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Old 07-27-2021, 07:00 PM   #24
mattfranklin
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Join Date: Dec 2011
Location: Moraga, CA
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Re: Can't get distributor to lock down.

Intake issue? -- Maybe it just needs a new tunnel ram. J/K.
Seriously, what a pain.

As long as the shaft isn't bottoming out and keeping the bottom of the dizzy flange from seating on the intake...

There aren't many things left. Surface roughness (on the intake, dizzy upper and lower flange surfaces, and clamp) and clamping force are what you need to keep it from twisting. Are any of the surfaces more shiny and polished (and oily) than normal? Rough cast surfaces can be pretty grippy compared to smooth machined or worn surfaces.

I remember an old engine once that was pretty each to move just by tapping the distributor diaphragm cannister back and forth. It had a really shiny top flange surface where the clamp was supposed to dig in, and I think the clamp was really smooth too, and it had a film of oil on it. Maybe you just have the perfect storm of all of these things adding up against you.

Good luck and keep us posted.

EDIT: Is the clamp right-side up? Are there sharp corners on the steel clamp to dig into the aluminum flange of the distributor?

EDIT2: Note sharp corners on stock clamp. https://www.summitracing.com/parts/n...make/chevrolet
I've seen some aftermarket clamps have rounded bumps to do the clamping. Nice for not scratching show-car polished billet distributors, but kind of lacking in the grip department.

EDIT3: Check the stars and comments on that Summit link. They guys were using the stock clamp with a stud to solve their problems.

Quote:
Originally Posted by grubsster View Post
Cadillac_al, yes it is a new edelbrock installed by the builder when they assembled the engine. I am growing more suspicious of the intake. I guess this is why I've been chasing the timing issue for so long.

Crossfire, thanks. Yes, I have tried multiple distributors and clamps. I even pulled one out of an old truck yesterday just to see if it would lock down. None have worked out.
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Last edited by mattfranklin; 07-27-2021 at 07:09 PM.
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