The NEW GM engine Hydraulic Power Unit - 20,000hrs+?

[popeye]

I have never quite understood why the small and big block gas engines in the "oil patch", configured as 40 to 100hp hydraulic power units primarliy for PC pump applications, had such a short life span until recently. In the majority of cases the operating time between MOH is less than 10,000hrs with the primary failure being the exhaust valves and seats. After some scrutiny we have found the cause to be running the engines on natural gas and propane, summer and winter respectively, without adjusting the timing or carburation of the engine to "match" the type of fuel being used. Set up to run on natural and/or casing gas will, in most cases, cause pre-ignition on propane. The result burnt valves and seats.
GM now offers closed loop fuel systems versus open that eliminates this problem. As well as, fuel delivery systems that at a flick of a switch makes the appropriate adjusments to operate at its maximum efficientcy no matter which fuel is being consumed. devans@cefranklin.com for more