Old School Hacker

Piston Rings

There’s a thing with piston rings. When you make them, they start out round. You cut a notch in them with a slitting saw, then put a piece of 1/4″ or so of steel and heat it red hot then let it cool. The idea being that the gap will be pressed closed when it’s in the cylinder. There’s a bit of a problem with this, however. When they go in the cylinder, they are oval. Philip Duclos discussed a way of dealing with this by holding the ring in a clamp with the gap closed and finish machining it. This is a nuisance. The other option is waiting for the rings to seat.

This can be sped up by using something like timesavers. Timesavers is an abrasive that breaks down with time and doesn’t embed. As it wears, it becomes a finer and finer grit. This way it can speed up ring seating without damaging the cylinder. I need to pick some up. I’ve been working the piston back and forth in the No. 1′s cylinder, and you can see how the rings are oval. They’ll seat in time, though. Just need to make sure all the grit(from honing the cylinder) is out of the steam passages.