distributor gears and cam cores

[Flo]

Hello all,

would you contribute some first hand experience on the topic of cam core materials vs. distrobutor gear materials?

Background: I have several customers/buddies over here, who actually REALLY drive their old iron... a lot I guess! Like several 1000mls a year. Which makes me run into problems, noone else seems to have.

Most recent: I have a guy with a Mopar big lock (400/470cui) with a Comp solid roller 23-741-9.
That cam was chosen, because it really seemed to have mild lobes and was listed as a "street roller" by Comp, so we hoped it would not be so hard on parts. That car gets driven around 2000-3000mls annually + some 1/8 miles passes.

After wearing out the second bronze oil pumpe drive / distributor gear within 18months, I contacted Comp techline on what to do


Their answer is pretty much:
- a -9 core is a billet steel core
- on a -9 core you can only run bronze gears, all others will eat the cam!
-bronze gears will last around 1000mls ish, that is their idea of street/ strip.
-if something is supposed to run that much on the street, a -9 cam is not recommended, they can spec something different (most likely custom).


Is this true???

Looking through the Comp catalog, pretty much all retro-fit hydraulic roller cams are also on -9 cores! Why would you run a hydraulic roller and exchange distributor gears every year?!?

What are you guys doing, how are you hadnling this?

Greets
Flo

[Schurkey]

Do they have cores available that use an iron distributor drive gear?

That sort of thing is common in the Chevy world, I don't know about Mopar.

[blykins]

Billet steel cams get steel gears.

I'd say 90% of my engines get -9 or -11 cores from Comp Cams. I run steel gears on them and have had 0 issues. With that being said, pretty much all of my engines are Fords, which have a gear installation dimension spec, but I have never had any luck whatsoever out of a bronze gear. Your results are basically what I would expect from a bronze gear.

Comp doesn't sell steel gears, so they are going to recommend bronze, and obviously, you can't run iron.

[Flo]

Thanks for the replies.

Hmmm, Crane sells a steel gear for big block Mopar:
https://www.summitracing.com/int/parts/ ... /overview/

@blykins:
that is what you use and it works for you? I would have liked Comp to at least mention that....

[blykins]

Yes sir. I run steel gears on my billet steel core camshafts and iron gears on my cast iron stuff. Never a problem.

Most of my gears come from Crane or MSD/Mallory.

[GOSFAST]

We've done a high number of retro-hyd-roller Pontiac builds using Comp's -9 blanks and all ran the factory OEM dist gears, not a single issue and some of these are out back in 2002!!

Thanks, Gary in N.Y.

P.S. On most all of our 100% stock-appearing Chevy's we stay with the -8 blanks and use the OEM dist gears and feul-pump pushrods. Again, some are out way over 20 years and not one single lobe/lifter failure!! The BBC streeter's are all in the neighborhood of 750+ HP. All OEM components, keeps it simple for our customers.

[Walter R. Malik]

First of all a -9 core only is a price measure, not what the core is made from. Comp Cams billets are made from different steels not just ONE, though that may be the only one offered for that engine.

Steel distributor gears will eat some billet steel cores. The Melonized distributor gears seem to work very well in those situations but, I don't think a Mopar gear is offered so. you need to use the bronze or composite.

I have had some luck making my own from regular cast gears by shot peening a production gear and then having it nitrided.

[Flo]

Darn, for a minute I thought, there was an easy answer

Bronze is really not an option for the applications here if they dont last.

I could not even find a composite for Mopar.

Only stock, bronze or steel from Crane!

So in the end I guss, I just have to try stock or steel and see if it eats the cam?!?

Thanks for all the input.

[blykins]

First of all a -9 core only is a price measure, not what the core is made from. Comp Cams billets are made from different steels not just ONE, though that may be the only one offered for that engine.

Steel distributor gears will eat some billet steel cores. The Melonized distributor gears seem to work very well in those situations but, I don't think a Mopar gear is offered so. you need to use the bronze or composite.

I have had some luck making my own from regular cast gears by shot peening a production gear and then having it nitrided.

Walter, I get both -9 and -11 cores from Comp and my rep told me that they were in fact different materials.

[Walter R. Malik]

First of all a -9 core only is a price measure, not what the core is made from. Comp Cams billets are made from different steels not just ONE, though that may be the only one offered for that engine.

Steel distributor gears will eat some billet steel cores. The Melonized distributor gears seem to work very well in those situations but, I don't think a Mopar gear is offered so. you need to use the bronze or composite.

I have had some luck making my own from regular cast gears by shot peening a production gear and then having it nitrided.

Walter, I get both -9 and -11 cores from Comp and my rep told me that they were in fact different materials.

I have several -9's from Comp Cams for many different engines which are different materials.
Matter of fact ... I was evaluating 2 big block Ford "custom" 000-9 camshafts this past Friday of different materials as well as the bolt threads in the front being course thread in one and fine thread in the other. Some -9's even have 3/8" threads in the snout instead of the 7/16" thread.

[tuffxf]

Gday,
Been led to believe there is a big difference in bronze gear quality, cstraub sells ampco 45 us made gears,
At about the time you may be changing the gear you will be checking the rollers anyway.
Cheers

[user-17438]

Hello all,

would you contribute some first hand experience on the topic of cam core materials vs. distrobutor gear materials?

Background: I have several customers/buddies over here, who actually REALLY drive their old iron... a lot I guess! Like several 1000mls a year. Which makes me run into problems, noone else seems to have.

Most recent: I have a guy with a Mopar big lock (400/470cui) with a Comp solid roller 23-741-9.
That cam was chosen, because it really seemed to have mild lobes and was listed as a "street roller" by Comp, so we hoped it would not be so hard on parts. That car gets driven around 2000-3000mls annually + some 1/8 miles passes.

After wearing out the second bronze oil pumpe drive / distributor gear within 18months, I contacted Comp techline on what to do


Their answer is pretty much:
- a -9 core is a billet steel core
- on a -9 core you can only run bronze gears, all others will eat the cam!
-bronze gears will last around 1000mls ish, that is their idea of street/ strip.
-if something is supposed to run that much on the street, a -9 cam is not recommended, they can spec something different (most likely custom).


Is this true???

Looking through the Comp catalog, pretty much all retro-fit hydraulic roller cams are also on -9 cores! Why would you run a hydraulic roller and exchange distributor gears every year?!?

What are you guys doing, how are you hadnling this?

Greets
Flo

I have a guy that puts over 3k miles a year on his.

496bbc crower needle bearing lifters 275/285@.050 109lsa . Stainless valves 330 seat about 900 over the nose.

We used a billet Cam with a cast gear. He has almost 12k miles on it so far. Not a single problem. Lash stays solid to the point where he only checks it a few times a year, timing stays the same.

If you can spend the extra couple dollars for a cast gear. Go for it.

As far as mopsr, I have a guy using a steel gear without problems, just make sure you have plenty of oil there. Depending on oil pump and how much oil pressure you are running can effect the life of the gears significantly.

[Flo]

where can you find "cast gears"? Arent the "regular" production gears machined from some type of cast iron?

[Geoff2]

Use a Melonized gear, you will be fine.

Lunati make the Melonized dist gears, they call them ' Everwear', suitable for all cam cores. Not sure if they make them for the BBM.

[Flo]

no "everwear" gear for Mopar....