If I posted close-up pics of the bronze gear used when we did 25-30 dyno pulls on my 440, could people check 'em out for signs of excessive or abnormal wear? It's my first experience using this type of gear and I'm not exactly sure what to look for to indicate wear issues with the limited run time. Thanks - Brad

After a few dyno pulls the gear should just be shiny. If you have any galling or wear then I'd think you are headed for trouble. I've seen both after the initial dyno test. Usually the bronze gears are just shiny but sometimes they show actual wear marks.

I need to take some good pics and post 'em. I don't know what's "normal" and what's " " at this point.

Probably not your case id hope but extreme wear in a short time of hard running in my case showed a cracked block.

A good idea is to make note of the slack (movement) between the drive gear and the cam when new. Then it's easy to detect wear if the thing is getting sloppy, by popping the distributor and checking with a large screwdriver or tool.

Or visually compare used to a new one.

How much end play did you put in??.. does it have a cam button ?

Sure!

Well, we can try.

Post away.

It's either an MP or a Milodon gear & shaft assembly; I bought one of each and don't recall at the moment which one I installed. I also bought a 440 Source bronze gear & shaft, but something about the teeth on that gear looked "different" than the other two, so it's still sitting unused in parts box.

Cam button = Yes; it's one of AndyF's rollerized buttons along w/ his timing cover

End play = .008", IIRC (tried a few different cover gaskets to get it w/in recommended range)

Also have a collar on the distributor shaft to keep the gear assembly from lifting up (.015" free play, IIRC)

Might get a chance to get pics tonight; otherwise, maybe late tomorrow.

Thanks - Brad

you'll notice a groove starting to cut the bronze where it meshes with the cam gear, if you can fell it it's starting to wear out. I've seen them last a few years and then again wear out in two weeks.

Didn't notice anything I'd call a groove, but the shiny pattern on the bronze where the gear & cam teeth mesh was definitely not the full width of the teeth. I was looking down into the lifter valley w/ a light, but will pull out the oil pump drive for pics.

I always compare the gear wear to the inside most area of the teeth. I noticed some weird gear wear on my small block on this last inspection and when I put it in the block to check how much slop it had it turns out the bushing in the block was shot. It hadn't been in very long but it was very worn so I changed it and put another gear I had in. I have always just dropped the gear in and never checked that bushing, I am glad I noticed it before it chewed up another gear.

Brad your oil filter will tell you a lot about what is happening to that brass gear.

bushings can be a big issue. I've got a bunch of new ones that are too loose to use.

Silly question: Why are you using a bronze gear in a street car instead of the melonized gear?

Here's something worth noting:

steel or cast iron crank ... babbit bearings
iron cylinder walls ... aluminum pistons
iron cam ... steel gear
steel intermediate shaft ... bronze bushing

All are dissimilar metals in contact with each other.

Now then ... steel cam ... bronze gear Here's the problem: bronze gear and bronze bushing

The majority of wear will occur on the bottom of the gear. The solution is a thin steel (.030") washer between the gear and the bushing.

Wear from tooth contact should be virtually nil. In the event there is noticeable wear from the cam teeth you have a MAJOR problem for which the only solution is dressing the teeth on the cam. Good luck with that !!!

I had a camshaft that would mow right through the gears I actually ended up taking some sandpaper and rounding the edges of the gear on the cam.. man night and day difference

In no particular order...

I have an oil filter cutting tool, but need to locate it after things got stuffed "wherever" when we had to deal with a basement plumbing leak last year.

I feel no detectable looseness between the bronze gear and the cam gear. I do think that I can push the oil pump drive shaft forward & backward maybe. 015" +/- due to bushing wear.

Dwayne Porter and I spoke about the melonized gear option a couple years ago when I was collecting parts. I run a high-volume oil pump, and the open spring loads with the new roller cam are about 600#s. If something about my combination does result in excessive wear on the treated steel gear, that's going to put more dangerous sh!t in my engine than the softer bronze gear, so I took his advice and decided to play it safe at this time.

We also talked about the possibility of sharp edges on the cam gear causing wear, which is why I used a small wire brush with a Dremel on the cam gear before installation. Not sure if it would have been better to use a small grinding stone and bevel the edges of the teeth, though.

I took a number of pictures tonight. However, the image sizes may be too large to upload directly from my phone. If they're too big, I'll have to shrink 'em some on my laptop and attach them tomorrow.

First image load attempt from my phone...

View of gear & cam before removing oil pump drive.

Contact pattern on bronze gear visible...