2 gp 38 Diesel Engines running in sync?

[lionelsoni]

Frank, I'm afraid you did more work than you needed to.  For anyone who wants to try it, you don't need the switch to disconnect the unused e-units.  Just cycle those locomotives into neutral and switch off their e-units.  In the neutral position, all the e-unit connections to the motor are open.  Then connect the tethers.  Three wires are the minimum you need--field and two armature wires.  However, a fourth wire to bus the pickups is a good idea; and a fifth for the common wouldn't hurt but is probably overkill unless the locomotives have few wheels.

[brianel027]

Mike, I can assume that your GP-38's are lower-end Lionel locos. That is that they are non-command control locos with dual can DC motors mounted in the trucks.

First off, the motors used in these locos are made by Mabuchi, and both Lionel and K-Line used the identical same motor, although differing gears and circuit boards. Alhtough the gears on the Lionel and K-Line locos (like the K-Line Alco FA, S-2 and MP-15) are practically identical in function, they are incompatible because of mounting size of the main gear.

I run locos made by Lionel and K-Line together and have done so for over 16 years with no problems. What Lee talks about above could be more of a probelm if pairing up a Williams loco with one of your Lionel GP-38's, or a postwar Lionel loco with an open frame AC motor and a mechanical e-unit (which used much more power than your modern GP-38's).

Here's the test you want to perform:

Set up the locos so they they both run forward and then use the lock out switch on the underside of the loco and lock them both into forward. Put both locomotives on the track together with a little bit of distance between the two of them, and then turn on the power. See how consistantly they run with the space stying the same between the two locos.

You see, Mike no 2 DC can motors run at the precise same exact speed. This is true of dual motors on the same loco. You amplify the potential problem by pairing up another loco. So what you want to do is to match up locos that run at relatively the same pace. Otherwise you will have what Lee talked about above, where one loco is working harder than the other, which can cause one loco to wear out sooner than the other.

These lower end non-command DC can motored locos are my area of expertise, because they're pretty much what I run, give a take a few exceptions.

[ChiefEagles]

Older Lionel engines can be run together.  I ran three and one dummy for years.  I had a teather between the three powered units.  I wired the teathers to one EUnit.  I had switches in the frame of  two units to disable their EUnits and "switch" the control to the one EUnit.  This allowed me to pull long trains and operate them as usual.  Teathers are easy to buy now and would make it easy to operate.  When I wanted to seperate the engines, I "fliped" the switches and they went back to their own EUnits.  This was command control type lashing before command control.    

[Anonymous]

There is an old method used to run two or more engins from any manufacturer together. It is not used much any more since it is cumbersome but it does work. Place all the engins in question on the track but not connected to each other. Add cars to each engin until you reach the total train length you want and the engins all run at the same same speed and at the speed you are looking for. This evens the load out so each engin runs at the same speed under load. Now you can connect the engins together and connect all the cars together and run the train without problems. This works with engins from any manufacturer but is most usefull if you are setting up a unit train. Adding or removing too many cars can upset the load.

[phillyreading]

Hello Mike,

Running two GP 38's should be no problem as long as both are from the same manufacturer and within a year of production of each other, mainly because of the electronic circuit boards and motor design. The motor design is more of an issue than just circuit boards as one run may have a four pole can motor while another may have a five pole can motor, problem here is that you can not open a can motor itself to find out. Basicaly one engine may outpull the other and burn out a motor, so that is why the motors need to be matched as close as possible.  Also do not run two engines together from two differant manufacturers because of gears and motor problems may happen after a few months.

Lee

[Buckeye Riveter]

I would suggest that they be well broken in before you run them together, but then there is no problem that I know of.

[tcripe]

Mike,
 Should be no problem - I have lashed up the GP-38 with Lionel's two-motor RS-3, which is virtually identical to the GP-38 beneath the shell - with no troubles.
- Terry

[Anonymous]

Hello Thank You to everyones great input to all the forum topics.  I have a question regarding modern engines.  What i would like to do is run 2 powered engines together instead of using a dummy engine.  Both with the e units on forward only.  Can you tell me if I run any risk of damaging the engines?  They are both GP-38 modern Lionels.    Thanks again for the great info!

Mike