Gary Nau’s Hill 2R 10 KW generator set is of unknown age and lineage. Based on serial number and other details, we think the engine is mid to late ‘40s. As a generator set, it doesn’t appear to be the type sold by Hill, nor does it appear to be of a military origin. It mounts a Century generator, while Hill commonly used GE units. Most likely, the engine was purchased as a power unit and converted by an outside vendor. The 2R engine was rated for a maximum of 23 horsepower at 1800 rpm, but this generator produces 60 cycles at 1200 rpm and at that speed, the engine was rated for 18 horses max and 13.5 continuous. Doesn’t seem like a lot but look at the nearby torque graph and note that 82 lbs-ft of maximum torque (60 lbs-ft continuous). At 1200 rpm at the continuous duty power level, the engine used about 0.85 gallons per hour.