Yesterday I went into my distributor to see what I had for mechanical advance, what springs. I found that I had the 13L advance arm. I also noticed that the distributor guy had welded in a stop before the full travel, limiting the advance to 8* or 16* mechanical. Along with my initial setting of 16* advance, I have a total of 32* advance. What surprised me was that he had only installed a spring on one side. Has anyone ever heard of that?

I was trying to get more pep out of the engine and wanted a quicker advance. I found the DuraSpark advance kit (Mr. Gasket 925 D) very limited with only two springs. Fortunately, I had a GM kit as well. So I did what Gofastforless recommends on his site: use a light spring on one side to give quick advance, and install a heavier spring on the opposite side, and install it with a bit of lash, so it allows the small spring to open quickly before the big spring is activated. The result was a bit more pep off the line, no detonation, no ping. Happy ending.

I came away from the project chuckling about how barbaric the procedure was, bending a mounting arm to apply tension to a spring, shoving a screwdriver blade between the coils of a spring to make the spring longer so that it has some lash (free play). Then I realized that in this computerized world, how refreshing it was to make changes in real life, and not into a keyboard. (I know that in a perfect world the distributor advance would be tested on a Sun dizzy machine, but I, like most backyard mechanics, was using the seat-of-the-pants method.)

 

You could probably go to 36 or 38 mechanical with no problems if you can get it to come in correctly. I would go out now and turn it up a little at a time until you hear pinging then back it off and see where you're at. your initial may be high enough it kicks the starter , at which time you can either back it off a little more or preferably back it off and increase your mechanical back to the peak.

What is your vac advance doing now all in with the mechanical ?

 

I used to spend a lot of time on older driver swapping different dist cams and springs. Adjusting vacuum advance. No machine just road test, was everyday ride anyway Easy to back up if you go to far and only do one thing at a time. Gave a buddies oldest son a ride to the other place one day, he never said anything thing but later he asked his dad "how can he make a truck start that fast, he just touched the key and it was running". I took it as a compliment but then remembered the son was raised on bow ties.

 

Hey sixpack. I need to degree my dampener. At 14* advance my timing mark is at the edge of the index. With the 300 there is only a thin lip, about 1/8th of an inch, on which to put degree tape, so that is out of the question. The only thing I can do is to place marks on that thin edge. I haven't gotten around to that, so that explains why I'm not certain of the total v.adv. After 14* I'd be guessing.

My combination of a lite GM spring and a stronger Ford specific spring is working fine. Thinking about buying a dial back timing light.

 

Buy a dial back, you'll never regret it. good ones used to be expensive but i think now days a decent one is pretty affordable.

 

Hey sixpack. I was shopping online for a dial back, but found that they are difficult to find if you need it to be multi-spark compatible as well. Then I googled the combo, dial back/multi-spark, t. guns, and found that MSD recommends charting your advance the old-fashioned way with marks or tape on the balancer. They say that their capacitator ignition box emits a signal that can throw off the dial back guns 4-6*. So, I guess I'll just crank the engine around by hand, and place a mark every 10*. Thanks.

 

I had a craftsman one that worked on everything i tried it on until I dropped it and broke it. now I have a Snap On one that works on everything as well.

I see no reason anything would mess up a dial back anymore than a standard light, but I can't say for sure.

 

A single spring ordinarily should be a lot snappier than two springs. Was it a heavy or medium or?? If he had it down to a specific curve it should work. All that is really needed is a standard timing light and a timing tape on the balancer that goes out to 50° or so.

I never tried a single spring alone because I didn't want to make a career out of curving the distributor, they are a pain to keep de-installing and re-installing, it also seemed to me if a single spring broke or stretched out and pranged that would complicate things. Not a show stopper but a pita on the side of the road at best.

The heavier spring in factory distributors always has a bit of looseness or lash, it gets taken up for a period of time before both springs start acting in unison.

 

Unless the tape is for the exact circumference of the dampener the light will be more accurate even in the event it is slightly messes up by the ignition.

Not that it really matters that much, there is no exact known perfect setting for any particular engine you have to find it. the light just gets you in the ballpark and allows you to return to the settings you established.

Whichever method you choose the first step is to see where you're at now and then decide how to improve it.

 

Well, I will try to get around to marking the h.balancer. Right now I'm running an initial 15*. I think this relatively large cam likes the advance. I'm going to bump it up a couple of degrees and see if I get any pinging. The reason for the interest in the t.curve is due to the engine/cam swap. I had a really torqey rv cam that killed everything off the line. With this cam I lost that bottom end, and with an I6 that's really all you have. So, I've been trying to reclaim a bit of that pep. I've been toying with the idea of either swapping my rear dana 60 with 3.31 gears to a rear with 3.74 gears. Either that or build another engine with a smaller cam. We shall see.