LUBRICATION & TIMING


| May/June 1978



Diagram showing distortion of the piston movement

559 Sheldon Road, Palmyra, New York 14522

Well, here it is November the 21st and the shows are over for another year. And another wet one it was! At the Pageant of. Steam at Canandaigua, N.Y. we were nearly rained out, but it wasn't quite as bad as it was in 1976. At the Western New York Gas & Steam Engine Show at Alexander, N.Y. the mud was hub deep and the show was finally canceled. Let's hope 1978 will treat us with good weather at show times.

At nearly all the shows that I have been to, a too common sight is an engine belching smoke and running way too hot. If an engine is properly timed and the water hopper is free of any foreign material and not belted to anything, it should run at about 160 degrees. It's understandable that if an engine has new rings it will run hotter than normal. Lubrication of the piston is important. With the trip raised on the oiler, adjust the top screw so that it will drop from 15 to 20 drops per minute-depending on the size of engine and load. While piston should always be kept well lubricated, too much oil will coat the piston and cylinder head, which will burn as engine gets hot, and cause premature ignition. Too much will also throw blue smoke out of the exhaust. Not enough oil will cause a dry, coughing noise at the open end of the cylinder and later out the piston. It will also make the engine heat up very quickly.

Diagram showing distortion of the piston movement due to angularity of the connecting rod. For clearness of diagram the piston is not shown as its movement is the same as that of the wrist pin.

In the diagram accompanying this article, I have shown the distortion of the piston movement due to the angularity of the connecting rod. It relates to the various angles the connecting rod makes with the cylinder axis during the stroke. Starting at the beginning of the down stroke, the angularity of the rod causes the piston to move more than half of its stroke while the crank is moving the first 90 degrees or quarter of its revolution. The reverse conditions obtain during the return stroke.

It must be understood then that the power delivered from the explosive charge ignited just prior to top dead center is derived from the first degrees of travel of the crank and the piston more or less goes along for the ride for the next 90 degrees.