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why is distributor drive gear bevelled?
Posted by: vairTer ()
Date: January 15, 2023 07:59PM

I notice that the leading edge of the distributor drive gear is bevelled. Is this to facilitate the engagement of the gear with the helical gear on the crankshaft?

I'm having issues getting a new distributor (from 123, not an original Corvair distributor), with a non-bevelled gear, to seat properly in the distributor mounting flange. There are plenty of reasons, other than the drive gear bevelling, why this could occur, but I'm trying to understand if the gear bevelling is critical to the design.

1966 140 Monza PG convertible
Ventura County, CA

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Re: why is distributor drive gear bevelled?
Posted by: RobertC ()
Date: January 15, 2023 10:07PM

The Corvair distributor drive gear is beveled - to mate with the brass gear on the crankshaft.

Your new distributor does not have the correct gear for a Corvair.

Hopefully you have not damaged the brass gear.

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Re: why is distributor drive gear bevelled?
Posted by: vairmech ()
Date: January 16, 2023 04:21AM

If the oil pump tang is not lined up the distributor will not go in. Try tuning the engine one direction or the other to let the distributor drop in the oil pump drive slot.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: why is distributor drive gear bevelled?
Posted by: vairTer ()
Date: January 16, 2023 06:30AM

Ken-

I had tried turning the engine (moved the flywheel timing notch about 1 inch in either direction from TDC), but still couldn't get the distributor to seat.

I'm going to remove the shaft drive gear and see whether I can get the distributor shaft to enter the oil pump slot. There is a possibility that the shaft endpiece is not properly bevelled either.

Thanks for the suggestion.

Terry

1966 140 Monza PG convertible
Ventura County, CA

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Re: why is distributor drive gear bevelled?
Posted by: JimBrandberg ()
Date: January 18, 2023 04:59AM

Sometimes even a correct Corvair distributor goes in a little difficult requiring a little lift up and clunk down to go in.
I don't see a scientific answer to your question as posed except I would probably agree it has to do with the life of the brass gear it mates to.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: why is distributor drive gear bevelled?
Posted by: roger65180 ()
Date: January 18, 2023 05:15AM

as Ken said you have to line up the tang on the distributor and the slot in the oil pump . And 1 in either way may not be close at all to get the line up , remember the distributor only turns half the distance that the crank shaft turns

Roger R
Madison Wi
62 ct pg turbo
65intercooled 180 4sp,autocrosser
62 Rampy

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Re: why is distributor drive gear bevelled?
Posted by: isucorvair ()
Date: January 18, 2023 08:58AM

I seem to remember there being another topic about 123 Distributor that didnt fit - had to have work done to it to make it function.


Eric P
DeWitt, IA

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Re: why is distributor drive gear bevelled?
Posted by: Seth Emerson ()
Date: January 18, 2023 11:05AM

Are the diameters of the shaft on the 123 dist the same as those on the Corvair distributor? If so, just put on a Corvair gear. They are available new!

Seth Emerson

Check my new Performance Corvair Web site: [www.perfvair.com]

Located in lovely San Jose, California

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Re: why is distributor drive gear bevelled?
Posted by: Frank DuVal ()
Date: January 18, 2023 07:25PM

Hmm, I just checked 123Ignition website and they do not list a Corvair distributor.confused smiley

Are these units modified by someone else?

Frank DuVal

Fredericksburg, VA

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Re: why is distributor drive gear bevelled?
Posted by: American Mel ()
Date: January 18, 2023 08:56PM

Frank DuVal Wrote:
-------------------------------------------------------
> Hmm, I just checked 123Ignition website and they do not list a Corvair distributor.confused smiley
>
> Are these units modified by someone else?


If I recall correctly (from terry's other posts), he is kinda acting as their prototyping guinea pig.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: why is distributor drive gear bevelled?
Posted by: vairTer ()
Date: January 18, 2023 09:33PM

yes, I am sort of their alpha-tester.


I will likely try to transfer my old original Corvair gear onto the new 123 distributor.

1966 140 Monza PG convertible
Ventura County, CA

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Re: why is distributor drive gear bevelled?
Posted by: JimBrandberg ()
Date: January 20, 2023 05:45AM

Aren't Corvair distributors very similar to other Chevrolet 6 cylinder distributors? As such wouldn't they not be made of unobtainium? Does a 6 cylinder Chevy have a beveled gear?
I seem to remember a Corvair here with a 6 cylinder Chevy distributor. If I remember right it was functioning okay but Specifications showed way too much advance. It's quite possible that I'm not remembering it right and the distributor was not in an engine but just a loose part in a box.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: why is distributor drive gear bevelled?
Posted by: Richard ()
Date: January 20, 2023 12:24PM

vairTer, a few days back you said, "I'm going to remove the shaft drive gear and see whether I can get the distributor shaft to enter the oil pump slot."

You need to start there.

>>, to seat properly in the distributor mounting flange.<<
That sounds to me like you are saying the distributor shaft tang is in the pump drive gear shaft slot, but the distributor housing is sitting proud of the dist mounting pad.

Most GM dist have a lot of axial movement (up/down slop). If you take that play out, by shimming it on the bench, without actually measuring, you can be pushing the dist shaft into the pump.

You may need to remove the upper roll pin, spacers(2) and shim. You can then check axial play and shim accordingly.

The chevy 230/250/292 dist is similar, but with some machining differences. The dist shaft and gear are corvair only. The gear is completely different, with the number, slope and direction of the teeth because the inline dist is cam driven and the corvair is crank driven. The inline 6 housing has a lower bushing, even in the HEI version.

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Re: why is distributor drive gear bevelled?
Posted by: RexJohnson ()
Date: January 20, 2023 12:25PM

The straight 6 dist is similar with some parts the same. Where the housing inters the block the straight 6 is a smaller od. The shaft is shorter and uses a different gear. I believe in the straight 6 the gear cut angle pulls the shaft down where as the Corvair pushes up. That is why the Corvair has the thrust washers just below the housing that the straight 6 does not.

RJ tools
Salem,Oregon

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Re: why is distributor drive gear bevelled?
Posted by: RexJohnson ()
Date: January 20, 2023 12:37PM

The Corvair has a lower bushing, it's called the rear housing.

RJ tools
Salem,Oregon

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Re: why is distributor drive gear bevelled?
Posted by: Richard ()
Date: January 20, 2023 05:38PM

The GM inline also has a lower bushing, for a total of 3 bushings for the dist. It's a brass bushing pressed into the block, just above the pump.

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