EricB, Yep, I just got a little lazy last night and confused the two. I started looking up densities and wasn't having any luck, so I went to a known site for specific gravities and forgot to switch back. I came up with volume of 14.5 cm^3 for the 2-8-2 with the dimensions given. The material would still have to be about 6.5 times denser than tungsten. Lou D, I was totally understating about the motor. I do know how to get 400 HP out of a device the size of a soda can: pure hydrogen peroxide pumped through a platinum catalyst.:tb-biggrin: Hydrazine is about 10 percent stronger, but is nasty stuff. But we're talking rocketry here, or auxiliary power units for fighter jets.
Oh,well,sure,if ya wanna do it THAT way,LOL!![Ever tell ya the story about the time I was running a jet engine I built from 2 turbochargers in my workshop at on of my jobs I had,and the boss walked in? I told him it was a bearing heater to get stuck bearings out of huge compressors I used to work on..He gave me a raise..]
You know, that thing would probably pull even more if you removed the rear worm gear. Y'all let me know when you get to the point of installing a miniature fission reactor in a Kato Mikado, I want to be several states away from wherever it is...