Had a scary moment in the engine rebuild yesterday when after hooking up the temporary cooling system (a bucket filled with water and some garden hoses) water started spraying from the exhaust! Shut the engine down and when in the house to have dinner. Later that night I realized that the zinc bung just below the exhaust had been leaking and the exhaust manifold wasn't on tight. It was creating a venturi effect and sucking in the water spray from the bung and pulsing it out with the exhaust. Today I tightened the manifold and the problem resolved.

I then descaled the engine with 7-10% HCL (muriatic acid from the hardware store) circulated through for 5 minutes, followed up with baking soda and water to neutralize the acid then about 5 gallons of clean water that I allowed to circulate through the system for 5-10 minutes. All told the engine was running for about 25-30 minutes. I might catch some flack for using HCL for the descale and I wouldn't recommend it for routine maintenance but I decided to go for it after testing a few bronze (brass perhaps given the anodes?) parts from the engine in undiluted HCL (~30%) for 5 minutes. They did fine but were totally descaled. Also this engine is all cast iron - no aluminum heads or any other part and I removed the two zincs to prevent them from being eaten. Lastly the engine had a bunch of fine sand in the bottom of the water jacket that was sort of encased in scale. The only way I could see to get it out was to bust all that scale first then flush it out. Seems to have worked.

I then drained the oil from both the engine and transmission. The engine oil was great but after the 30 minutes of running the transmission oil looked like thin mayonnaise . I'm hoping it's from condensation that built up over the years this motor sat and not from something I have yet to discover. We'll see when I give it a flush then refill with new oil and run it again.

Next is to take care of a few oil leaks, replace all the rubber hoses, new thermostat, raw water impeller, degrease the thing and slap some paint on. Then on to the interior of the boat - new rear engine mounts, paint for the whole engine "room" and a drip pan of some sort for under the motor to keep everything out of the bilge.

What have others done for a drip pan under the engine? I've got a bunch of 20oz copper left over from a recent job and I'm thinking of making a simple soldered copper pan that laps onto the logs the engine is mounted on then hangs down under the oil sump - with a pretty agressive slope forward so I can mop up the inevitable spills easily. I also have some galvanized sheet from another job that solders nicely and it would take paint better than the copper. Anyway just spitballing now... if anyone has a recommendation let me know.

-Ben