Almost all of these engines run a straight 40 weight, low sulfated ash, low detergent (blowby isn't really much of a consideration as there is no liquid fuel and minumum carbon/acids) and it tends to reach the end of its life by thickening out of grade, as there are multiple absolute (stainless steel) bypass filters as well as full flow filters mounted on them, and oil capacities in the system are as much as 110 gallons. The oils are now down to as little as 0.51% sulfated ash to protect the catalytic converters mounted on many of these engines.
As most users of this hardware buy oils in big volumes (5000 gallons at a time in many cases) they get a very strong technical services package from the oil provider. Petro-Canada and Imperial Oil are the two biggest competitors in the Canadian market, with Petro-Canada having stremely well regarded group III based products in these applications.
They run steady state RPMs in the 900 to 1800 rpm range, and the highest horsepower unit I personally dealt with was a Waukesha 7042GL putting out around 1400 horsepower.
Used oil analysis is everything when it comes to these engines as much for diagnostics as oil change intervals. Glycol contamination and bearing wear are two big ones that come to mind.
Carbon in these engines is a big issue, especially as I have seen situations where accumulated carbon in an engine not running well broke off, stuck in a valve seat and caused the valve stem to break, bouncing the valve around inside the cylinder until it was a kidney shaped, rounded piece of metal that ended up used as a paper weight by the mechanic. After what was probably only a few seconds, the shaking became severe enough for the vibration sensor to automatically shut the engine down.
This summer I was working for a natural gas mid-stream company with a whole bunch of compressors, and my dad has been a lead operator for almost 30 years in the field with them. I usually ended up working with the mechanics on whatever he was involved in.
