Help pulling and pressing wheels on MPC steam

[cwburfle]

Thanks for your answer.

The 249 had a double wound field and a 2 position e-unit.
I don't know whether postwar and modern era 2 position e-units or motor fields are wound with the same gauge wire.

I have put together locomotives using similar postwar motors and modern era shells. Since the motors were sitting in a parts box for many years before they were used, I couldn't tell you which ones they were.
I recall having to install a three position E-unit with the lever pointing down because the shells did not have an e-unit slot. Don't remember whether they had double wound fields.
They ran nicely. They are no longer in my posession.

[cando614]

My experience with the MPC-era 4-4-2s is that their motors tend to run hot.  After a period of time they slow down or even stop and refuse to budge.  The 2-position E-unit (which should be bulletproof) gets balky.  I attribute this to undersized wire in the double-wound field and armature, also possibly the brush springs.  The original MPC motor has one rubber tire on the rear geared wheel.  These motors have aluminum sides which are readily visible in the wide gap between the drive wheels.

The 249 has a "metal" scout motor (which has nothing in common with the much-maligned regular Scout motor, except its dimensions.)  Based on my experience with the 1615, these motors have no issues with extended running, even when asked to carry a heavy die-cast body.  I happen to have the motor from a 249, so the E-unit lever is already in the correct place for the 8304 shell.  However the motor from a 250, 1130, or 2034 would also work.  None of these motors have rubber tires as stock.  The frames are black steel, which doesn't detract as much from the prototypical appearance.

I have several MPC motors lying around.  The early MPC 0-4-0's and 2-4-0's used a similar motor/chassis to the 8304, however with no rubber tires.  Because I DON'T like rubber tires, I'm planning to steal the rear wheels and axle from a different MPC loco.  The boss/tapped hole for the driving rod screw is the same.

The end result should be an MPC 4-4-2 with postwar performance and reliability, no rubber tires, and all of its original valve gear.  I'm not the first one to have this idea.  I bought one like this on eBay a few years ago, but whoever performed the transplant surgery botched it.  It wobbled and eventually ate up its bearings.  I'm trying not to repeat his mistakes.  Thanks for your interest and advice!  -Ted

[cwburfle]

Gotta ask: What is the advantage of putting a 249 motor into an 8304 if you are swapping the drive wheels?

 

[KRM]

Ted, I have had some good luck with traction tires. Many of the brands other than Lionel have no other options and some of my Williams engines are the best pullers I have. But looking at the lionel parts site, they do not sell the wheels alone for the modern General. You have to by the bottom frame with wheels so that would not cut it. Maybe The Magnetraction parts from a post war 1872 General could be installed on the MPC 8701?

[cando614]

I would like to install the metal "scout" motor (from a postwar 249) into an MPC-era 8304.  The mounting points and E-unit lever on both of these motors are the same.  However the 249 was a Columbia 2-4-2 with only one main rod.  The 8304 is a well-dressed 4-4-2 having a main rod, connecting rod, and valve gear which I would like to reuse.

The MPC 4-4-2s didn't suffer from wobble, they had die-cast wheels in the pattern of a 2034 or 2018.  It was the small Hudsons, especially the 8206 that tended to wobble.

Whatever wheels I use need to be properly quartered and tapped for the connecting rod screws.  I also believe it would be easiest to reuse the MPC #3 hex-head machine screws and spacers.

 My experience with diesels matches yours--substituting postwar parts yields improved operation.  Postwar and MPC parts will usually interchange.  Once you get to 21st Century Lionel made in China, it's hit-or-miss.  

Personally I despise rubber tires.  If I get good at the pulling-and-pressing thing, I might actually replace the grooved wheels on some of my other locos with smooth ones.  If you want a non-permanent improvement in pulling power without changing wheels, search for information about a product called "Bullfrog Snot."

Thanks and keep them coming!  -Ted

[KRM]

 This is interesting question and I can't tell you a good answer, but it brings me to ask another question. BTW what Loco are you working with?
 In my small experiences with MPC era engines and drive wheels,,, I have a few but not a lot of them,, but they all share one common, Their wheels are not true and they wobble. So if it were me I would be looking at replacing wheels with anything but those. JMHO. Stick to the iron postwar wheels if you can. I replaced my drive trucks on my MPC New Haven Powered F3  A-Unit # 8851 with post wat F3 drive trucks and it was a great improvement and got rid of the wobble.
 That in mind,,, Would anyone know if you can put modern General wheels on a MPC general to get the advantage of the traction tire???

[cando614]

I'm about to begin a project which might involve pulling the driving wheels and axles from a small MPC-era steam loco and pressing them into an equivalent postwar chassis.  The axles should fit, because both have a 2026 part number.  However, I think I've read that the MPC die-cast wheels are difficult to pull, and a tighter fit on the axles than the sintered iron postwar wheels.  I have access to a puller and Hobby Horse press for this job, but I've never attempted this kind of repair before.

For the record, I first tried re-tapping the postwar wheels to accept the MPC-era #3 hex head machine screws needed for the rods and valve gear.  But frankly I don't have a lot of experience tapping holes either, and I wasn't successful.  I found the sintered iron wheels prone to crumbling, and the depth of the tapped hole is somewhat critical.  So transferring the MPC wheels and axles to the postwar chassis might be the most promising approach.  

Does anyone advise dressing the hole in the MPC wheel before pressing it back on?  Would heating it in the oven to 450F make a difference?  My main concern is getting the wheel on true so the loco doesn't wobble or hop.  Also, should I use the original postwar bushings, or the MPC ones?  What kind of advice does this board have for a heavy repair newbie?  Thanks!