Cam and distributor gear compatibility

[matt030305]

Hey all, I can’t seem to find a straight forward answer for this and I was wondering if anybody would have one for me. I have an 01 magnum block and I recently purchased this camshaft from comp cams (COMP Cams 20-813-9 COMP Cams Xtreme Energy Retrofit Camshafts | Summit Racing). I was wondering if I could use the stock distributor gear from the magnum with this cam. Trying to save myself an extra $200-$260 for a bronze or melonized gear. Thanks!

 

[Kern Dog]

What matters is what the core material is that was used to make the camshaft. If it is cast iron, the stock gear is fine. If it is a billet steel cam, you need the different one.
You can tell a cast VS billet by the texture of the cam between the lobes.

See how that one is rough between the lobes? That is what a cast iron cam looks like.

Below is a stock type cam from a 1990 360, a factory roller engine with a Hughes reground cam:

Same texture as you usually see in an unmachined surface on a cast iron part.

 

[mopowers]

Hey all, I can’t seem to find a straight forward answer for this and I was wondering if anybody would have one for me. I have an 01 magnum block and I recently purchased this camshaft from comp cams (COMP Cams 20-813-9 COMP Cams Xtreme Energy Retrofit Camshafts | Summit Racing). I was wondering if I could use the stock distributor gear from the magnum with this cam. Trying to save myself an extra $200-$260 for a bronze or melonized gear. Thanks!

That cam is most likely going to be ground on an austempered ductile iron core. A stock-type iron gear will work fine with it.

The problem is if you call Comp and ask them, depending on who you talk to, they may mistakenly tell you it's a billet core requiring a melonized or bronze distributor gear.

 

[volaredon]

I've heard people talk about "melonized" a fair amount recently, have never heard that until a few months ago, honestly. What exactly is that?

 

[mopowers]

I've heard people talk about "melonized" a fair amount recently, have never heard that until a few months ago, honestly. What exactly is that?

To my understanding it's a heat treatment applied to a steel gear, making it extremely wear resistant.

The problem is that Hughes is the only place to buy one.

 

[matt030305]

That cam is most likely going to be ground on an austempered ductile iron core. A stock-type iron gear will work fine with it.

The problem is if you call Comp and ask them, depending on who you talk to, they may mistakenly tell you it's a billet core requiring a melonized or bronze distributor gear.

That’s what I’m worried about. I believe that the magnum oil pump gear utilizes a steel gear where the LA used the iron gear. Regardless I have both, I’m going to try to do some research to see if I can find the material of the cam.

 

[matt030305]

To my understanding it's a heat treatment applied to a steel gear, making it extremely wear resistant.

The problem is that Hughes is the only place to by one.

And it costs a lot of $$$ for such a small part

 

[matt030305]

Okay so 360duster said this. I’m going to get the metal tested on both (camshaft and both magnum and LA gears) to check the hardness to see what can be ran. Better safe than sorry.

their tech support sometimes is a pos.....i asked the same question, same answer. After discussing with other people i found these cams have a cast core.....easy to see. Then you´re ok with the stock cast iron gear. If it´s a billet core (shiny, machined surface everywhere) then you should use a special gear. Mine (xr286hr) is working flawlessly with the stock intermediate shaft.

Michael

 

[volaredon]

I have a few here I believe are mostly from magnum engines not LA. What's the difference here and any way to tell that difference by looking?
Is there any place to have an existing one treated with that melon process? What is to that process

 

[mopowers]

That’s what I’m worried about. I believe that the magnum oil pump gear utilizes a steel gear where the LA used the iron gear. Regardless I have both, I’m going to try to do some research to see if I can find the material of the cam.

I believe stock magnum and later roller LA distributor gears are iron. Pretty sure the stock roller cams are iron.

 

[crackedback]

Those cams use the stock gear. The retro is a replacement for the stock camshaft. They aren't cut on a billet core. Magnums use the same pump drive as the LA's

If you have a catalog handy, the retros do not have the distributor gear upgrade required footnote. The drag race solid rollers do. Might be a hint that you don't need a special gear.

