All in timing question.

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Shane

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I under stand total timing, I am setting up a new msd billet distributor, I'm going to go with the black bushing(18 degree advance)

My engine seems happiest around 18 -20 degrees initial. Starts nicely, and has the highest vacuum.

The part i don't fully understand is what springs to put in.

Any advice on what rpm my all in timing should be at , to test to find the right rpm would be appreciated!

Thanks

Shane
 
If you are running nearly 20 initial, 18* in the distributor MIGHT be too much. You need to figure out the two limits, that is, what the engine wants at idle, and what is safe and best power at full advance.

The springs do not affect these two points. The springs affect how quick the advance moves from initial to "all in." The engine build is what determines this, along with how it's driven.

A high stall converter, low rear gear, and mostly high RPM might even work with NO springs.

But a 4 x 4 being lugged around in the woods, or a heavier, higher geared vehicle needing to run more at low/ med RPM needs a slower advance in the midrange (more spring) to prevent detonation under heavy load, low/ med RPM conditions
 
I set the distributors in my race cars to all in @ 2000. This might be to agressive if your talking street ar or a heavy car.
 
I was worried that it maybe too much.. Do they make bigger bushings, that I could put in?

I am running an over drive 4 speed , with 4.10, or 4.11 rear gear(can't recall what one is in there)
 
What total number are you trying to hit?

If you want 36*, then 18 + 18 is good. Less than 36 and you need a bigger bushing.

You can make your own limiter bushing if you are handy with a drill and some round aluminum stock.

Most of my stuff ends up with a med and light spring, sometimes 2 mediums. I never use the giant springs that MSD's come with from the factory.
 
Hey cracked back!!

Well from your teachings a year or two ago , I understand total and inital timing, and was going to shoot for 36 total.

Should I stick in one heavy, one medium and the black bushing? Turn back my intial to 18 and see how she runs?
 
The heavy springs are death on a smooth curve in MSD distributors. The first ting I do when I get a MSD distributor is rip those garage door springs off the advance mechanism. :)

Run a max of the two light blue springs. That should get all your timing in by around 2500.

If you run a light blue and light silver it will be all in by ~2K RPM.

You got it, black bushing, and 18 initial is a good baseline. If it does ping, turn the initial back a couple degrees, not ideal, but get the ping under control. If you have it tuned at that point now, there shouldn't be any issue with the new distributor.

Didn't recognize the post without your avatar.
 
Yes, it can start pinging if it's all in too early, likely not going to be the case with the two blue springs.
 
Aren't the blue springs lighter then the heavy silver! Doesn't a lighter spring bring it in sooner?
 
If you want it in at 4K, run the heavy springs...

Look at the instructions for the distributor. It has the curves plotted for each combination.
 
i think msd comes with 2 really light silver springs and 2 heavy silver springs along with the med blue.
 
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