Posted: Mon Jun 16, 2008 8:00 pmAny pointers at this direction? I'm thinking about using a rotating pump housing and a load cell to measure torque. Mostly for inline and flat 4 engines NA below 300bhp.
It should work, only problems might be cooling the oil. The temperature rise of oil will be very roughly double that of water, and where hot water can just be dumped, you need to cool and recover all that hot oil.
Only other complication I am aware of, might be reaction forces from the flexible hydraulic hoses. These will likely be running at very high oil pressure, and the hoses themselves will generate forces that may influence the measured torque reaction of the pump. There are ways around this, but recognizing the problem in the first place is half the battle.
If you already have a hydraulic pump, it is probably worth a try. If not, a suitably large and robust pump will certainly not come cheap.
I have seen this idea used successfully testing smaller outboard motors, and smaller air cooled engines, but never at anything like 300 Hp.