On the subject of cylinders. I've asked this many times and can never get an answer. I'll ask here. What are the two round plates that have sort of a spoke shape to them. They are located just above the cylinder valve, center of it on both sides. I've seen photos where there is a tad bit of steam coming from them. This is on most Pennsy engines and are on the K4 cylinders as above.
KTB.