I've done a couple of engines with these cams, none took a bronze gear. Unless they changed the material which I doubt.

 

[gzig5]

I've heard people talk about "melonized" a fair amount recently, have never heard that until a few months ago, honestly. What exactly is that?

Salt bath nitriding. Results in a very hard, very slick, very thin "skin" on the part. You can get just about any alloy steel treated and on a per part basis it isn't very expensive but doing one offs there is usually a setup fee and it's not so economical. They've been doing custom rifle barrels and it is $100-$150 per. Barrels last MUCH longer.

 

[matt030305]

I believe stock magnum and later roller LA distributor gears are iron. Pretty sure the stock roller cams are iron.

What I’m getting from this is both the magnum and LA distributor gears are made of the same materials and I should just pick the one in better condition right?

 

[volaredon]

So melonized = nitrided ?

 

[TT5.9mag]

Go to comps website.

https://www.compcams.com/products/c...f19re6xihRHllFmk36gMxyNS1cDSXQloaAoHxEALw_wcB

Type in the part number of your camshaft, then scroll down to “recommended components” and it tells you what distributor gear you need.

 

[360duster]

This information is just wrong.

 

[mopowers]

Go to comps website.

https://www.compcams.com/products/c...f19re6xihRHllFmk36gMxyNS1cDSXQloaAoHxEALw_wcB

Type in the part number of your camshaft, then scroll down to “recommended components” and it tells you what distributor gear you need.

View attachment 1716372928

That distributor gear part number (420) references a bronze gear. You don't need a bronze gear for the cam he bought. I've noticed some misinformation on their website. Comp's notorious for it.

What I’m getting from this is both the magnum and LA distributor gears are made of the same materials and I should just pick the one in better condition right?

If you're using a HV oil pump, consider getting a distributor gear with a hardened shaft like the Melling IS72. It's cheap insurance. O'reilly has them for like $60 last I checked

 

[gzig5]

If you're using a HV oil pump, consider getting a distributor gear with a hardened shaft like the Melling IS72. It's cheap insurance. O'reilly has them for like $60 last I checked

I agree on the IS72. I just got one from AutoZone for about $56 I think and last week on the dyno it was driving the HV72 pump in my 340 to 80 psi at 6000 rpm. Hardened hex end, and while the gear isn't pinned, I am confident it isn't going anywhere at my HP and RPM levels. I was going to pin it but the machinist said not to bother.

 

[TT5.9mag]

That distributor gear part number (420) references a bronze gear. You don't need a bronze gear for the cam he bought. I've noticed some misinformation on their website. Comp's notorious for it.

I agree, but you can always run a bronze gear on just about everything. It’s soft and it sacrifices itself instead of chewing up the cam. I think it’s comps way of covering their own ***.

 

[67Dart273]

This information is just wrong.

Which is wrong? Please be specific. What is "this" in other words?

 

[volaredon]

Which is wrong? Please be specific. What is "this" in other words?

His location does show Bavaria/Germany. Maybe they have something available that we don't readily have much like the Aussie guys do?

 

[matt030305]

That distributor gear part number (420) references a bronze gear. You don't need a bronze gear for the cam he bought. I've noticed some misinformation on their website. Comp's notorious for it.


If you're using a HV oil pump, consider getting a distributor gear with a hardened shaft like the Melling IS72. It's cheap insurance. O'reilly has them for like $60 last I checked

Just checked and my local auto parts store does have the Melling IS-72. It’s labeled as “hardened steel”. My question now is in what cases can a cam gear strip another gear and vice versa (aside from grinding against a softer material)

 

[mopowers]

Just checked and my local auto parts store does have the Melling IS-72. It’s labeled as “hardened steel”. My question now is in what cases can a cam gear strip another gear and vice versa (aside from grinding against a softer material)

The shaft is hardened steel. The gear itself is iron.

 

[mopowers]

Now that I think of it, maybe it's just the tip of the Melling steel shaft that's hardened.

 

[Clelan]

Is there a down side to the bronze gear, I expect it to wear more quickly, but how long should it last? I went by Comp's recommendation and put the bronze gear but my cam isn't billet.

Cley