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

Hi Ben,...a Tach IS nice but Not required for our H & M  Common interest Improvement measured progress purposes...Your Existing cell phone device using Digital Stopwatch mode & Counting Hits per min + Video Camera Record mode at 1/4 or 1/8 Slo-mo speed & counting Audible "Huffs"(coasting strokes) between Hits does same + let's you Observe subtle Dynamic nuances (intake valve action, governor weights & Latch-out action, etc actions...The instruction sheet specing 95# (octane) fuel is a clue of near 10:1 CR way too high for realistic H & M Rpm as I don't plan to drive any accessories...4.5 CR is probably near optimum power hit to Flywheel inertia pump over & that's gonna require a good size piston top cut...I plan to fit the piston skirt with some small Teflon clearance "Buttons" which combined with the upper O-ring, should Totally remove all piston to liner Metallic physical contact friction & sliding scuffing.....tom