Long story. But found out my problem was from a very worn distributor gear. I have a Holley Sniper Hyperspark distributor. The supposedly Melonized gear stripped out after 1100 miles on a fresh professional rebuild. I’ve verified the pump shaft turns so I’m not sure what happened but could have been just poor quality Chinese part. Anyhow. Now I have a decision to make. I talked to the professions builder and he said I could put a new gear on and go but that I should drop the pan and clean it out and see how much junk is in there. When timing chains break do people always rebuild or do they clean out the pump screen and replace the pump and close it all back up? Would this be same thing? Replace gear, replace pump, clean out the junk in pan and get back on road?

the Cam gear looks to be in good shape. I spun engine with starter around and it’s uniformly shaped and no chunks. It’s a Flat tappet cam. Specs on the photo attached.

To replace the pump and clean out the pan I know I need to lift engine, drop pan, replace the oil pump and screen etc. I have a Crawler and engine lift crane. I also have plenty of Jack stands.

what would you all do? Other than replacing pump and verifying oil squirting from the pinhole what else could have caused this? There’s no adjustments listed as needed for a Hyperspark or olds distributor in the institutions. They are usually just plug and play

 

https://bopengineering.com/olds_v8.shtml

 

what is it made of? Adamantium? Verbranium?

 

it's carbon, and worth every penny. I went through a lot of bronze gears before Chad turned me on to it.

That's after probably 15,000 street miles and 25 or so passes with Brad Penn 10w40

 

Carbon what ?

 

Here’s a crazy idea…use, the , stock, GM, gear😳

even if it’s used…it’s an iron flat tappet cam right?

 

First of all I would have to take a serious look at what may have caused the problem. The cam gear does look ok so it might just be a bad distributor gear but I would want to be sure. It might be the picture but it looks as though the block is worn badly like the gear has been forced down against it. Ill have to take a look at the one I am building in the morning.

I have been using melonized gears from Chris Straub. I have done 2 Olds engine now with them and no problems. One was a flat tappet 425 and the other a Crane hydraulic roller in my Wifes 307.


Over the years I have become very cautious of using used gears on a new camshaft. I avoid it now days.

https://straubtechnologies.com/categ...tor-gears-olds

 

Also, Make sure that your builder used the correct plug with the oil squirt hole in the block. Here is a video I took a couple of years ago of a 425 I was preoiling.

 

I dig the idea of the Polymer one. I don’t have access to a old school old stock one that I’m not 100% sure issnt Chinesium metal

my guess is that the wear and torque and maybe defect in quality of the gear the outter layer of the Melonization wore out and then the cam gear just ate the rest slowly.

I spoke the the rebuilder who did it and he’s not heard of that many olds gears getting chewed.

I checked out the bottom of the gear and it’s clean and not worn. Would it not show signs of rubbing? Could I put some type of wax on the end of the gear when I install it and see if it depresses it when I lick it down? Then pull it out and see if it’s deformed?

 

Straubs gears are all made here in the USA

Did you try spinning the pump to make sure the oil hole is in the plug as in my video ?

 

FYI: "Melonizing" is merely a "propriety" case hardening of the surface about .003-.005" thick. Nitriding, Carbo-nitriding, cyaniding and a few other names are basically case hardening the outer surface of a low carbon steel (1020, 1030, 4130, 4330, 5130, 8630, etc.) to provide a hard wear surface. Without oil. they would all wear through the hard outer surface and keep wearing down.
Check to see if you have oil spurting when you prime the engine, as BillK suggested.

 

My first thought as well, check if the hole ist there and/or not cloged. If not then he might forgot the front one for the timing chain as well.

 

I’m not saying his gears aren’t ok. But your examples aren’t a very good testimonial. The first being a flat tappet, which is an iron core. And the second being a Crane IG core. All Crane/Olds roller cores where this way, an iron gear pressed onto them.
Just an fyi.

 

They are Morel gears and I have used them on plenty of other engines. Those were the two Olds examples. OP said his cam was flat tappet so almost any "good" gear should work for him. Thats also why I suggested he make sure there isnt something else causing it.

My feelings are still iffy on the polymer gears, especially on a street engine where you dont want to get stuck 200 miles from home. They have to drive the oil pump which can take quite a bit of torque. The distributor is just sort of along for the ride.

 

I've lived the nightmare, and the BOP "carbon/polymer" has been sweet dreams since the switch.
Sometime around the covids erra "supply chain shortage", the bronze gears i used to get from various sources went to crap. They went from 3000 mile wear items to only lasting a few hundred. My theory is that the offshore plant got confused between brass and bronze, whether it was intentional cost cutting or general ignorance, it happened.
I do agree that a standard, factory gear should be fine on a flat core.

 

Could a "tight" high volume oil pump perhaps combined with a heavy engine oil contributed to this?

 

"Chinese metallurgy" is.......different than USA (SAE) standards. Alloy and material consistency is a problem with "offshore" stuff, unless the "importer" tests the parts and material specification.
I am interested in these "carbon/polymer" gears and there longevity. Keep us posted.

 

i was running VR1 10w30 for a while then i used lucas 20w50 because of the high temps in CA and high temps at idle. i have a HP pump and improved oiling

 

I don’t know how I’ve got away for so long with using old factory gears on new flat tappet cams….and never had one fail?

 

Because the factory gear has the correct pitch diameter. The. Ones from MSD/Holley do not. The picture below stock on the left MSD on the right.

