Technical Bronze Distributor Gear

Is that gear still in production?

 

Lunati Distributor Gear Everwear or composite

 

Back when.....Used the bronze gear on the roller.....It was the sacrificial item........The one pictured in the first post is toast.......Street driven should last a long time. 50 p***es at the track=it was checked, but serviced after a season as regular maintenance.......As usual, results may vary.

 

If you do a search & have used , there has been problems /concerns unusual wear with Bronze gear's since 2007 to present

 

Bronze distributor gear cost my buddy a 509 due to the particles floating around in the oil.

 

I wonder if that corresponds to the lesser Zinc used in oil? I’m not sure it’s even relevant, just wondering.

 

I honestly would have never guessed we would discuss this for a couple pages. Seems there are some varied views on bronze gears as well as varied results. I was convinced that I wanted a composite gear until I went and found that everyone seems to be out of stock on those now. I guess I will either wait or likely order a melanized gear for a replacement.

 

Doesn't look good...
pp1110a.indd (cranecams.com.au) no listing from downunder
NEW WEBSITE FOR CRANE CAMS | Compe***ion Plus nothing to see here.....

Like many things in my life, I should have bought a couple dozen when I had the chance.

 

I'd go with the composite. You have already seen what the bronze gear does, and it will happen again....maybe with the loss of the engine. Here is an article you might want to read.
www.enginebuildermag.com/2009/07/properly-matching-your-camshaft-and-distributor-gear/

 

Maybe everyone is switching because they know they work............

 

You may be on to something there.

 

Crane I think had cores that the cam gear was pressed on and did not require bronze.

 

It seem to be the bronze gear made around early 2000's to present , Old bronze hold up before 2000's. I wonder my self if it was Zinc related , But I have seen Later bronze eating up with Vr1 oil & other Race zinc oils,,,
One thing about composite gear , when Cold climate temps Oil below 50 ish Deg"s , make sure to bring Oil temps up be for putting a load on gear , they will break /strip . I have used on street when 30'deg's Only after oil temp up above 100 degs with No issues..
Also when it comes to roller cam manufacturers talking to Tech Suport most the time to me it sounds like you're getting an answer that they are not even sure of what is the correct Gear to run on their camshaft this includes most well-known name brands besides just Com Cam's
((( Not sure of ther core are coming from over seas)

 

my son has one from hwards cams with the pressed on gear and rear bearing journal has been trouble free for 7 or 8 years with a standard distributor gear even has a high volume high pressure oil pump

 

Definitely understand the tech support comments. The connection I have at Comp came through a friend and that person has been at Comp a long time (at least sometime before 2000) which is why I trust him. He has helped me out with a blown BBC hydraulic roller application in the past few years so I have got to know him better. This guy is also an application guy and not tech support too.

 

I have personally not lost a bronze gear , but I do stay away from using the 2000 plus bronze,, I also wonder if failure has anything to do with Cam Walk & gear to cam meshingv just like setting up a rear end gear & pinion??

 

Now you guys have got me worried. When I had the '54 New Yorker hemi in my dirt modified built in the mid-nineties, the builder installed an NOS Engle roller tappet cam that I had found. My engine builder said he changed out the "drag racing" springs and subs***uted something more friendly for the vintage racing I was doing. He also said that he looked high and low and finally found a bronze gear for the distributor. I ran that setup for years with no problems.

When I originally had the engine built, it was ran a Cirello "Frankenstein" magneto. Several years ago, it became hard to start, Tom Cirello is still running the company, and when I talked to him, him said that the magnets were probably weak and the whole unit needed to be rebuilt at what I considered to be a fair, but exorbitant, cost. I ended up selling him the magneto at several time which I paid for it, because I had a good "Flattop" Mallory for just such an occasion. This combination has performed admirably also.

The hemi has no distributor drive gear because, as I understand it, there is an intermediate gear that runs the shaft. I should still have that gear in the engine, so the distributor change should have had no effect. However, that intermediate gear is now going on 30 years old, and now I am starting to wonder if I have problem waiting to happen. I have spent a little time looking and it seems they are now nowhere to be found. My inner self tells me not to worry about it, but this thread has brought up some new doubts.

 

Its not hard to tell if the dist gear is wearing.
Telltale sign is, if you are losing initial timing from where it was set initially and there is a lot of backlash on the dist shaft, the gear is wearing.

Bill

 

I have seen gear go with in a few hundred street miles , probably equals to 250 1/8 p***es ,( A season )
Best thing to do pull distributor maybe every 20 or 30 miles a few times just to check the wear on the gear, It ****s but do you take the chance??

 

That sounds like a good idea, but what do I do if there is a problem? Everything I can find says these are now made of "unobtainium". Does anyone have a source?

 

I cant seem to find anyone that has 12140 composite gear for an MSD .500 shaft diameter in stock either.
Wonder why??????????

