tapered cylinder piston fit

pkrankow wrote:More or less.  

Every tapered Cox piston/cylinder set I have (well, 4 that I have checked) when separated from the engine the piston pushes past what would be TDC to about flush with the top of the cylinder, so it pushes past about the space of the glow head threads.

When the piston is "clean and dry" and attached to the crank it should not hang up or stick.

Phil

I have quite a number of old stock Tee Dee-s that came as new with tapered piston/cylinder fit but after a couple of hours run they all wear down to a normal fit. It does not necessarily mean loss of compression..some of my TeeDees have more than 50 hours of runtime on them and work like the original with excellent compression. The castor varnish built on the cylinder inside wall self-cures the engine wear so if you allow some run-in time with rich fuel, then keep the engine clean and use castor as lube instead of synthetic oils all times, a COX seems to be undestructable as far as the piston fit is concerned. COX engines die rather with the crankpin wearing off.