[BARRACUDA1968]

I pulled the dist yesterday just for an inspection and noticed the poly gear has some wear. I'm running the comp XR288HR so I was told to run this gear. This is a 1000 miles.

Can I still run this gear or should I replace it? Just not sure if this might be normal break in characteristics of a poly gear?

I have read I should have used brass for break in then switched to the poly. I don't want to spend another $125 and have this same issue.





Thanks Brett

[cgeise]

get it out of there - I had one fail and it was at the worst time -- I think breaking it in with bronze then switching to the composite gear is a good idea -

[BARRACUDA1968]

I guess I'll go bronze for a while and see what happens unless anyone else has a different opinion?

Thanks for the information cgeise!

[grandville455]

Agree with Curt! Run the Bronze, That's chewed up too much

[ta man]

Ya its chewed..I took fellow board members advise and ran a bronze gear for a Cpl hundred miles,then switched to a BOP..

[BARRACUDA1968]

Ok so now I go to the bronze gear then what? Run that for how long? or maybe permanent?

I asked the business where I got my parts and a lot of advice which I won't name what might have caused this. I sent pictures.

Here's the response;

"We have not seen the issue before. 99% of the people use polymer gears because the bronze wear quicker.

You may install the plug in the rear pass. Oil galley to oil the dist and cam gear.

You can check the cam gear for a nick or bur."

Opinions?

[grandville455]

My engine guy drills a small hole in the plug to help oil the gears back there.

[BARRACUDA1968]

I'm brand new to the Pontiac High Performance so I know we didn't do this during assembly.

What is my best option now to help my dist gears live?

[GTO Dan]

I've had that happen. You need to clean-up any rough edges on the cam gear before installation. Nothing too aggressive, you just want to polishing it a bit.

As mentioned, an .030 hole drilled into the oil galley plug to feed the gear is a common mod for street driving and longevity but I don't think it would have helped in this situation.

[charlie66]

Did you have good endplay with the gear on the distributor it self? I always tighten it up from what it comes with...

[cgeise]

I used the plastic gear for quite a while on a cam that had been run with bronze previously and had no problems for a few years - only when I started swapping new cams in that had not been run before did I eat the gear up - it would seem that the bronze polishes the cam up so the plastic can live. Thick oil also puts a lot of strain on them. and the drilled galley plug is never a bad idea.

[AG]

I polished the gear on my billet SR cam with a wire wheel and cloth with brown rouge and used a BOP polymer gear and have had no wear on the dist gear.

[Jack Gifford]

Originally Posted by BARRACUDA1968

... Ok so now I go to the bronze gear then what?...

A bronze (or brass) gear does tend to wear. But the nice thing is that it won't suddenly fail (like polymer can)- as long as you check it now and then for faster-than-usual wear. So... run it until you tire of seeing the "sparkle" in the oil!

[1969GTO]

isn't there a concern with the brass flaking ?

[BARRACUDA1968]

Originally Posted by charlie66

Did you have good endplay with the gear on the distributor it self? I always tighten it up from what it comes with...

Did not check this, it seems to have some movement. What do you recommend?

At this point I don't really want to pull the motor to clean up the cam and do any mods.

I'm taking it that running the bronze gear will clean up the cam gear safely so I can go back to poly down the road?

[grandville455]

I think U would like around .020 endplay with HEI if I remember right? I would just run the Bronze for awhile longer to clean up that cam gear more than pull Bronze gear inspect, and if it looks good then switch back to a poly.

[BARRACUDA1968]

Thanks Darby

I got your text and I'm working on getting everything needed to modify the carb today.

[charlie66]

Originally Posted by BARRACUDA1968

Did not check this, it seems to have some movement. What do you recommend?

At this point I don't really want to pull the motor to clean up the cam and do any mods.

I'm taking it that running the bronze gear will clean up the cam gear safely so I can go back to poly down the road?

I run it real tight. Somewhere around .007 to .010. I have even run it tighter. I've never had a problem with a Composite gear... even with it at .005.

Do you use anything like a Super Lube Break-In Concentrate with your oil . I always do. Not saying that's why you have this problem. Just sharing what I do.....

[BARRACUDA1968]

I did not use any type of break in oil etc because of it being a roller set up. We used normal assembly lube and primed the motor etc.

I also run ZZDP Zinc because I run magnum rollers rockers which are not a full roller rocker just roller tip.

[charlie66]

The ZZDP is good to use..