Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

..... Serious Engineering drawbacks!

"Serious" 

It’s sort of an apples versus oranges decision. The H75 copies the Holt World War-I tractor/tank engine with separated cylinders, exposed pushrods and valves (and crankshaft with the side panels removed) that can run and idle at nearly scale rpm. Many of the moving parts are exposed and visible just like the original. The Toyan is a model of nothing. It follows the concept of the overhead cam V8 design and was created in CAD and machined from stock without castings. It doesn’t appear to have an active ignition system but instead uses glow plugs, so it needs to burn model airplane fuel and idle at a very high rpm to keep the plugs hot. Other than the revolving timing belt and pulleys there isn't much to observe when it runs. The primary feedback you get from the Toyan is noise, and its sound does not replicate the loping exhaust note of a 4-stroke V8. Obviously, Toyan’s engines would be far more practical for powering an RC model than Jin’s detailed museum gems, if that is what you are after. It’s all about whatever flips your switch.