The size of 2 1/2" scale (on 7 1/2" gauge) is what we are looking for and will not follow a specific prototype since the look of the SW1200 is what we wish (single exhaust and engine house lower than cab height). The later version utility gasoline engines being a slanted design is lower but wider than the earlier L head vertical engines. The wider cab of the 2 1/2" will accommodate a larger more powerful late model engine. Maybe we should start by building a small flat head inline six cylinder engine... joking of course - if I had another 7 or so years to dedicate to the project I would do just that... Darn shame being practical when model building is such a hindrance! I have a small two cylinder 4 cycle strut pump engine that may work but I don't believe those engines were intended to do hard work for any length of time - get the plane landed on a down and locked landing gear strut...
The intent is to have a locomotive that is ready at a moments notice but can run for long periods - with fuel.
Thanks for the reply's!
bc