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

   I should explain how I use this thing. After the boiler reaches full pressure, and the engine is belted to the brake, I run the engine at full power while tightening the friction nuts . I tighten the nuts until the engine stalls , and record the maximum scale reading in ounces. Since the distance from the pivot point to the scale is three inches, I multiply the scale reading X 3 . I think that should yield torque in inch-ounces. I use the same size pulleys on my engines as well as the brake to get a fair comparison between engines . There are some problems with this procedure . The first problem is the fact that these small boilers cannot maintain full boiler pressure under full throttle settings . As it takes some time to perform one of these tests , steam pressure is constantly falling . The second problem is belt slippage . When you provide enough belt tension , the resistance builds , and affects the test reading . But hey , it is only a toy and is fun to build and use , but also a way to do some interesting testing as well.

D. E. Jones