Lionel smoke unit question

[tiloco]

Hi everyone, I am new here. Not necessarily new to trains. (used to collect AF in the 60's-70's, but got out of it for awhile, now starting on Lionel, etc). I recently purchased a Lionel Southern Crescent (8702). In the process of replacing the "sounds of steam" with "railsounds", I noticed on an exploded view of the engine that I am missing the "smoke piston return spring" (# 8600-20). No wonder the smoke barely gets out of the stack! So while I was knee deep in the engine, I purchased a new smoke unit, piston, and spring. My dilema? I cannot figure out where the return spring connects to! The exploded diagram really doesn't clearly show the location. There is a small hole in the smoke piston lever that looks like it would accept one end of the spring, but the other end doesn't appear to have anywhere to connect. Smoke unit is # 8600-42, piston is # 8600-41. I am hoping someone here has the same engine and can explain to me how the return spring connects? Sorry to be so long-winded, but I wanted to give as much info as possible. I look forward to learning alot about my newly rediscovered hobby on these forums! Thanks for any help, Tim 

[ADCX Rob]

It doesn't connect.

It just sits on top of the piston.  I kid you not!

Rob

[tiloco]

Rob, thanks for responding. But I cannot see how this spring would sit on top of the piston. It is not a normal type spring as you would guess. It has a preformed "S" at one end, and an offset hook on the other. The exploded view from the Lionel parts diagram shows it "horizontal", as though it attaches to something outside of the piston/chamber. This is the smoke unit that has the mechanical "chuff" contacts attached to the piston and chamber. Not doubting you, but I don't see how it could work as you describe. I think I know the type you mean, a regular coil spring that forces the piston down, but it is nothing like that. Maybe I am just totally missing something? Thanks again, Tim

[RockIsland52]

Welcome tiloco! 

Jack

[ADCX Rob]

tiloco

Rob, thanks for responding. But I cannot see how this spring would sit on top of the piston. It is not a normal type spring as you would guess. It has a preformed "S" at one end

 

That spring.

That might not be needed if the right side crosshead pulls the smoke lever bellcrank(and the piston down) on the backstroke.

Otherwise, it looks like the "s" hooks around the smoke lever bellcrank and the offset hook inserts into a hole in the motor frame.   A 2026-44 spring can be placed on top of the piston to do the same job.

Rob

[tiloco]

ADCX Rob

   A 2026-44 spring can be placed on top of the piston to do the same job.

Thanks Rob, I will try the spring you mention. The right side crosshead does pull the piston bellcrank on the backstroke, but the piston may be getting hung up in the cylinder. It only moves about 3/16", which is probably why the smoke just kind of "falls out" of the stack. I've already tightened the retaining arms in the crosshead bracket to limit the up/down travel of the piston rod as they had quite a bit of slop in them. I would assume that the 2026 spring is weaker than the spring under the piston? Otherwise they would counteract each other. While I'm waiting for the spring I will have to finish shoe-horning all the railsounds and CAB units into the tender. I'll let you know how I make out with the spring. Thanks again for the help.

 

Tim

 

Jack....thanks for the welcome!

[sir james I]

The only return spring lionel used sat on top of the piston. An 8600 never had a spring in it but can be used, later smoke units had a piston with a spring held ball bearing to let air in through the bottom and the piston spring was attached to the piston.

[tiloco]

sir james I

The only return spring lionel used sat on top of the piston. An 8600 never had a spring in it but can be used, later smoke units had a piston with a spring held ball bearing to let air in through the bottom and the piston spring was attached to the piston.

 

Thanks for the input Sir James. I don't doubt your knowledge, but I am looking at an exploded view of the 8600/8702/8801. It shows a (36) spring, part # 8600-20, and lists it as a smoke unit return spring.I have the spring, but the diagram does not clearly show where it attaches. It seems to be a rather weak spring so I am sure it isn't under a lot of stress. This is a NOS smoke unit I am installing, but it acts just like the old one (piston barely retracts). Maybe I am just looking at it totally wrong? I am thinking this spring should help pull the piston out of the cylinder, but cannot see any way it would attach. Again, thanks for your input.

Tim

[sir james I]

I do not know of ANY lionel engine that had a return spring attached outside the piston chamber. On MPC engines that had sound of steam the piston is plastic with a lip to contact a wire to the sound board in the tender. Some had a spring attached to the rod that moves the piston but that too is part of the smoke unit.

[cwburfle]

Your spring is shown on page 3-31 of the Modern Era Lionel service manual.
As you've written, It's hard to tell how the spring is installed from the picture.
If the engine was mine, I'd leave it out, and install the 2026-44 spring in the piston chamber, as has already been suggested.

[tiloco]

cwburfle

Your spring is shown on page 3-31 of the Modern Era Lionel service manual.
As you've written, It's hard to tell how the spring is installed from the picture.
If the engine was mine, I'd leave it out, and install the 2026-44 spring in the piston chamber, as has already been suggested.

 

Thanks cw, I plan on doing just that. It just bugs me that I can't figure out where a simple spring goes! I have the manual you speak of and have been alternately staring at the manual and engine...to no avail. I hate it when a machine stumps me! Thanks again. 

[ADCX Rob]

How did this work out for you?

[tiloco]

Hi Rob,

Actually, adding the spring as mentioned did not do a whole lot for the smoke unit. It still has a lethargic "puff".