Yep, it's a piston out of a Ingersol Rand KVS 26CT Engine. This one was over limits on out of round and was pulled. The bare piston weighs 400lbs so it makes a nice solid vice stand.
Here's a few pics.
The piston has two threaded holes in the dome of the piston that are used for attaching a pulling tool to remove the piston from the engine. I just cut a piece of plate and drilled two holes so I could attach the plate to the piston with bolts....worked great.
This is the KVS 26 engine, it's rated at 1000 HP at 330 RPM and drives two integral double acting compressors. This engine is used to compress natural gas on a pipeline and is the smallest engine/compressor on the pipeline.
Inside the KVS crank case taking crank thrust readings. The power rods are removed in this pic so the power pin is wrapped in cardboard to keep it from getting scratched.
Here's a few pics of one of the larger units, It's a Clark 12 Cyl two cycle engine driving three double acting compressors, it's rated at 4500 HP at 300 RPM.
I have more pictures of the Clark here: http://www.advrider.com/forums/showt...ight=hodakaguy