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

Considering the H70 series engines serious design  (reverse cam timing, non-lubricated crank, rod & piston, etc,) issues & Not exactly built like a Swiss watch loose,.....Why would one expect the original Oem Cylinder groove & O-ring Dimensions + O-ring Shore A durometer to be anywhere Near functional sealing optimal ?? ....Fine tuning the original 2 groove cylinder O-ring ID/OD/Cross Section & Durometer selection will most likely correct the leaking issue.....2 x Bad = More Bad !!

JohnnyQ90 has a Video on YouTube where his new H75 leaked water. He removed the Cylinders and replaced the original (Undersized?)  O rings with 19 X 1.9 mm O rings and this fixed the water leakage problem.
 https://m.youtube.com/watch?v=-tuZeMifCoc

Expecting Ferrari while spending Ford money

Not a valid point at all, when someone like you makes a comment like that, it justifies companies like Microcosm charges people for a defective product then expecting them to pay to get a corrected part. No one is expecting Ferrari ( despite them having issues too) but if I pay for Ford I want Ford quality not some cheap Chinese knock off.

I have a simple solution for your ongoing engine dilemmas.  Don't buy them.

See that is where I disagree. I buy a low cost engine expecting to need to fix the details that bother me, but also expect it to run (not expecting a swiss watch, but functional) When a manufacturer has to deal with people demanding returns on a running model, they are forced to charge more per unit. So for those of us that want to take the time to make it perfect, it hurts to see the prices being driven up. For the people expecting a well tuned machine, they are let down because they are certainly not that right out of the box. For example, the chatter I found on the crankshaft of my H75 was totally functional, and the engine would run for a long time. It wasn't good enough for me, so I fixed it. For people that would never care that it was there, the engine is perfect. Why should all of the people buying these engines have to pay the extra cost of the manufacturer polishing these parts, when most people will realistically never run them long enough for it to matter? The manufacturer's obligation is to deliver a running engine, and there is no possible way for them to guarantee how long or how well it will run, because the operator must oil and manage it. I'm picky about my engines, but don't have the money for a meticulously made engine, and that is why I love the low cost engines. I can make them perfect in my own eyes, with my own effort. If you are picky about your engines, either get saving, or get polishing haha.