What springs and advance stop bushings are you guy's using in the MSD pro billet distributors?
This is a race only vehicle!This is a new one and it has the heavy silver springs installed that give the slowest advance curve.
Thanks Mike

Mine is locked out

i use the lightest springs and the biggest bushing. i think it is the black one.

I use the middle bushing but use modified MP springs non of the MSD ones are as light as I like!

Black busing with the lightest spring, set timing at 18 degrees initial with 34 degrees total

I use the lightest springs and one of the FBO bushes, 24 initial, 34 total.

Black bushing lightest springs. Makes for easy starts and all advance in by 2,000 rpm.

AED in Virgina sells more Holleys than anybody--they always tell customers with a hot rod to do the black bushing and two lightest springs--That combo will work with anything from a small cam to a 750 roller--perfect initial and then all in fast--4 speeders may want a tad different with one lightest and one blue but hey...that has always worked good for us--The two heavy jobs they send them out with won't work with anything--WHO at MSD thought that up? Oh well...at least they have a JOB

black bushing, 1 light silver and 1 light blue spring. 2 light springs will let the timing raise and lower at idle.

What exactly do the bushings do???
Mike

I've had a dozen calls in the last couple of days on this thread, we've been making these bushings for at least 8 years now.

So here's the info from our website:

MSD distributors come with 3 Advance limiter bushings with the largest one being 18* so when installed it will give you 18* of mechanical advance. If you trying to total the engine at 36* you would simply set the idle timing at 18* and this bushing will allow it to advance another 18* to bring your total to 36*.

Here's the issue, as most of you have already discovered to get a clean crisp idle out of your tune up and to make the carb adjustments respond to your tuning your performance engine wants more initial timing.

MSD will tell you to lock it out at 36 and buy one of their spark retard units ($179.00) so you can get it to crank over at 36*. We 100% adamantly disagree with this ridiculous solution designed to bleed your wallet. You motor may like the 36* all the time but in most applications it will cause over heating and detonation issues at low RPM high load.

By simply swapping out the black 18* MSD bushing (or other MSD stock bushings provided) and inserting one of our 10* or 14* bushings it will allow you to set you idle timing at 22* or 26* and not allow the timing to exceed the desired 36*.

Then run a heavier spring so your timing mark isn't jumping around when your trying to set it. Too light of a spring will allow the weights to bounce off the stop and cause the timing mark to go crazy when your trying to set your timing. If your running a 3000-4000 or bigger convertor there is no need to bring the timing all in until just below the stall, you won't load the motor until the convertor locks anyhow so there's no performance gain to had in running your distributor all in at 2000 RPM with a 4000 stall convertor...think about it.

Big cams bleed off cylinder pressure allowing you to run big initial timing numbers this will really help you get quick clean starts, we want the motor to have as much initial timing as possible without kicking back or dragging down the starter and at the same time still cranking over easily.

From our experience I will guess that 50% of you guys out there are having issues, either you purchased a Pro Billet non-vacuum distributor for an engine that needs a vacuum advance, you can't get enough initial to get a clean idle or you've been reading MSD instructions and you've got the vacuum line hooked to the ported vacuum instead of the constant. We can help you with all of these issues, not only the right parts if needed but real tech advice from professional people who will take to time to explain to you why changes may be needed to obtain the perfect tuneup.

Please do not PM us, use our direct email or call for more information tech@4secondsflat.com