 

The cam is a stock type cam flat tappet cam from SpeedPro part number CD-1023R

The cam was NEW and not broken in at all when the NEW Hyperspark Distributor was intalled along with the new engine. The gear that came on the Hyperspark is a Melonized gear.

No shims were used. I dont even know how to shim an Olds distributor and there is nothing about shimming them in any olds instructions I have seen or in the Hyperspark or Cam spec directions. So that was not the problem I know that.

I have not had time to check the oil pump to see if i get a spray from the hole BUT I know that the plug is there. The Oldsmobile guy who built it builds Olds all day long for boaters and racers. Also there was oil ALL over the gear when I removed it so I think its getting oil up there. I had just finished cranking the engine over several times without starting it to see if my rotor turned.

 

whoooa.. Is this for real? Could the Cam have eaten away at the Melonized hardened portion of gear slowly and then once it had worn thru it just ate the non hardened much faster and that is why it failed so fast?

So I DO NOT want another MSD/Holley gear right?

Should Just bite the bulllet and get the Polymer one? will it have the right width and pitch?

 

I hope Mark (cutlassefi) chimes in on this. I asked him about the Holley distributor a few days ago and he said he has used plenty of them with no issues.

 

I had this problem on three cams. 1 taking the motor. No one I knew could figure it out. I checked the last gear about a half hour after cam break in. A new MSD gear was used. It was showing ware. I put a stock 69 350 distributor gear on after opening up to 500. I ran that one for a few hours with very little ware. At that time I pulled the engine and freshened it and installed a roller cam and used a bronze gear. The first bronze gear laster more than one season before I felt it needed to be changed. The current bronze great hos over 2 seasons with very little signs of ware. I measured the MSD gear using the 3 pin method and found it to be larger by about .008 compared to stock. The larger diameter caused the gear tooth to be wider. Since it's wider the cam cuts into it. I'm not believing the memorizing of the MSD gear is good. A file easily cuts them. That's my experience.

 

He has been emailing with me already. We were trying to figure out the problem and the order of operations was first try pulling the white wire on the ignition box and that tested out and the last thing was checking the timing and then pulling the distributor. The behavior of the problem was the timing and it was either the ignition box, the sniper itself OR the distributor.

 

So that is now two confirmations the MSD/Holley gears are a bad design or flawed. The wearing thru the outter hardened surface till the point the gear GOES faster seems to be what I experienced. I was fine and no issues for two years and then suddenly it went byebye

 

Not sure what that has to do with the gear wearing ??

 

it broke down. I didnt know why. There was backfires and unusual spark pattern. It seemed like the hyperspark was misfiring and my ignition box was bad. It was not until that I verified that was functioning that I yanked the distributor out. Its actually easier to do it that way because yanking the distributor messes up the timing sync and phasing. thats when I discovered the rotor was turning just not in sync with the crank.

 

I’ve never had problems with Holley/MSD gears/distributors either. I’ve got more than a few out there on street cars with lots of miles on them. This one has the Holley dizzy in 6 years ago. The gear on the right in your pic should not have a worn upper surface like that..the top of the gear is not suppose to contact anything. Visually, it also looks like the root depth is smaller,, thats because it has a much larger chamfer on the gear. That doesn’t have anything to do with its pitch diameter.

I’ve never had any reason to measure the pitch diameter because I’ve never had problems. I will measure the next new one to see what it is though.

 

I am going to do some more investigating this week. I have just started a 350 stroker build and all I have in the block is the crank and the Comp hydraulic roller cam. My customer has a new Holley dual sync distributor and I have at least 2 stock gm distributors at the shop. It will be real easy to put some gear marking compound on the distributor gears, stick them in the block and spin the cam over a few times.

I will post results for what its worth. Might be a few days because I am overwhelmed with work right now

 

Thanks BillK.

 

How do I know what size gear to get? .491 or 500?

 

Measure your distributor shaft. GM HEI is 0.491 and MSD is 0.500

 

wow that’s a nice stream. I need to check that next time. I use the BOP gear mentioned as well on a 403, 2500 miles so far so good.

 

I was surprised at how much oil came through there to be honest with you. I think that was the first time I had done an Olds on the stand like that

 

I primed one once and forgot I didn’t have the timing cover on the front plug will shoot a stream about 50ft

 

That must have taken a whole bag of Kitty Litter to clean up

 

Question for those that have the bronze gear that you check and replace. What do you do when it finally gets worn out? Do you pull the engine and rebuild? Or do you just replace it and go? Do you drop the pan and replace it the oil filter and oil pump?

I am not ruling out that there is something else going on, but i figure $180 for a new composite gear and dropping my pan and replacing the pump might get me many more miles out of a car that hardly drive. Will it hurt anything If I do it that way? Bidenomics has been really hard on me. my housing is doubled. my insurance is doubled, but health insurance is up by a factor of 8X what I used to pay, my commuter car is a Diesel and that USED To be cheaper than gas, but not anymore, and my property taxes are going up now too. OH, and electrical has doubled too. I would rather try for the $180 option than the $3000 one. OH, I am also supposed to eat something in there and have groceries money. It is just me though. No woman or kids thankfully!

 

When the brass (Chinese "bronze") gear really gave up the ghost, it left me on the side of the highway and I got towed. Prior to that, I would check it periodically/during oil changes. Yes, throw a new one on and go. That being said, I was never a fan of wondering where the worn off material went.

 

Ok, so then dropping the pan, clearing the junk, replacing the pump, and flushing as much as I can with a few oil changes should in theory get my back on the road at least until it blows up again. THEN I can do a rebuild.