Old as Dirt!
Join Date: Nov 2008
Location: Tampa Bay Area
Thanked 150 Times in 142 Posts
Rep Power: 9
The raw water system should be protected by zincs. Many heat exchangers have one, mine doesn't. There is a zinc in the transmission where seawater first meets steel. There is one at the other end of the sytem where the seawater goes into the exhaust. I think this makes sense, the exhaust zinc shows some decay. I also think that the water stands there all the time, unless the system is drained. Of course, I could be wrong. But I don't change anything that seems to work.
If it "ain't" broke, don't fix it (of course). We evidently have a slightly different system on a 4-108 which does not have a zinc in the mixing elbow, hence my question. On our engine, unless it's running, there is no water in the mixing elbow although the heat exchanger does, of course, retain some water. N'any case, I'm glad you were able to get things working properly again.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."