Bill

 

Summit has melanized ones for a .500 shaft in stock.

 

I am pretty much full GM , worked on many other brands Think and experiment outside of the box ,,I've done a lot of reading ,,,,,So pulling this off the top of my head /memory ,,,when GM switched over to roller cams 95 to 2000 you can take the gear off one of those distributors (OEM gear) bore the .009 and slide it onto your .500 , the GM gear will work hold up ,,, I ve research, I did and reading was not a 20 minute search it's many many hours because some people just repeat the same thing ,but then you find ones that know/ tried ,using ...
Research engine builders outside of drag racing ,,, power boats ,dirt track NASCAR , EXT

 

From what I understand, a Melonized dist gear on a older manufactured billet cam core is a reciepie for disaster.

The cam makers have changed their manufacturing process for steel billet cams in more modern times, and some can use a Melonized dist gear, some can not.

Every listing I have seen for a 12-000-9 style camshaft says, requires a bronze dist gear.

Guthriesmith has the cam card from Comp Cams. They should be able to tell him when it was made and what was recommended for a dist gear at the time it was produced, but he needs to talk to someone thats knowledgeable at Comp Cams and not get an answer like I think a Melonized gear "SHOULD" work.

If the composite gear is not available, then his only real option is to go back with a new bronze gear until the composite gear is available, if ever.

My experience with a billet cam core and a bronze dist gear was about 200 street miles, and a 1/2 dozen drag strip p***es before I noticed wear and replaced with composite.
The composite gear has been in there ever since.


Bill

 

The option to all of the questionable gear combinations is to graft the back of cast stick onto the roller and then use an earlier oem gear....at least that is my solution for an EarlyHemi since there is no shortage of LA cast cams and gears.
This process should work for other engines.

 

i feel your gear wear pain. i run a fed blown 350 buick that i replace the dizzy and cam gear every year. if this was a stock engine 250k miles would not show wear. but what i do does. i have had new gears treated and polished, didn't help. went to a bronze dizzy and the gear wear slowed down, but still become paper weights. they do make a melonized dizzy gear for $180, ouch. may have to buy it.
another issue i found was buick's aluminum timing cover is not built to go racing at +6500. the dizzy hole stretched from it. but searching for a possible answer, i found OMC boats in the 60' used the buick v6. aluminum t/c's were fresh water, but salt water they used cast iron t/c's. yeah! this change helped in lowering my gear wear, but still there. but the cast iron will not stretch. other option is to go distributorless. but thats way too much technology. trying keep circa 1968.

 

Hey Bill,

When I sent a pic of the cam card to my connection at Comp, he said I could use and even recommended a melanized gear. I’m not positive of the date it was built, but would guess it was built in 2016 or so going off the SN on the card and also knowing when my buddy built the motor. My buddy that built the motor had just finished it and got the car running right before he died and that was in 2017.

Jeff

 

What would concern me is the fact that you'r buddy replaced the gear on the MSD dist out of the box, which would have had Pt# 8531 already installed. (Melonite QPC coating as MSD calls it)
He replace it with a high wear item (bronze gear).
I doubt he did that just for the hell of it.
Leads me to believe he was told by Comp Cams or someone else it had to have a bronze gear????

I pulled my Comp Cam solid roller cam card, which is from around 2004, and there is no reference as to what type of gear needed, but know for a fact (told by Comp Cams back then) it had to be bronze or composite, not melonized or bare iron.

Maybe you'r cam can use a Melonized gear as you'r guy at Comp Cams recommended, but will he guarantee it will not fail the engine if it does, if he was wrong??????????

Also dont know what the difference is but MSD lists two dist gears for chevy .500 shaft
#8531 Melonite QPC coating
#8561 Melonized, marine (some places say for use with solid roller cams???)
Dont know what the difference is, I think Melonite coating and Melonized means the same?
Dont know it pitch is different or not (not a marine guy)

If you decide go with the Melonized, I would probably use the one from Comp Cams, but I am worried its the wrong choice.

If it were me, I would try to find out why/when the composite gear will be back in stock and go back to bronze and monitor it often. Id be too worried that you'r buddy put that bronze gear on for good reason.

Bill

 

All valid points for sure. I wish I could ask my buddy why he put the bronze gear on but can’t. As an aside, he was one of the Street Outlaw guys that ended up having a m***ive heart attack and died in his mid 40’s one night. Sad deal for sure and you couldn’t have met a nicer or more humble guy despite the reputation that Street Outlaw guys might have in general. Anyway, my other buddy that owned the car at the time wouldn’t know either.

So…in all this discussion, and the fact that I still haven’t ordered anything to fix this deal, I may just keep checking on the composite gears. Whatever the case, feels like I should report back if nothing else to help with this overall debate of bronze vs melanized vs composite and the pros and cons of each depending on application.