12v71 Detroit electrics

Yes, you could change the starters and alternators to 24 volts fairly easily and cheaply. The next question is the biggie.... I would take the airbox inspection ports off and shoot light oil in there and turn them over by hand to circulate it and lubricate it. You can only rotate the engine the same way it turns normally or you'll snap the water pump shaft off.

To Capt J's advice I'll add a BIG warning when you bar them over to make sure the stop solenoid (which also needs changing to 24V) is engaged! If they have good compression there's a possibility they will start, with a big breaker bar on the crankshaft nut that can get ugly in a hurry!

You could also yank the emergency shutdown flaps on the air intake and don't need electric for that.

Not remove them. When you pull the release on them, it closes off the air intakes on the motor and the motors will not allow enough air into the motor to run.

Neither the raw water pump, nor the fresh water pump, not their respective shaft and internal components will be harmed in the least by rotating the engine in either direction.

If barring the engine over via the bolt which secures the torsional damper to the nose of the crankshaft, an engine the size of a 12V-71 has sufficient internal friction that the bolt can potentially be loosened by attempting to rotate the engine in a counterclockwise direction, as viewed by a person standing in front of the engine and facing aft. This can be catastrophic later when the engine is running, potentially allowing for detachment of the torsional damper and consequential damage to engine and boat, as well as to any person(s) in the vicinity.

Thoroughly understand what you are doing before you do it, or have a competent professional involved.

Ron Sparks

Hello Ralph: Thank you for your comments.

Why are you changing from 32 volt?
I have 32 volt, 24v, and 12 volts on my boat and see absolutely no reason to change the alternators or other 32 v items.
Most bilge pumps handle all the above. Get a spare 32 v Alternator if you are heading on a long journey, other than that, why go to the cost and effort to change?

I'm sure you have had all your questions answered by now. But I'll throw in a couple of penny's here. The 71's are simply one of the best engines DD ever built. I swear they will run on sea water. Just kidding! I have 12v71's and they have never let me down. As for your 32V change over. Yes the starters and alternators are simple enough to convert and as mentioned you'll also have to change the battery chargers. But the real rub is that the entire vessel is on a 32v system. IE battery powered lights, pumps and so on. A change over can get involved and expensive. Just food for thought.

Yes they do. No computers, fuel injection pumps or complex tuning set up. And contrary to popular belief they are economic and when well maintained they don't smoke.