When your hot your hot even if the pump drive is not

[Jadaharabi]

Am I to assume that Magnum intermediate gears are pinned to the shaft?

I think the one that's tapered pandan heart and tip is probably something someone else threw in there at some point possibly when the stock one failed

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Went back to clean up that post and wiped out half of what I was trying to say.
Anyway these are all four out of an LA not a magnum. I don't have any Magnums in this garage at the moment.
The LA and the Magnum gears are two different Metals I have to find where I studied that and then I will post it.
You may very well be right that somebody for some reason had to replace that shaft and in so doing put a hardened one in it.

Looks like chocolate is kicking butt in the polls.

 

[Jadaharabi]

From a Larry Shepherd book.


Cam Gear
Magnum engines use a forged steel cam and special hardened oil pump drive gear that mates to it.

These look similar to the standard A-engine gear/drive, but they should not be switched. You cannot use a standard A-engine intermediate shaft and gear on Magnum cams.



The camshaft drives the oil pump and the distributor off the gear at the rear of the cam. The gear actually drives an intermediate shaft. For max performance it is a good idea to upgrade this shaft to a race unit. The one tricky part is roller cams. All mechanical roller cams are steel; the Magnum’s hydraulic roller cam is a steel alloy.

Written by Larry Shepard
Mopar Engine Performance Guide: Camshaft, Lifters and Cam Drive - Mopar DiY

 

[gzig5]

To the original question, it really depends on the material, how well it will harden. The process I use for through hardening smallish parts made of a treatable steel alloy is to heat until non-magnetic, quench, polish, temper heat to light straw or blue color, bury in dry sand to cool as slowly as possible. Heat to non-magnetic means just that, you heat it until a magnet will no longer attract to the hot end, usually a orange to bright orange color.

You can also surface harden (case harden) a material that won't through harden. This is done by adding carbon by heating the part and dunking it in a hardening compound like Kasenite or Cherry Red. Simply heat the part, dunk in the powder, repeat until well coated, heat and hold at red temp for a time, quench and clean off the debris. This leaves a hard, slick surface a few thousandths of an inch deep but the original softer core of the parent material.

 

[MopaR&D]

Am I to assume that Magnum intermediate gears are pinned to the shaft?

I think the one that's tapered pandan heart and tip is probably something someone else threw in there at some point possibly when the stock one failed

Magnum gears are not pinned I have one in my garage I'll post a pic. The only way I could see a difference with an LA drive gear is the gear itself is slightly shorter and has a bit of a different shape to it the way it "tapers" down to the shaft, but it's definitely still not pinned.

My understanding of cam materials after talking with Jim at Racer Brown is the factory roller cams have a very thin surface-hardening but I don't know if the material itself is different; I asked if he might take my stock Magnum cam as a core and he didn't want it, said the hardening is too thin to do a proper regrind unless it's extremely mild. If that info is useful at all lol. However he assured me that my stock Magnum dist gear would work fine with the cam he custom-ground from a blank core.

 

[Jadaharabi]

More Larry info

Oil Pump Drive
Another concern relates directly to the camshaft you use. If you plan on using a hydraulic roller cam or a mechanical roller cam in your engine, you should have an intermediate shaft, which uses a bronze gear or an aluminum-bronze gear. It is gold in color so it is very easy to determine if you have one. It should be pinned to the shaft. The problem is that these roller cams are made from steel and the production gear wears out very quickly when run against a steel gear. The bronze material solves this metallurgy problem.

Magnum engines, which already have a hydraulic roller cam made from steel, are tricky. Chrysler engineers solved the steel problem by alloying and heat-treating the gear. My problem is that the finished production part looks just like the A-engine production part, which should not be used with roller cams. The Magnum part should work with all rollers, but you might talk to the cam experts (Comp Cams or Crane) to see if they have encountered any issues. If in doubt, use the Magnum shaft for the hydraulic cams and the bronze gear with the bigger cams.

The stock part doesn’t typically break by the gear. However, the gear is only pressed onto the shaft, so in high- performance applications, the gear (black or dark gray) can slip on the shaft. Moreover, the small end of the shaft just above the oil pump hex can fail. For performance engines, the first concern is to get an intermediate shaft that has the gear pinned to the shaft. These are available from Mopar Performance or Milodon; both use a heavy-duty shaft.
If the engine is being built for the street and for durability (high mileage), you might consider the Milodon bronze gear, which claims premium material for better wear resistance.


