PA28 Archer: engine write-off at 1200hr
Due to the poor location of the cam on top of the engine in a Lycoming, the oil drains from the cam and then it starts to rust.
One of the many design features of a Lycoming, to shorten its life.
Also there was some pre 1972 narrow width cams that wear quickly and are only TBOed for 1400 hours.
Lycoming say their engines have to be run 40 hours a month to make TBO and any failures are due to poor engine managment.
Not their poor design. They would say that
Note, all the design comes from the 1920s.
We lost an engine 240 hours with just about everything internaly
worn or breaking up, but it ran nicely, luckly found when pulled to check out a centre bearing crankcase oil leak.
We think we had an oil break down, running for the last 140 hours on Exxon Elite, I trhink the stuff is marginal and to thin.
Brian