distributor gears and cam cores

[BBO Omega]

The gears MSD uses on their Pro Billet Distributors is Melonized. They also sell them separately.

[CamKing]

The problem is, Comp Cams, like the rest of us in the cam business, but cam cores from multiple cam core suppliers(EPC, CMC, Callies,...)
Those companies uses different steels for their billet steel cam cores. Some will work well with a Melonized gear, others, not so well.
If you but a steel billet cam from Comp, you need to know what steel it's made of.
Here's a partial list of some of the steels used by the cam core manufacturers: 1050, 1055, 1060, 4150, 5150, 5160, 8620, 8660, 9310.
Besides the different materials, there's different heat treat processes. Some are induction hardened, Some are Quench and Tempered, and some are Carborized. an Induction hardened 1055 cam core will work great with a Melonized gear. A Carborized 9310 cam core, will not.

[Flo]

Hi Mike,

thanks for the insight.
For the cams I bought from you, I will ask you what to you use when time comes for installation Still had no chance to get to my own 400/512 I ordered the last cam for...

However, what does this leave me with regarding the Comp Cams? Try stock gear and check for steel chips at oil change?

Greets
flo

[CamKing]

Hi Mike,

thanks for the insight.
For the cams I bought from you, I will ask you what to you use when time comes for installation Still had no chance to get to my own 400/512 I ordered the last cam for...

However, what does this leave me with regarding the Comp Cams? Try stock gear and check for steel chips at oil change?

Greets
flo

Run a melonized gear, and just check it and the gear on the cam, a few times for wear.

[Walter R. Malik]

The gears MSD uses on their Pro Billet Distributors is Melonized. They also sell them separately.

That would seem great but, Mopar distributors have no gear.

The gear is attached to the oil pump drive.

[Schurkey]

That would seem great but, Mopar distributors have no gear.

The gear is attached to the oil pump drive.

Isn't there a bronze bushing in the block that supports the oil pump drive? Doesn't it tend to wear oblong, which would screw up the gear mesh?

Has it really been 20 years since I've pulled a B--RB distributor out?

[Flo]

I always make sure the block bushings are replaced / in really good shape.

As Walter pointed out, limited option for what is technically the oil pump drive gear on Mopar:

stock, bronze or steel from Crane

Mike, which of the above should I use with one of your hydraulic roller cams?

[CamKing]

I always make sure the block bushings are replaced / in really good shape.

As Walter pointed out, limited option for what is technically the oil pump drive gear on Mopar:

stock, bronze or steel from Crane

Mike, which of the above should I use with one of your hydraulic roller cams?

The Crane Melonized gear

[Flo]

thanks for the clarification

[mag442]

I have 3 RB440 engines that I have in service at the moment. All 3 are roller cam and have bronze distributor gears. All 3 have very high gear wear. Doesn't seem to matter if they are standard volume or high volume oil pumps. We have tried numerous things to fix this. Even modified the oil system to spray oil directly on the gear. This made no difference at all. On Mike Jones recommendation I installed a Crane coated gear to the engine that gets the most use. I have checked the gear and cam numerous times since and have no wear......looks like a winner to me in a crappy situation.

[jsgarage]

Something that doesn't seem to get much discussion are 'street roller cams' that are steel with a cast iron front journal & cam gear. The assembly is apparently indexed and pressed together, maybe with a woodruff guide key. Then you use a stock iron dizzy gear. I doubt if two-piece cams are strong enough to withstand the huge valve springs some racers think they need & 9500 rpms are likely not recommended, but for normal street/strip, it sure seems better than '1000-mile-bronze' gears that dump all that metal in the pan. We in the Cleveland family have been fighting this situation for decades as there never were factory steel roller cams & dizzy gears for that engine.

[Walter R. Malik]

I always make sure the block bushings are replaced / in really good shape.

As Walter pointed out, limited option for what is technically the oil pump drive gear on Mopar:

stock, bronze or steel from Crane

Mike, which of the above should I use with one of your hydraulic roller cams?

The Crane Melonized gear

Good to know, Mike.
Crane doesn't call their special gears "Melonized" which I think is the issue with making them known
221-69970-1 is the Crane part number for the Mopar gear. I just ordered one from Jeg's so I have it when I need it.

[Walter R. Malik]

Something that doesn't seem to get much discussion are 'street roller cams' that are steel with a cast iron front journal & cam gear. The assembly is apparently indexed and pressed together, maybe with a woodruff guide key. Then you use a stock iron dizzy gear. I doubt if two-piece cams are strong enough to withstand the huge valve springs some racers think they need & 9500 rpms are likely not recommended, but for normal street/strip, it sure seems better than '1000-mile-bronze' gears that dump all that metal in the pan. We in the Cleveland family have been fighting this situation for decades as there never were factory steel roller cams & dizzy gears for that engine.

There are composite distributor gears for that engine and the big block Ford available from "Tritec Motorsports".

[MadBill]

... I doubt if two-piece cams are strong enough to withstand the huge valve springs some racers think they need & 9500 rpms are likely not recommended, but for normal street/strip, it sure seems better than '1000-mile-bronze' gears that dump all that metal in the pan...

Perhaps camking will weigh in, but he put no restrictions on the 'cast gear' steel solid roller he did for my BBC. 0.720" lift, 250# seat load.
Manual transmissions often have press fit gears transmitting several time engine torque. Roughly speaking, the shear force a pressed joint will resist is about the same as the installation press force, e.g. a 1000# press fit onto a 1" shaft will transmit a max of ~1000 x 0.5" = 500 lb-ft.

[Krooser]

Hughes Engines offers a melonized gear for the BBM.