[quicksilver97ta]

For my points distributor. I wanted to set this up as a ready backup for my aftermarket distributor but I wanted to have the mechanical and vacuum advance limited the same. Unable to find any advance curve kit as I wanted the new bushing I decided to make my own limiter, an adjustable one. No drill press, just a hand drill and a steady hand. Peened the threads and it's not going to move without alot of effort so I don't think its going to move on it's own. This mod and the accel adjustable vacuum advance and I’m all set. Just thought I’d share.

[shaker455]

Very clever and I like your idea!

Do you have enough wall thickness to support that size set screw?

Looks like the plate buldged a bit?

Your pivit pins look worn.

[quicksilver97ta]

Thanks Jeff! Where it's thin, it's pretty thin, I think there is some bulging at least where the hole is started. But, it’s steel, and the rest of the plate on the other side of the slot is solid, and there is really next to no load on it. I sure have more confidence in this than the long gone original bushing. It’s tapped 4–40 which is the smallest in my set and the smallest of this fastener type at Ace and coincidentally accepts the smallest allen wrench in my set at .050. I can access it under the hood by just pulling the rotor.

[Tom Vaught]

You probably only had access to certain Allen Head screws at your location.

There is a very nice 4-40 thread set screw that would give you more meat in the plate. A "stop" is a "stop"

I will have to try and do one myself. Excellent Idea.

Tom Vaught

[Half-Inch Stud]

...i used to insert a ball bearing ball into each pocket there. Was a great solution for 1 HEI. Not a solution on any of me HEIs since.

[Stuckinda60s]

It is a great idea!

I would use a much shorter screw, though. I always try to keep rotating imbalance, and its inherent stress, to a minimum.

[quicksilver97ta]

Its a 1/2" long, the shortest one on the shelf. It's actually just started threading in the pic and doesn't stick out that much once installed. I'll snap another pic or two when I pull the distributor to drop in this new accel unit. Probly after work today. Glad you guys like it.

[Kenth]

Cool ide´a.

But i don´t see no real need for this?

[quicksilver97ta]

Originally Posted by Kenth

Cool ide´a.

But i don´t see no real need for this?

That screw goes through the plate to that slotted hole. In these pics the distributor shaft is raised up so I can work on this but it slides down and that rusted, pitted looking pin above rests inside that slotted hole. That is the limit for the mechanical advance travel. A bushing is supposed to go over that pin and simply make it ‘fatter’ and take up more room allowing less travel than the pin alone. The factory used a nylon bushing and aftermarket kits use metal bushings of different sizes allowing different travel limits. I didn’t have any bushings.

Limiting the mechanical advance alows me to set the base timing higher without having more total than I want.

[Stuckinda60s]

You can take a couple of nuts and lock them against each other. Than grind the end off and run the individual nuts off to chase the threads. Make sure you bevel the ends so it will start threading in easily when you're done.

[Sun Tuned]

Works well, and it is a neat idea.

Kelly Davis owns the patent to it way back in 1977 though. The original iteration of that idea was implemented with a round hole and a spring steel roll pin.

Try some blue loctite...easier than nuts and such.

It will allow you to easily cut to the chase without dismantling the rest of the world though. However when you find where you want to be likely you'll never change it again though.

Will work light years better than the different size bushings like on a MSD for reasons I will not discuss.

Good work though.

Now get you an old set of points and strip the screw adjustment mechanism off of them and tack the assy onto a vac adv cannister and you'll have you a live bona fide adjustable vac adv cannister way more better than those sorry aftermarket ones they have been selling for 30 years.

[quicksilver97ta]

Thanks Suntuned!

[quicksilver97ta]

Here it is with about a 17-18 advance limit. That is some thread locker on the threads.

[gearbanger]

I would probably do the same procedure to the other side of the distributor shaft for balance as well. I would say that set screw spinning at 3000 rpm would wear on the dist shaft bushing pretty good.

[quicksilver97ta]

I think its close enough to the center and weighs so little that its affect is minimal. It would be better to remove more material on that side of the plate in addition to the hole I drilled. But then if I removed material from the edge it would be less because its further from the center.

[rohrt]

Thats about the best idea I have seen in this forum in a long time.

[tc]

Excellent idea and nice drilling! Might have to copy that. Good to see another do-it-yourself-er.

[frankyboy455]

Originally Posted by Sun Tuned

Now get you an old set of points and strip the screw adjustment mechanism off of them and tack the assy onto a vac adv cannister and you'll have you a live bona fide adjustable vac adv cannister way more better than those sorry aftermarket ones they have been selling for 30 years.

Hey Suntuned, I'm trying to figure that out and just can't. Can you go a bit further on that ? God I love the info we can find on that forum...

[Stuckinda60s]

Originally Posted by Sun Tuned

Now get you an old set of points and strip the screw adjustment mechanism off of them and tack the assy onto a vac adv cannister and you'll have you a live bona fide adjustable vac adv cannister way more better than those sorry aftermarket ones they have been selling for 30 years.

I can't understand how the adjustment would be for anything other than the limit. The adjustable units adjust the cut-in point, don't they?

[quicksilver97ta]

Originally Posted by frankyboy455

Hey Suntuned, I'm trying to figure that out and just can't. Can you go a bit further on that ? God I love the info we can find on that forum...

Yup, I've re-read that several times too and not sure what is described. Been meaning to ask but just busy.