The different experimental airplane I lost a cylinder a couple of different times due to the piston skirt banging on the crankshaft unknown to me I was supposed to have filed the piston skirt down to the ride bearing sleeve. Only about three thousandths but it was enough! Near plans claim I'll want from a thousand feet per minute down to 500 feet per minute but was not really a worry. This was on a Volkswagen 2180. The old Volkswagen might have its faults but it is a very predictable motor and I trust it more than I do some aircraft engines! Good day all and keep firing on all cylinders the ones in your brain and the ones in the airplane! Doran Jaffas N186RC Central Lower Mich.