Valve Lapping Machine

AussieJimG · Sep 13, 2012

Oops, I got so excited at the prospect of another Brian builds... thread that I posted before reading to the end and finding that it is all finished. Must be a record for brevity. Ah well, I still have the popcorn.

Jim

Brian Rupnow · Sep 13, 2012

AussieJimG said:
Oops, I got so excited at the prospect of another Brian builds... thread that I posted before reading to the end and finding that it is all finished. Must be a record for brevity. Ah well, I still have the popcorn.

Jim

Jim---It ain't over till the fat lady (in this case the fat man) sings!!! If I ever get rid of the "real work" that keeps trickling into my design office I'm going to use it on the valves of the Atkinson engine. I have the Atkinson to a point where it will run on its own for about 20 seconds, then it dies out. The compression which felt "good" by rotating the flywheel by hand has fallen off to "not good" so I'm sure thats what is preventing it ftom running as it should.---Brian

Brian Rupnow · Sep 13, 2012

The valve is stabilised and held accurately in position by the portion of valve stem which remains in the valve guide.--Picture it--The valve is in the guide which is in the head. The last 3/8" of valve stem is in the chuck. I am holding the cylinder head in my left hand, exerting a bit of pressure up and away from the chuck. My other hand operates the mechanism. The pressure my left hand exerts determines how hard the face of the valve is held against the valve seat in the cylinder head.

Brian Rupnow · Sep 13, 2012

Well Jeez--I can't believe how good it works!!! For one comfortable swing in one direction with the handle, the valve rotates twice. I have to finish up a bit of "real" work in the morning, and then I will apply some lapping compound and get to work. Its funny---when I lapped the valves the first time while building the engine, I had a nice full ring of "dull" on the mating face of the valve and of the seat. I can't see those rings at all now, but its probably because a certain amount of lube oil got on them and they simply don't show up now.