...or... "Chowderhead Makes Mayonnaise"
Chowderhead is a 1965 38' SF and she was repowered years ago with tiny little DD 4-53 Naturals.
Ginger, my port engine blew a hose clamp on the lower coolant hose last season and ran dry until the paint on the exhaust manifold started to smoke. I was in the process of getting my gauges sorted at the time and the smoke was the first (and last) indication.
I changed the oil a couple of times, fixed the coolant hose, new exhaust manifold tips, refilled with FleetGuard and distilled water and she ran like a champ the rest of the season.
Blackstone Labs said they detected elevated levels of coolant in the oil on this year's annual oil report and suggested keeping a close eye so I knew something was up.
Fast forward to shake down day when steam started to blow out the port exhaust at 1000 RPM. Limped back to the dock on the other engine and found water on the dipstick and mayo under the valve cover.
There are those who suggest it might just be an oil cooler failure but that would be oil in the water, not water in the oil as I understand it.
My DD mechanic won't be part of anything less than a $10K overhaul of a 40 year old, too-small-for-the-boat engine and that doesn't seem to agree with the $200 I have available for this project :)
Necessity being the mother of invention and all, I'm a software engineer who's becoming a diesel mechanic. My plan is to read the manual very carefully, buy a set of head gaskets for $80 and see what I can break. Worst case; I'll still have a broken engine, best; I'll save it.
Calling on the power of the forum for tips and advice.
You can get every part on the engine through diesel pro once you give them the part number. Call them on the phone instead of just looking on the website they will track stuff down for you. If you have a service manual and parts book you can get the number. I just rebuilt my starboard engine and every part was available.