Lionel 2020 variations question

Normally, a 2020 turbine with an e-unit lever will have a motor with a worm cut into the end of the armature shaft. The motor is mounted on a tilt so the shaft goes down into the chassis, so the worm can turn a gear mounted on the rear axle.

On 2020's this motor should not have jacks.
In fact, the brush plate with jacks from the prior year won't fit unless the solder lugs are bent or trimmed.

If the solder lugs are not trimmed or bent for clearance, then someone may have replaced the brush plate with a 671R brush plate. This plate was made for the 1947-49 671R electronic locomotive. The solder lugs are shorter, and don't need trimming.

Someone may have just mounted a 2020 cab on a 671R chassis. The 671R was the electronic turbine. the 1947-49 models had both an e-unit lever, and the brushplate with the mini-banana jacks.

Are the jacks wired up?

C.W.  Did the 761R have the atomic motor which I believe is a double worm gear?

Bum

The 1946 model of the 671R had double worm drive.

The double worm drive engine should not have an e-unit lever. just the jacks.

The 1947-49 model of the 671R had the slanted motor I described above, with both an e-unit level and the jacks.

The 1947-49 models of the 2020 and the 671 should have the slanted motor, a e-unit lever, and no jacks. The only difference between a 1947-49 671 and 671R is the brush plate.

The 1946 2020 and 671 engines are the same, differing only in the number printed on the cab. I guess the 2020 may have come with a 12 volt smoke bulb, and the 671 may have come with an 18 volt smoke bulb. I'd have to look that up.

The only difference between a 1946 671 and a 1946 671R would be the electronic control decal.

I'm attaching a photo that shows the atomic motor plate and if you look beyond you will see the lever on top.  That is what's confusing about this one.

Nick

That motor appears to be on a slant. So the locomotive is a 1947-49 model.

I cannot see the tops of the solder lugs to tell whether they were trimmed or bent over. I also cannot tell if the jacks are wired, but I would assume not, because I don't see the jumper wire, which would be required.

If the solder lugs were trimmed  or bent over, then someone put a 1946 brush plate on your locomotive.

If they are not trimmed or bent over, then someone put a 671R brush plate on your locomotive.

If they are not trimmed, and the jacks are properly wired, then you probably have a 671R chassis.

By the way, according to the books, there are a lot of variations on the 1947-49 turbine drive wheels. I am not up on them.

The wheels are nickel rimmed and the plate appears to fit more snugly than the other two 2020 with atomics.  The two outer solder lugs are bent forward at the top, the center ones are not bent or trimmed.  There are no wires attached to the outer two and I can't see beyond the solder on the center ones.  I figured this would be a tough one so I think I'll just inventory it as having a modified plate and go on to the 671's as I'm already confused on them due to the different drivers.

Thanks again,

Bum

Bum, I would guess that you have a 1947 2020, with a replacement brushplate on it. That is just a guess, based on the picture. 

quote:

The two outer solder lugs are bent forward at the top, the center ones are not bent or trimmed.  There are no wires attached to the outer two and I can't see beyond the solder on the center ones.

As Train Doctor wrote, it sounds like someone replaced the original brush plate with a 1946 Brushplate.  So yours is a 1947-49 model.