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

Hey Ben,..agree con rod Needs a much lower friction bearing arrangement with traditional oiling Hole thru con rod...Also, I presume the shallow piston ring groove Pre-Loads the Rubber O-ring Tension against cyl wall for full time sealing ? ...Even when Not needed for Coasting !  Try something like a Deeper Groove for Less O-ring tension pre-load (and Less friction) & drill piston Top Gas Port Holes thru to Behind O-ring protective thin steel Backer Strip !  You now Only have O-ring Drag during Active Compression stroke or firing "hit" stroke With far Less Coasting O-ring Drag !  ...The Gas Ports would also let your previous suggested,  Lower friction, Rigid Teflon piston Ring idea work better ... Piston Gas Ports, ...it's the current hi perf lo drag power plan !!! .....Keep trying ideas,.....tom.