Mopar Engine Performance Guide: Oiling System - Mopar DiY

 

[MopaR&D]

More Larry info

Oil Pump Drive
Another concern relates directly to the camshaft you use. If you plan on using a hydraulic roller cam or a mechanical roller cam in your engine, you should have an intermediate shaft, which uses a bronze gear or an aluminum-bronze gear. It is gold in color so it is very easy to determine if you have one. It should be pinned to the shaft. The problem is that these roller cams are made from steel and the production gear wears out very quickly when run against a steel gear. The bronze material solves this metallurgy problem.



View attachment 1715285938


Magnum engines, which already have a hydraulic roller cam made from steel, are tricky. Chrysler engineers solved the steel problem by alloying and heat-treating the gear. My problem is that the finished production part looks just like the A-engine production part, which should not be used with roller cams. The Magnum part should work with all rollers, but you might talk to the cam experts (Comp Cams or Crane) to see if they have encountered any issues. If in doubt, use the Magnum shaft for the hydraulic cams and the bronze gear with the bigger cams.


View attachment 1715285939
The stock part doesn’t typically break by the gear. However, the gear is only pressed onto the shaft, so in high- performance applications, the gear (black or dark gray) can slip on the shaft. Moreover, the small end of the shaft just above the oil pump hex can fail. For performance engines, the first concern is to get an intermediate shaft that has the gear pinned to the shaft. These are available from Mopar Performance or Milodon; both use a heavy-duty shaft.
If the engine is being built for the street and for durability (high mileage), you might consider the Milodon bronze gear, which claims premium material for better wear resistance.


Mopar Engine Performance Guide: Oiling System - Mopar DiY

So does that mean because the Magnum shafts are hardened (tee hee) so the gears don't wear that the tip would also be a bit stronger and harder to break off? Still thinking about testing them out myself...

 

[Jadaharabi]

So does that mean because the Magnum shafts are hardened (tee hee) so the gears don't wear that the tip would also be a bit stronger and harder to break off? Still thinking about testing them out myself...

..
One way I read it says it that shaft on the Magnum is already hardened and then you read further down and and he's telling you that you need to replace it with one with a hardened end. I think what he's actually saying is that the stock Magnum shaft is hard enough for a stock pump but if you're going to high volume you should go with a aftermarket one.

 

[318willrun]

I've always understood it this way.

• If you use a magnum cam, you need a magnum oil pump gear/shaft
• If you use a roller cam from a LA, you need a LA oil pump gear/shaft.

I'll tell you, though, I've never upgraded a cam in a Magnum motor... yet.
But, I do have a '89 LA roller cam I am going to use in a Magnum because it has the fuel pump eccentric. I'll use the LA oil pump gear/shaft.

 

[Jadaharabi]

I've always understood it this way.

• If you use a magnum cam, you need a magnum oil pump gear/shaft
• If you use a roller cam from a LA, you need a LA oil pump gear/shaft.

.
If you use an l a roller cam those I believe our Billet steel cams and you need a bronze Gear with them.
From what I've read the Magnum roller cams are forged Steel and they use a special treated gear on there intermediate shaft.

 

[318willrun]

.
If you use an l a roller cam those I believe our Billet steel cams and you need a bronze Gear with them.
From what I've read the Magnum roller cams are forged Steel and they use a special treated gear on there intermediate shaft.

Ok, but I pulled the cam out of a '89 roller 360 and I don't believe the gear was bronze.....???? been a while, I might have to go digging.

 

[Jadaharabi]

Ok, but I pulled the cam out of a '89 roller 360 and I don't believe the gear was bronze.....???? been a while, I might have to go digging.

.
The roller Motors use a forged roller cam the gear is special treated not bronze.

 

[318willrun]

.
The roller Motors use a forged roller cam the gear is special treated not bronze.

Ok, so when I go to put that LA 360 roller cam in a magnum, I use the LA gear? or the mag? or it doesn't matter??

 

[Jadaharabi]

The 89 roller uses the mag gear.

 

[Jadaharabi]

Okay here's my latest pictures with measurements I want you to notice the different thicknesses of the gears. In the end the gears themselves are the same thickness overall.
But you will notice that the gear part that has the teeth have different thicknesses. Except for the two that are together one of them is pinned and one isn't and they have the same thickness of gears. Then the other pinned one is wider on the teeth.

