Distributor Gear Wear

[73c34me]

383 SBC. MSD distributor gear worn 180 degrees. The gear is compatible with the roller cam. Big question, tear completely down or a thorough flush, replace the gear (if the cam gear is good), cross fingers and retry.

Details:

Block and heads have been milled, distributor was shimmed up. The roller cam has an end play button. I changed the oil pan gasket and cleaned the pan approximately 150 miles ago and there was nothing of note to observe. Although if I thought the gear was wearing I would have been much more thorough in my review. The oil pass is blocked off. I haven’t drained the oil yet, but if it is clean and a filter media inspection suggest that the metal was trapped within, what next.
Assume that the motor needs to be disassembled and cleaned, etc or thorough flushing followed by fresh oil, filter and fire it up? FWIW I glanced at the oil pressure gauge almost. Simultaneous to the engine shut down and it was 60lbs.
Thnx. Jim

[Lizardracing]

High pump loads and thick oils are hard on dizzy gears.
What oil?
What pump?
What gear?

I don't trust anything. I'd take it apart and wash it with hot soapy water and bottle brushes in the galleys and reassemble.

[73c34me]

I agree with you. The reality is I don’t know when I would get to this, so it could be a long time.

Melling m55 hv
Mobil 10-30 synthetic

[BOOT]

Is the block or dist grooved to oil the gear? Did the dist have the o-rings above n below the oil passage groove?

The correct answer is always tear it down and clean it but honestly things are always wearing a bit someplace. It depends on a lot of factors, how much $ you got into this engine, the size/type of shavings, are you gonna tear it down anyway soon, are you using a vac pump or anything else that could be clogged(cooler) or harmed by the shavings, is the engine suppose to last forever or will something else break most likely. Your oil bypass is blocked so I'd prob just change the oil & filter and run it, new gear is gonna break in kinda anyway if you wanna consider that.

[73c34me]

No to “O” rings or grooves in block or distributor housing. Engine is a typical 383 with good parts and such.
I drained the oil and strained it through a paint filter. The was no visible metal shavings or dust. A magnet thru the oil didn’t show any signs of, nor was anything stuck to the magnet. The drain plug magnet had some slight metal slivers and crud’s. Nothing significant though. I cut the filter to inspect it yet as I don’t have a tool for that. I have wiped cam lobes in the past and I don’t see anything resembling that situation. I pored 4 gallons of kerosene down thru the intake, followed by 2 quarts of ATF. I will continue this but have to get more.
I ordered a premium distributor gear from Chris Straub and am converting to a slip collar on the distributor housing. I think maybe the shims (decked block and heads) contributed to a less than ideal alignment for the gears.

[73c34me]

No to “O” rings or grooves in block or distributor housing. Engine is a typical 383 with good parts and such.
I drained the oil and strained it through a paint filter. The was no visible metal shavings or dust. A magnet thru the oil didn’t show any signs of, nor was anything stuck to the magnet. The drain plug magnet had some slight metal slivers. Nothing significant though. I haven’t cut the filter to inspect it yet as I don’t have a tool for that. I have wiped cam lobes in the past and I don’t see anything resembling that situation. I poured 4 gallons of kerosene down thru the distributor hole in the intake, followed by 2 quarts of ATF. I will continue this but have to get more.
I ordered a premium distributor gear from Chris Straub and am converting to a slip collar on the distributor housing. I think maybe the shims (decked block and heads) contributed to a less than ideal alignment for the gears.

[ProPower engines]

383 SBC. MSD distributor gear worn 180 degrees. The gear is compatible with the roller cam. Big question, tear completely down or a thorough flush, replace the gear (if the cam gear is good), cross fingers and retry.

Details:

Block and heads have been milled, distributor was shimmed up. The roller cam has an end play button. I changed the oil pan gasket and cleaned the pan approximately 150 miles ago and there was nothing of note to observe. Although if I thought the gear was wearing I would have been much more thorough in my review. The oil pass is blocked off. I haven’t drained the oil yet, but if it is clean and a filter media inspection suggest that the metal was trapped within, what next.
Assume that the motor needs to be disassembled and cleaned, etc or thorough flushing followed by fresh oil, filter and fire it up? FWIW I glanced at the oil pressure gauge almost. Simultaneous to the engine shut down and it was 60lbs.
Thnx. Jim

If the gear is only worn on half of it ( 180 degrees ) then I would check the dist. shaft for a tweak in it..
if the shaft is bent or bowed while in the block there may be a misalignment of some kind you missed.

I always put the pan on last after getting the dist. checked for mesh and depth. It saves issues like this after its been run.

[Lizardracing]

I use gear marking compound to check for mesh a since I lost one 10 years ago.

[stealth]

Could be bottoming out on oil pump/drive shaft. Causes a lot of drag an wear on gear. Especially a concern without adjustable collar on distributor and milled parts.

[dwilliams]

Could be bottoming out on oil pump/drive shaft. Causes a lot of drag an wear on gear. Especially a concern without adjustable collar on distributor and milled parts.

That'd show up in the oil pump cover plate.