Electrolysis Question

[Whidden]

My wood power boat was built with a straight six motor which at some point was repowered with a short block v8. The v8 obviously takes up more space and the bottom of the motor sits so close to the bottom of the bilge that a portion of it sits in bilge water. She's a pretty dry boat but that spot is also one of the lowest spots in the bilge.

Should I have electrolysis concerns?

[nedL]

The back end of the engine is already common (electrically speaking) with the water throught the prop shaft, so I believe having the oil pan touching bilge water won't do anything additional. (If is is a sheet metal oil pan you should keep an eye on it so that it doesn't rust through from normal rust.)

[Gary E]

I would not worry to much about anything other than RUST. If the oil pan is steel it may rust through and the oil will leak into the bilge, if the pan is cast iron it will just take longer to do the very same thing. To insure that does not happen I would be hoisting that engine up so that a compete cleaning with wire brushes and sandpaper is easy, and then I would paint it with Rustoleum, the more coats you apply the longer it will last.

Edit
To me this falls into the... "pay now using preventative measures, or pay a LOT MORE LATER because the engine oil ran out and you now need a rebuild or a new engine."

[ 12-24-2004, 03:16 PM: Message edited by: Gary E ]

[cbob]

Ned, the connection between the engone and shaft through reverse gear is not a sure thing, due to oil film and other considerations, which is why bonding and grounding systems use a sort of spring loaded bronze brush riding on the shaft, when stopped or turning, to guarantee an electrical bond. Don't know where these are available now, but a good marine electrical outfit should.
That said, RUST is the real problem. As the oil starts to leak out, at some lower crankcase level the oil pressure will drop due to loss of oil pump suction. The low oil pressure alarm (idiot horn) will sound at which time engine shutting down should be done immediatly, as it is about to happen with expensive results quite soon, anyway. Low pressure/high temperature alarms are the cheapest insurance available, don't leave the dock without them. cbob