So, don't be afraid of a tractor engine. They are designed to be tough, and with the exception of not having the salt corrosion problems of boats, a tractor has a far harder life.
I've heard that too. One of the fellows here has the identical motor in his tractor. Running 1700 RPM he uses less than a quart of fuel per hour. And he swears it's dead simple to take care of.
Not sure I would duct straight cooling air into the boat...maybe an air exchanger might work.
Pretty cool if it all works as designed!
I've got blowers but those won't impact the engine room except to evacuate the air.
We need to cool the air exiting the engine. I cannot have a hot muffler in the middle of the bilge. The manifold with separate heat exchanger are designed to cool that temp down enough to make the run (3' forward though probably a 5' length of hose by the time the bend is done) to the water muffler, and then out.
As for the rest of your questions psneeld, I'll have to ask the mechanic. He is closed on Monday.
Out of curiosity, what grade of stainless steel is your heat exchanger made out of?
The heat exchanger is copper as I understand it. It's off an old V8 Mercury.
Why the heat exchanger complexity when a keel cooler cuts the parts count and works fine?
I'm less enamored with keel coolers and like keeping the holes in my boat to a minimum. At present there are three. And too, I do check the depth on occasion with my bottom.
The sad thing is there is a sound the boat makes just prior to touching bottom. And I know that sound.
You are correct, those welds are magnificent. However, I would not have designed the raw water injection point inside the manifold. I know, stainless is very corrosion resistant, but seawater injected into a HOT exhaust stream is even more corrosive at the point of injection than the best stainless can handle. Thats why everyone else makes the "mixer" removeable/replaceable. Also being inside the manifold, a leak will put saltwater into your cooling system. I would build an external mixing elbow, preferably as high as the engine room allows. Insulate "lag" the dry up going side and water cool the down going side. Gerr's fine book has all the info.
Hello Kulas44... Im trying to picture "insulate the lag" as that's what I do have albeit inside the box. You do have a point about stainless and corrosion. As I understand it, corrosion needs air and water and I've definitely got that. Even with something outside the manifold, I'll still have the same situation.
Have you an opinion on how long between failures I should expect? I was told this manifold was "lifetime" and wonder if it's the lifetime of a gerbil (two years) or a grey parrot (60 years) or something else.
Also, theoretically, were salt water to get into the heat exchanger, how would I know? Symptoms? And is that necessarily a bad thing? How bad?
The world we all strive for is ideal. The world I live in has compromises.
This is complicated and I'm only beginning to understand. I appreciate guidance, and thank everyone for their input.