Sorry, but I don't know where your getting the idea running a hyd gen from the M.E. would be inefficient. It now costs me about $1000/day in fuel...
Years ago one of the major megayacht shore power converter companies was talking about building something like this. It was basically designed for...
I don't have tach's on my Cummins, lol. Mine are gensets, only ECU's, electronic governors, and frequency meters on swbd. :D
On my Cummins 6BT's I've got something a little different. I've got magnetic senser drilled thru and mounted in the bellhousing area, it counts...