Brass distributer gear failure !!!

[Cobra Fog]

What to do? The brass gear on my MSD distributer is missing a couple teeth and the rest of the teeth look badly worn. I only have 3700 mile on my 347 stroker motor. Do I need to tear down and rebuild or can I get away with dropping the pan and changing filter and Oil pump? The car just died on my way to a cruise in and in troubleshooting I discoverd the gear failure. What a bummer. Has anyone else had this happen and what did you do? Thanks for any input.

Dale

[Gordon Levy]

I'm actually quite surprised the bronze gear lasted that long. It really isn't meant for street used.
I would consider dropping the pan, you would have a chance to clean it out and check things over.

[RobbieD]

Originally Posted by Gordon Levy

I'm actually quite surprised the bronze gear lasted that long. It really isn't meant for street used.
I would consider dropping the pan, you would have a chance to clean it out and check things over.

Sorry to hijack, what would a brass/bronze gear be used for?

[mutineer]

Originally Posted by RobbieD

Sorry to hijack, what would a brass/bronze gear be used for?

I think that they are used for racing only, if my understanding is correct

[Big Blocker]

Here we go again . . .

Some people use them on their steel cams because they are under the impression that as long as they DON'T use Iron on a Steel cam, they'll be OK . . . Maybe yes, maybe no.

There have been numerous threads about the dreaded "cam to dizzy gear failures" on this site and many others. If you are going to run a steel cam, get a steel gear.

There is no mention of what was used in the OP's post about his Bronze gear, was it an Iron cam, Steel cam . . . . Hydraulic, solid lifter, roller???

Do a search for cam gear failure and start your journey to enlightenment.

Doc

[Cone Basher]

FOG: FYI if you want info on this try the following: go to google or use the link below and enter site:ffcars.com brass gear failure or distributor gear failure or distributor gear material and you should get lots of info. Great source if info. If this is not news to you please ignore.
HTH
CB

[Bill 21]

Originally Posted by Cone Basher

FOG: FYI if you want info on this try the following: go to google or use the link below and enter site:ffcars.com brass gear failure or distributor gear failure or distributor gear material and you should get lots of info. Great source if info. If this is not news to you please ignore.
HTH
CB

My experience has been, if you use a brass gear, you should use a high volume pump and not high pressure. High pressure makes the gear wear out quickly.

[JKleiner]

Originally Posted by Bill 21

High pressure makes the gear wear out quickly.

Although high pressure may accelerate the process the reality is that soft bronze on hard steel is what wears the gear.

Jeff

[trevor]

at the track I saw a steel gear eat a comp cam gear using a high volume oil pump. The cam was a hyd. roller and req'd a steel dist. gear. Its seems to be more complex than just the gear. No matter what, I wouldn't use a composite or brass gear to drive an oil pump. That just doesn't make any sense.

[J Persons]

Originally Posted by Bill 21

My experience has been, if you use a brass gear, you should use a high volume pump and not high pressure. High pressure makes the gear wear out quickly.

Concerning the oil pump, I have never seen a listing for a high pressure oil pump, only high volume pumps. If you use a high volume pump on an engine with stock internal clearances, you will see high pressures using a high volume pump.

[MikeKelly]

Lots of good info + links here:

Distributor Hold Down Issues!

HTH,

Mike

[charles roybal]

Stay away for MSD composit gear.

[MARIAH]

Sorry to hear that Dale. I listened to the machine shop guy when he put the Bronze on MARIAH's MSD distributor.

After about 1500 miles she seemed to loose power and timing. All the teeth were still there but they were down to knife edges ready to rip right off. She's been steel ever since. Of course I am stock and you are well...... more than stock.

Keep us posted.

[Lex]

On a racing engine we used to change the brass gear at every rebuild which was aprox every 4th road race or full weekend. Finally just went to steel. As far as steel eating a Comp Cam gear I've seen this happen several times and is why I wont touch a Comp Cam! There was a thread a while back dicussing this, where they found out that the Comp blanks wern't a steel core so the gear wasn't steel. All Comp's tech would say was that some of their cams were made that way (so how do you tell which ones?) so they recommend using a composite gear.

[Big Blocker]

High Volume creates high pressure . . . how? when the pump has a pressure relief valve built in that regulates the pressure output. Excess pressure is vented back to he pan.

