Distributor Gear Odd Location for Dimple?

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Feb 13, 2016 | 04:54 PM

wheatpj

Thread Starter

Racer

Joined: Jun 2009

Posts: 409

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From: St. James, NC

Distributor Gear Odd Location for Dimple?

I'm changing the distributor gear (to a melonized version part # 10456413) to accommodate the roller cam in my new engine. The distributor is a breaker-point version (with chip installed) that I got from one of the Corvette vendors and used for about 2 years in my numbers matching engine. Look at location of the dimple on the gear that came off the distributor (left). I thought the dimple was supposed to align up with both the hole for the roll-pin and the rotor. The dimple for the old one aligns up with the rotor, but not the hole. The dimple for the new aligns with the hole, but obviously won’t align up with the rotor; same side, but not perfect alignment. The hole for the roll-pin appears to be drilled in the same plane to the gear for both. I sort of think it should be okay. Is this a problem?

Feb 13, 2016 | 06:19 PM

DUB

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From: Charlotte NC

I do not think that this 'dimple' is any issue at all. AS far as I know as this dimple is for is to give a person a reference...so if the gear was removed...it can be installed back on CORRECTLY and not installed 180 degrees out.

AND BY LOOKING at the hole for the roll pin...BOTH gears appears to have the hole for the roll pin in the same location in regards to the space between two gear teeth on both gears.

The only problem with putting a gear on 180 degrees out is that the rotor button on the distributor may not be in the exact same spot as when the distributor was removed.

DUB

Feb 13, 2016 | 07:29 PM

bluedawg

Safety Car

Joined: Jan 2009

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From: anchorage ak

I don't think it will be an issue, my composite gear came with out a dimple.

Feb 13, 2016 | 07:31 PM

Mooser

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Joined: Apr 2011

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From: North of Toronto - Ontario

opps, I agree with DUB, someone else snuck in
The dimple just marks "this side" or "that side" since the number of teeth is odd (14 deg or something)
M

Last edited by Mooser; Feb 13, 2016 at 07:32 PM.

Feb 13, 2016 | 08:38 PM

redvetracr

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Joined: Aug 1999

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From: WI

see how the dimple side splits two teeth? on the other side the hole lines up with the tooth, probably a different supplier.

Feb 13, 2016 | 10:39 PM

wheatpj

Thread Starter

Racer

Joined: Jun 2009

Posts: 409

Likes: 3

From: St. James, NC

Quote:

Originally Posted by DUB

That's kind of what I thought, dimple there to keep you from installing the gear 180 degrees out of phase. I just never saw a dimple located off center from the hole. Weird thing is that it aligned up with the prong on the rotor. I have it installed now, dimple side rotor side, so I should be in phase.

On the other side of the gear, the tooth splits the hole. I think I heard if the gear is installed 180 out of phase, it will charge the rotor's alignment 6 degrees.

Thanks everyone for the help and peace of mind..

Feb 15, 2016 | 04:51 PM

Tom454

Le Mans Master

Joined: Apr 1999

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From: Raleigh North Carolina

I have 3 Corvette distributors on the bench right now...
1966 327... tach drive... dimple offset from pin, dimple lines up with rotor tip
1970 454... tach drive... dimple offset from pin, dimple lines up with rotor tip
1987 350... HEI... dimple lines up with pin, dimple lines up with rotor tip

Feb 15, 2016 | 08:59 PM

wheatpj

Thread Starter

Racer

Joined: Jun 2009

Posts: 409

Likes: 3

From: St. James, NC

Quote:

Originally Posted by Tom454

The gear on left is from a tach drive distributor used in my 1971 454. I'm going to operate under the assumption that the dimple denotes nothing more than the 180 phasing for the gear installation. The plane of the gear teeth to the pin hole look the same.