Rolly Evans has just sent us another update:
My friend Coburn Benson has let his K sit idle for many years, as the cylinder block had failed along with other problems with the engine.
He allowed me to take all the parts of the engine home so I could do a complete set of CAD drawing. In so doing I became aware of the poor cylinder design compared with the 735 or 740 20 HP engines.
Coburn has two sets of patterns for an existing cylinder, but I would not waste my time with it as designed. He cast two blocks but only one is worth machining. In both the steam ports moved somewhat, but it’s cast iron and just as weak as the original. If it was cast in ductile iron he would have doubled the strength and less likely brake off the rod ears again. I have redesigned a new cylinder with what I think is an improvement and have designed a new box frame for building it wet. I think if I were to build the engine I would modify the packing glands and cylinder heads as well to have 3/16 or 1/4 inch packing.
Not needing it I may not do anything with it as I have been building two 20 HP engines with box frames. Not that I need these engine but it keeps me busy when I’m not working on other projects.
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