PROBLEMS I WASN'T EVEN AWARE OF.

[Dennis Kelley]

actually the problem was an overtightened lock nut that holds the bushing on. the overtighteded nut acted as a stop. loosed the nut one turn and presto porblem solved

Thanks Dennis