After looking at that, I think I understand why whoever had this engine converted it for an MTH smoke unit.

Thank you for the reply but it looks to me like 620-8072-220 is only the heater element. I am trying to find the entire smoke unit that goes in that engine. Number 610-8051-200 goes to the B&O EM-1 which is also an Odyssey and I think the same unit fits the C&O (cab # 3004) T4 but I'm not 100% sure and Lionel doesn't seem to list it.

As a long time O-Scale choo-choo man, I'm sure this question has been asked before but as a new forum member, pardon me for asking it again. Lionel includes a couple of replacement tires in the box with new engines but, they do not include the Traction tire P/N in the manual. The only Lionel chart I could find is pretty ancient and does not include "Legacy" or even some of the "Odyssey" stuff. MTH provides up-to-date charts on the internet and their tires are very good. I know that a scale engine of the same type by any manufacturer should match in diameter but there are other considerations such as thickness (wheel groove depth) and width. In fact, I have a Weaver Brass "Broadway Limited" streamlined Pacific (PROTO-2 UPGRADE)  that has traction tires that are only half the width of the wheel and they don't provide replacements. I've gotten pretty good using a razor blade. My question is, is there a fairly up-to-date chart showing which Lionel traction tire P/Ns will fit which Lionel Engines? I've inquired of Lionel LLC but as yet have no reply. For the record, I don't like traction tires anyway. They're a bigger pain then they are worth in my opinion.