Prestolite Distributor questions

stevieb49829 · Nov 25, 2022

I'm working on the distributor for my F-162 Continental 4 cylinder. It has a lot of slop, but not in the main shaft/bushings. They are .002-.003 clearance between the shaft and bushings. The slop is in the spiral-cut upper shaft that the centrifugal advance pivots on. There's way too much wear on that shaft, so the advance mechanism can cock back and forth enough that the rotor rubs up against the cap contacts. I've been looking for a NOS shaft, but a shaft for this Prestolite IAT-4405 distributor does not seem to be available. Any help finding a shaft would be appreciated. I'm thinking of building up the shaft with brass brazing and turning it down to closer tolerances. Would that work?

This distributor had a vacuum advance on it at one time. The plate pivots well. Is it worth scrounging up a vacuum module for it, in a MH 101 Jr? Right now it has a chunk of copper wire holding it in a fixed position.

Richard G. · Nov 25, 2022

If it were mine, I would build it up and turn it down just like you said.

Janicholson · Nov 25, 2022

Reaming the hole to a standard size first is warranted. The interior of the cam shaft hole is likely as worn as the shaft it rotates on. Building up the spiral shaft to that size then fitting it is great. .001 there would be my choice. Then cleaned, and a grease dab to keep it functional. Jim

Dieseltech · Nov 25, 2022

The MH 101 JR does not need the vacuum advance, and the original Auto Lite distributor did not have one on it.

Steve@Advance · Nov 25, 2022

I would look at reaming the ID big enough to press in a bushing, then turn the shaft to fit the bushing bore. That would be easier than trying to build it up.

It is critical to get the cam to run true in order for the points gap to be correct. An electronic conversion is more forgiving of a less than perfect distributor.

As for the vacuum advance, it is not needed, just something else to try to find, and chances are the diaphragm will be dried out and not last if you did find one. I would find a way to securely lock the breaker plate and be sure the rotor is timed to fire when it is aligned with the cap terminals. The breaker plate must also be grounded, be it with a ground wire or a mechanical attachment.

Janicholson · Nov 25, 2022

Also a good idea. Jim

wore out · Nov 25, 2022

(quoted from post at 15:22:19 11/25/22) Also a good idea. Jim

As a side note to this, I think the O.P. will find that both of the parts are EXTREMELY ''hard'' steel.

The Delco equivalents for sure are!

stevieb49829 · Nov 25, 2022

Steve, the breaker plate is screwed to the distributor body on two sides. I originally had a dead short of my points, and found the rivets holding the isolated side of the points were contacting the mounting plate. I stuck a piece of plastic between them and fixed it, but when I tore it down this time, I found the jury-rigged copper wire replacing the vacuum canister was too short, allowing the swivel plate to turn too far into the mounted plate causing the short. I'll fix that with a better solid attachment of the two plates. Then I won't need the plastic fix.

stevieb49829 · Nov 25, 2022

Thanks, DT. I also have the Autolite off my parts 101, without a vacuum advance, so I didn't know if it was worth it or not. I'll fabricate something to plug the slot, and at the same time hold the advance plate in a fixed position.

Jerry/MT · Nov 25, 2022

There are lot of distributor rebuilding places out there. Google distributor rebuilders. You maybe able to find the pars you need.

Prestolite Distributor questions

stevieb49829

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Richard G.

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Janicholson

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Dieseltech

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Steve@Advance

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Janicholson

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wore out

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stevieb49829

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stevieb49829

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Jerry/MT

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