By the way the one in the Middle with no pin in it I just pulled out of a 360 Magnum 5.9, whatever you want to call that thing.
What I find interesting is the thickness of the gear teeth themselves on the hardened shaft and the 5.9 are the same. And the standard shaft la Style has a wider tooth then the others. But they all are within a thousand or so of each other on total depth.

 

[nm9stheham]

Could the 'thicker' appearing teeth simply be due to them being cut shallower or differently angled on the sides?

 

[Jadaharabi]

Could the 'thicker' appearing teeth simply be due to them being cut shallower or differently angled on the sides?

.
Probably cast by a different manufacturer would be my guess.

 

[MOPAROFFICIAL]

Okay here's my latest pictures with measurements I want you to notice the different thicknesses of the gears. In the end the gears themselves are the same thickness overall.
But you will notice that the gear part that has the teeth have different thicknesses. Except for the two that are together one of them is pinned and one isn't and they have the same thickness of gears. Then the other pinned one is wider on the teeth.

View attachment 1715286080 View attachment 1715286081 View attachment 1715286082

View attachment 1715286083

By the way the one in the Middle with no pin in it I just pulled out of a 360 Magnum 5.9, whatever you want to call that thing.
What I find interesting is the thickness of the gear teeth themselves on the hardened shaft and the 5.9 are the same. And the standard shaft la Style has a wider tooth then the others. But they all are within a thousand or so of each other on total depth.

The bottom pic, right. That's a MP hardened tip gear. They have a yellow overspary look on the side. Every single one I've bought looks like that.
I have a magnum roller I'll dig out to see what it's made of... but the trick a lot of guys do when they want to run a roller but don't want to deal with a bronze gear wearing ... is to use an iron core.

 

[Jadaharabi]

Could the 'thicker' appearing teeth simply be due to them being cut shallower or differently angled on the sides?

.
The inner gears are machined underneath them where the thicker gear is not. They have removed part of the gear itself from the bottom of the teeth.

Okay so the hard shaft and gear assembly has the same gear as the 5.9 Magnum. They both have that machine area at the bottom making the teeth narrower.

 

[Jadaharabi]

The bottom pic, right. That's a MP hardened tip gear. They have a yellow overspary look on the side. Every single one I've bought looks like that.
I have a magnum roller I'll dig out to see what it's made of... but the trick a lot of guys do when they want to run a roller but don't want to deal with a bronze gear wearing ... is to use an iron core.

.
By iron core you mean the the roller cam has an iron core instead of steel?

 

[MOPAROFFICIAL]

.
By iron core you mean the the roller cam has an iron core instead of steel?

It's been a min since I've looked at one, but factory magnum cams, yes.. or cast steel, but I'm going with iron. I'll look.

 

[RustyRatRod]

There's more to it than being hardened. There's also the different transition on the shaft. Just buy the right one ya cheap bastid.

 

[MopaR&D]

Abodybomber told me once he successfully ran a retrofit hydraulic roller cam meant for LA engines in a Magnum block but he didn't mention what he used for the dist drive gear, it's a shame he can't chime in with his experiences

 

[jos51700]

My instinct is to say, just buy the right one, it ain't worth eating up a motor; but it may be disco'd.

I'm thinking you don't want to harden the whole tip. It'll be brittle and just snap off if it gets a little crack. Case hardening is what seems like you'd want, so the core is still tough and not brittle.

But I'd just buy the right one if I cared enough about a motor to be concerned about the pump drive. Someone else did the r and d a long time ago, no need to reinvent the wheel here.

And that radius taper of the mp piece is going to get you a lot further for durability than the hardened tip.

 

[nm9stheham]

I'm thinking you don't want to harden the whole tip. It'll be brittle and just snap off if it gets a little crack. Case hardening is what seems like you'd want, so the core is still tough and not brittle.

And that radius taper of the mp piece is going to get you a lot further for durability than the hardened tip.

The hardening is for a different possible failure that the tapering does not solve; the problem of the shaft's hex tips rounding off. The tapering does nothing for that.

 

[Daves69]

........But you will notice that the gear part that has the teeth have different thicknesses.....

If the gear OD or lead in angle is smaller, would the tooth end be larger?
You might try measuring over wires or ball bearings to compare differences if it's critical to you.