Distributor gear.
 

What would cause a gear to wear off half the teeth? It's a roller cam and it had a composite gear.

Which half wore off? :D

What oil pump,80lb pumps are gear killers.Tom

A new cam can do that.

How old is the gear? Had it happen to mine last year

I don't race, but I built several high performance engines for street cars over the years. H-O Specialties used to sell a set of galley plugs, and the one inside the block had a hole drilled into it to lubricate the distributor get.

I never was sure if that was needed or not for a street car. Does anyone still do that?

Yes, this was something I specifically requested my shop to do when building my engine.

The gear had some dyno pulls and about 10 runs on it. I have the oil hole at the gear. It's a 80lb pump from Butler.

Get rid of the 80lb pump, use galley plug with small hole to oil gear (.040-.060), make sure there are no burrs/shape edges on cam gear and going racing.

New cam? Did you check the gear on it for any sharp edges?

Did you break in the new cam with a bronze gear? It will soften the edges than put the composite gear back on.

Yes it was a new cam. No I didn't break in the cam with a bronze gear. What's wrong with the oil pump?

It takes a lot of power (stress) to turn a 80 psi pump. Maybe the gear isn't up to the task. Hook up a drill to the pump, spin it and you will see how much power it takes.

I have had a BOP gear for 7 years with a 80 psi pump with no problems...

Why did u pull the dizzy?

I had a composite gear fail once, but only after several years' service in one engine and then being moved to a new block and camshaft. We think it was the move that did it. It showed no sign of wear when we reused it, but definite signs of wear after the failure. I would suspect burrs on the the cam before suspecting the difficulty of turning an oil pump. Incidentally, we didn't use a bronze gear for break-in either time, though it certainly wouldn't hurt.

Jim

Charlie,go by a lottery ticket!

We pulled it out because the motor died.

Mine has well over 1000 runs, in two different short blocks, and 80 lb pump

BOP gear and 80 psi pump in mine too. Only about 1500 miles and about 100 passes and all is well.....so far.

Guys,when the factory used a 80lb pump the used a cam with a smaller gear and used a larger gear on the dist.Engineers do thing for a reason!That was with a iron gear also.Tom

Although street only no issues with about 5200 miles. BOP gear and 80 psi pump, engine made peak power on the dyno at 5900/6000 rpm. Can anyone provide actual real world comparison data between the two regarding power (stress) to turn a 80 psi pump ?

.

I understand this is the 'race' section, but for interest I found this....

Common hobbyist concerns when using an 80-psi oil pump in a street engine include excessive parasitic loss, bearing wash, and premature distributor and/or cam gear wear. “We’ve never seen a noticeable performance loss from the added load,” says Butler. “Racers will sometimes run a 60-psi pump to reduce parasitic drag and free up a few horsepower. While that’s acceptable in a dedicated race engine that’s frequently torn down, it’s certainly not something we recommend for all engines.”
He continues: “We’ve run as much as 100-psi on some engines and have never experienced any bearing wash issues. Excessive distributor or cam gear wear can result, particularly with a bronze gear, but we consider positive cam-gear oiling a must when running a roller camshaft, and we found that it significantly improves distributor gear life.”

One area that many hobbyists overlook when selecting an oil pump for a particular engine is camshaft type. “Some of the aggressive hydraulic- roller-lobe profiles available today and the high-pressure valvesprings required to effectively maintain valvetrain stability can cause the roller lifter’s hydraulic internals to bleed down too quickly, and that can create a performance loss. In these instances, additional pressure (75 psi or more) is required to keep the hydraulic lifters working properly,” states Butler.

http://www.hotrod.com/how-to/engine/...-observations/


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