57. KEYS V


As previously posted, the oil and oil filters have been changed. Nervous about it as a DIY job but it went well. The diesel antifreeze/coolant has now been drained and disposed of. Awaiting delivery of fresh from Cummins. Internet shopping is so nice. The aftercoolers have been taken off and the cores removed.

Each aftercooler is basically 2 parts; a large cast aluminum container and a removable core consisting of many adjacent tubes. An aftercooler removes heat from the compressed air coming from a turbo before it enters an engine’s induction system. The heat runs thru one set of tubes in the core while cooling sea water passes thru adjoining tubes, all under pressure. And after the heat is passed to the water, the now heated water is discharged thru the hull.
Here the impure sea water calcification process has clogged the cooling portion of the core tubes.

No leaks are allowed. The water and hot air must never mix as water introduced into the turbo can be catastrophic. So the parts are soaked in a lot of brake cleaner followed by soapy water and thorough rinsing. The aluminum casting is air pressure tested to be sure it has no leaks of any sort.

The cores of both aftercoolers were pristine as was the starboard alum casting. It was installed new last Feb as part of the boat survey/purchase. The port casting is showing corrosion and pitting with the pitting at the opening being of concern. Can it be ground smooth enough while retaining tolerances to reinsert the core and holding under a pressure test? It is undergoing that shop analysis now.🤞

Also removed from the engines this afternoon were the heat exchangers. They are sent out for cleaning etc much like the aftercoolers. Have not heard a report on those yet.

The heat exchanger is the equivalent of a car radiator. It takes the heat out of the engine coolant and returns the cooled fluid to the engine. In a car, the cooling medium is rushing air, in the boat it is sea water and just like bugs, paper or whatever can make a car radiator inefficient causing the engine to run hot, so too can sea water contaminants, minerals, etc clog the heat exchanger.

So all that sea water going in and out of the boat travels through rubber hoses and those also can get fouled. In addition, the rubber tends to get old, get brittle and or deteriorate. Clamps are subjected to the hot and humid engine room conditions as well. While ALL hoses are dual clamped for safety, a failed hose or broken clamp many miles from land is not good. Some clamps are showing wear and there is black speck evidence on the white engine and floor of some hose deterioration. So new pre formed hoses and marine grade stainless steel clamps were ordered and have arrived. Did I say internet shopping is great?

Also have checked all the belts and replaced those needing replacement, the O rings on the sea strainers and moved one of the bilge pumps to better drain an area of the bilge. Stagnant water is not healthy but also increases steam and humidity in the engine room creating rust. Also coming yet via internet order is matching white Cummins engine paint for touch up. I will have to get someone to adjust the new dripless shaft seal that was installed in May. There is a bit of dripping and the adjustment is in millimeters. I also will need to get a Cummins mechanic to do a valve lash adjustment on the engines (adjusting the clearance usually within a 100th or thousandth of an inch between the rocker arm and valve stem. I’m not an expert on that but I do know what happens if not done

Some might remember our last RV pulled by a small International semi tractor. Coasted into this Memphis church parking lot when the truckIn a split second, explosively stopped running. Delayed valve lash adjustment (I didn’t even know it needed to be done) resulted in the destruction of pistons, engine block head and a depletion to my wallet of almost $12,000. Thankfully the truck, unlike the boat, had only one engine
What the top of a piston looks like when it collides with the head
And what fixing everything looks like. Moral of the story: deferred maintenance is not good


Thankfully, I’m post surgery so can’t do much or any real work other than supervising😎. So I can sit and relax while grilling dinner
and watching for passing fish
Life is hard….

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