HEI ? for Martybose

[littleman]

You said that you zip tied the centrifugal weights to keep them out of the advance equation. Did you tie them around the circumference or over the top? How long have you been running like this, I fear that the tie could brake, and cause damage inside the unit. What are your thoughts regarding a more permanent restriction?

Cetainly makes a big difference. Thanks for your suggestion.

AL

[martybose]

You said that you zip tied the centrifugal weights to keep them out of the advance equation. Did you tie them around the circumference or over the top? How long have you been running like this, I fear that the tie could brake, and cause damage inside the unit. What are your thoughts regarding a more permanent restriction?

Cetainly makes a big difference. Thanks for your suggestion.

AL

I tiewrapped the weights around the circumference using a standard size tiewrap (as opposed to the cute minature ones). I had to slide it around a bit until I found a location that would clear the rotor. I've been running it that way for almost a year, but I don't put a lot of miles on the car. I'm not worried about the tiewrap breaking, you should see what we have used them for on the race cars!

My long term fix will probably be to limit the amount of centrifugal advance, probably by putting a stop in that moves the starting position farther out, then putting a stronger spring so that the advance doesn't start until a higher RPM. As a guess, the goal would be about half of the total advance, with it starting at maybe 2000 RPM and all in by say 3000 RPM. That would be a starting point, to be finetuned on my favorite test hill.

Marty

[Don Coatney]

It is a shame you have to do this after paying good money for an "engineered" system.

[grey beard]

I once taught in a NJ school that had a 500 hp dyno. in the floore. We played with advance curves quite a bit - they can yield instant hp when you get them right. Memory says you are right on the button, Marty - all out by 3000 rpms but this was with 10 to 16 degrees initial advance on Ford race motors - mosrtly 427's and 428's, back in the late sixties.

Wouldn't it be nice if someone with a dyno and a little savvy would develop an optimum advance curve for our flatries and let us all in the secret. It is my best guess that cenrifugal and vacuum advance cirecuits are the least understood and least correct systems on most of our vehicles. I'd love to get my hands on an old distributor machine to use on my own stuff today. Yes, you can get there with an advance timing light, and yes, I have one, but the distributor machine made adjustments so much easier and cleaner.

Any body know where one is for sale? I'll bet most of those things still left are gathering dust today, especially since modern cars don;t even use distributors any more.

[Don Coatney]

I missed the boat on buying a distributor machine a couple years back. I found this very same machine last week when I paid a visit to a new forum member here in the Boro. I ask him to sell it to me but he did not want to part with it. I am still looking for one too.

[martybose]

The clever thing that the Mopar engineers did was set up the distributor with too much centrifugal advance because they knew that you would need more throttle to go faster (say above 40 MPH) and the more throttle you used the less vacuum you would have, so as you went faster the vacuum advance would be reducing. The net effect was more advance overall at low speeds and reduced advance at higher speeds.

Marty

[grey beard]

Marty,

Are you running with or wirhour vacuum advance, now that you've neutered the centrifugal advance? What initial advance will your engine tolerate, or don't you bother to measure it? Tell us more . . .

Thanks

[martybose]

Marty,

Are you running with or wirhour vacuum advance, now that you've neutered the centrifugal advance? What initial advance will your engine tolerate, or don't you bother to measure it? Tell us more . . .

Thanks

I am using vacuum advance with the hose hooked to the intake manifold, so the vacuum signal represents engine load. I'm currently running 4 degrees initial advance, set with the vacuum advance hose disconnected and plugged.

Marty