Adjusted engine valves

I knew it had been a while since I adjusted the valves on Aeolus and I had started to notice some unusual knocking and pinging. Adjusting valves is both fun and easy, and I launched into it today. It was a bit rainy and though there was some good wind, I chose to maintain rather than sail. The boys read books and played with figurines while I was sprawled around the diesel. Overall the valves were in decent shape, with some not needing any adjustment at all and several needing minor corrections.

This photo shows the identical parts of a Universal diesel, though it isn't one.



(For anyone not familiar with the purpose of the gap adjustment for valves, it is as simple as understanding that air and fuel need to be let into the cylinder chamber and then exhaust let out. The valves open and close to do these things and need to open and fully close at precisely the right times. Adjusting the valves allows you to make certain that they are not too tight, and thus preventing the valve from closing and sealing all the way, or too loose and knocking a lot and opening too late or too little. Remembering that these valves open and close once for every engine rotation at a speed of 2,000 RPM or more than 30 cycles per second is enough to convey the importance of proper timing.)

Valves on a Universal 5432 or M40 are set to between .007 and .009 inches. Naturally, I used .008. There were several valves that were loose to a gap of .012. Valves almost always become looser with time because the surfaces that are rubbing and pounding are wearing away.

When I put her all back together and fired her up, Voila! Quieter and the knocking and pinging gone. Turns out that .003 of an inch is enough to cause some noise. Another reminder of the way all good mechanics develop a fine ear for the motors they maintain.