Weekend Steam: Who's That Knocking?

The Peerless engine was on the Baker Fan at Pinckneyville in August. Something has a little slack in the engine and is making a pretty good knock.  I was guessing that it was in the crosshead, and you can see one of the engineers go up close for a listen.

Engine noises have always worried me, and I listen for things constantly when an engine is running.  My 1923 Model T had a bad throw on the number three cylinder, and I became skilled at dropping the pan, and adjusting the slack out of the rod bearing.  (Loose Model T rods make a very loud clatter, and you had better stay throttled down so you don't pound the babbit out of the bearing.)  Dad located a good crank and we pulled the engine out of the old truck.  Dad had that engine apart and back together in one day while I was at school, so he would have made a pretty good Model T mechanic.  He taught me to take it easy on machines, and to not be tearing them up through abuse, and I had to be retrained a bit when I was working an oil field job.  I was taking some tools into a cable rig on a muddy lease, and couldn't get the two wheel drive Chevy back to the rig.  The driller took the wheel and told me, "You've got to build a fire in that son of a .....!"  And he did, with the motor revved wide open, mud flying, and smoke boiling off the tires, he got that truck to the back of his rig.  We off-loaded the tools and he drove it back out again, just as loud and wild.  It was a good demonstration, and I always got to the rigs after that, although I don't know how the trucks held together. 

Getting back to the steam engine, the rod bearing on this engine is adjustable, but the crosshead bearing is not.  That is why I think that the crosshead is doing the clicking.  The main bearings on the crankshaft would project a deeper and less definite note.  My guess is that the Peerless is half torn down between shows now, and some newly fitted parts will have it running quietly in October.