I see this thread drifting into the old high pressure Vs. high volume discussion that has been talked to the point of nausea.

Back to the OP's question . . . use a steel gear on a steel roller cam = no issues.
Use anything else = numerous issues, up to and including engine failure.

Doc

Just my 2¢

[tirod]

One of the mistaken notions about oil pumps is that a high performance engine needs something extra to survive hard use.

The real reasons for the pump lie in bearing clearances. If you run them big, you have more loss of oil, and "they" install a race pump to compensate. "They" also tear them down repeatedly during a season.

If you haven't done anything extreme to the block and bearings, a high performance pump will only try to stuff more oil into the galleries and into the bearings. That means that if pressure goes too high, it gets dumped. Oil pumps use hp to work, dumping pressure means work wasted.

Like a lot of other parts, it's part of a system - modified galleries, radiused corners, race clearanced crank and rods, race bearings, etc. Just bolting on the pump means you likely don't get much from it, you lose hp churning the oil harder just to bypass it.

In the Windsor motor, WHAT DRIVES THE OIL PUMP? The distributor gear.

It's all part of a system . . .

[Cobra Fog]

I have learned a lot about distributor gears and cam gears and oil pumps over tha past 2 days. Thats why I like this forum so much. I have ordered my new distributor with a steel gear to match up with my cam set up. I did not know the engine builder set my motor up for the strip by putting in the bronze gear. So this has been a painful but valuable lesson. I will be changing oil and filter a couple of times and putting in a new distributor and keeping an eye on my oil pressure to be sure I don't have other issues develop. Hope to be back on the road soon. Thanks again to all of you that responded.

Dale

[Don Payne]

Originally Posted by Cobra Fog

What to do? The brass gear on my MSD distributer is missing a couple teeth and the rest of the teeth look badly worn. I only have 3700 mile on my 347 stroker motor. Do I need to tear down and rebuild or can I get away with dropping the pan and changing filter and Oil pump? The car just died on my way to a cruise in and in troubleshooting I discoverd the gear failure. What a bummer. Has anyone else had this happen and what did you do? Thanks for any input.

Dale

I guess I'll chime in here. The first I read the title of this thread I thought to myself "Well, this is an oxi-moronic thread, brass gears are designed to fail". Like brake pads, brass distributor gears are supposed to wear down.

Like Gordon mentioned, these are not for street use. They are intended to protect your more valuable components, like your camshaft, and are designed to disintegrate without destroying your bearings. If it were an iron or steel gear, it would require a full tear down like what I had to do. In your case you just need to replace the gear, and it would be good to clean out your pan.

I apologize is this reply sounds flippant, I don't mean it that way. Just relating my experience.

Cheers,

[Mr. Barry]

Well, been on the forum now for more than 10 years, and have read this same theme repeated maybe 500 times.....
First rule, don't use a high-volume pump on a street machine....
Second rule, never use bronze gears on a dizzy for a street machine.....
Two easy rules, frequently disregarded....
Finally, don't try to get away with just replacing the gear....Drop the pan, and clean things out.
Edward

[CobraSnake7]

Here is my 2 cents worth. I have a high volume pump on my 429 SCJ with 10,000 miles on the engine. The pressure runs around 70, and I have had no issues with it. I only drive it on the street.

[Gordon Levy]

There is a really big difference between a BB and a SB. The drive gear on the BB is twice the size of the one on the SN. That small gear size is one of the reasons for failures when using a HV pump.

[TAnderson]

Gordon,
How would you clean the debris from the motor?
Drain the oil, drop and clean the pan, replace the oil pump and filter.
Prime the oil pump while rotating the motor by hand.
Get one of the oil filter can-openers and check for metal “frag” in the new filter.
Repeat as needed until the filter is clean of debris?
Or is it better to just break it down, clean everything and rebuild?

[Gordon Levy]

I would drop and clean the pan. Pull and inspect the pump and most likely replace it. Put it together with a clean filter, pre-oil and run it.
Remember that the first place the oil goes from the pump is to the filter so actual depris in the rest of the engine should be minimal. If you use a remote filter, all the lines and adapters need to be cleaned.
If there was a lot if crap in the bottom of the pan I would consider checking a few of the bearings and proceeding forward based on what I saw.