Evening all.

In my workshop I have a Lister 4 cylinder diesel, air cooled 3 phase Alternator I think it must only have two poles as to get 50 Hz it seems to run far too fast and makes far too much noise in so doing.

It is at least twice as powerful as I would ever need and I often use it at about half revs at which speed it still generates enough to run an old Milling machine, However It would be very nice it I could run the diesel at this low speed and still get 50 c/s and the correct voltages. It is skid mounted, bolted to the floor on a heavy chassis but the engine and alt. are close coupled. I was toying with the idea of separating them and hooking up a chain shaft drive behind the set to gear the motor speed down by at least half.

This will be a big job I fear, as they are very close together and it might be necessary to move the engine to the right a bit to enable sprockets or even pulleys to be connected to gear down the alternator. Has anyone ever done this and has anyone any simpler lateral solution.

Or - alternately does anyone wish to swap a noisy 40 Kw set for a nice quiet 15- 20 Kw set ?