Re- Cummins 6bta 5.9 270 hp with a Twin Disc gearbox MG-5050SC Hello all. In mid 2017, a friends Twin Disc marine gear 5050SC came close to failing. Fortunately he noticed an oil sheen developing behind his boat. The problem was quickly traced to his Cummins marine gear oil cooler and attended to. As a result of my friends marine gear issue, I removed my Cummins marine gear cooler and replaced it with one (offered by Seaboard Marine) that utilizes two zincs for added internal protection, as opposed to zero zincs in the factory marine gear cooler. ( suggestion- refer to two 2017 Sentoa maintance tips on marine gear coolers) The stock Cummins marine gear oil cooler has a raw water port hose barb on the lower end located close to the rear of the engine block. The PSS dripless water cooling line is attached to this hose barb. This hose connection point is pretty much out sight. I personally dislike below the waterline fittings that I cannot readily see without having to remove stairs and do boat yoga. Since that cooler change out, I replace my zincs at 5 to 6 six month intervals. I also added a fresh water flushing set up a couple of years ago. Even with the fresh water flushing, I have noticed that the the marine gear zincs still showed more degradation than I would have expected. When the engine is running, this water line feeds the PSS dripless shaft . The marine gear cooler and the PSS dripless’s 3/8 inch hose are held in place generally by a single hose clamp.( I use two clamps) The consensus with others that I have spoken with, was that since both the PSS dripless unit and the marine gear oil cooler are below the boats water line , all felt that when the engine is off, salt water can and most likely does flow back up thru the PSS dripless cooling water line and re-enter the marine gear cooler. The salt water then just sits in the marine gear oil cooler, doing what salt water can do to metal. My boat is on the West Coast and is in the water year around. I haul out about around every 3 years and change out the PSS dripless at every other haul out, which includes the dripless cooling hose and clamps. But the fact remains that the marine gear cooler line connection point is still out of easy sight for long periods of time. Some months ago, I learned that Seaboard Marine, offered a kit called - Cummins Heat Exchanger End Cap Kit with Raw Water Port. I bought the kit. To install the new cap, I drained my engine coolant, then removed the various HE hoses and then unbolted the heat exchanger. I installed the new end cap and a 90 degree elbow hose barb fitting. After reinstalling the heat exchanger and refilling the coolant, I relocated the marine gears water cooling line to the newly installed end cap hose barb located at the aft end of my heat exchanger and tighten the clamp. I then removed the marine gears water lines hose barb fitting and replaced it with a solid plug. The HE cooling hose new location is well above the boats waterline. This left the PSS dripless cooling line and fitting at the shaft below the water line but at least that it is in a regularly inspected location. The marine gear cooling water lines new starting point on the heat exchanger solved at least two personal design issues, one of which, it eliminated one below the water line potential failure points, which I think is a win. Also the previous connection point that was not in an easily seen location, is now at the new connection point is plainly visible , which I felt was another win. I checked the marine gears zincs after three months and found a minimum of wearing away, so a minor third win. I have a couple pictures if anyone is interested. Robert Claycomb M/v Deneige 32-276

Robert Am interested in pictures, nice write up and seems a great solution 37-116 Fhschmidtke@gmail.com Sent from my iPad Rick Schmidtke > On Mar 13, 2022, at 9:20 PM, Robert Claycomb via Sentoa <sentoa@lists.sentoa.org> wrote: > >  >  > Re- Cummins 6bta 5.9 270 hp with a Twin Disc gearbox MG-5050SC > > Hello all. > > In mid 2017, a friends Twin Disc marine gear 5050SC came close to failing. Fortunately he noticed an oil sheen developing behind his boat. The problem was quickly traced to his Cummins marine gear oil cooler and attended to. > > As a result of my friends marine gear issue, I removed my Cummins marine gear cooler and replaced it with one (offered by Seaboard Marine) that utilizes two zincs for added internal protection, as opposed to zero zincs in the factory marine gear cooler. > ( suggestion- refer to two 2017 Sentoa maintance tips on marine gear coolers) > > The stock Cummins marine gear oil cooler has a raw water port hose barb on the lower end located close to the rear of the engine block. The PSS dripless water cooling line is attached to this hose barb. This hose connection point is pretty much out sight. I personally dislike below the waterline fittings that I cannot readily see without having to remove stairs and do boat yoga. > > Since that cooler change out, I replace my zincs at 5 to 6 six month intervals. I also added a fresh water flushing set up a couple of years ago. Even with the fresh water flushing, I have noticed that the the marine gear zincs still showed more degradation than I would have expected. > > When the engine is running, this water line feeds the PSS dripless shaft . The marine gear cooler and the PSS dripless’s 3/8 inch hose are held in place generally by a single hose clamp.( I use two clamps) > > The consensus with others that I have spoken with, was that since both the PSS dripless unit and the marine gear oil cooler are below the boats water line , all felt that when the engine is off, salt water can and most likely does flow back up thru the PSS dripless cooling water line and re-enter the marine gear cooler. The salt water then just sits in the marine gear oil cooler, doing what salt water can do to metal. > > My boat is on the West Coast and is in the water year around. I haul out about around every 3 years and change out the PSS dripless at every other haul out, which includes the dripless cooling hose and clamps. But the fact remains that the marine gear cooler line connection point is still out of easy sight for long periods of time. > > Some months ago, I learned that Seaboard Marine, offered a kit called - Cummins Heat Exchanger End Cap Kit with Raw Water Port. I bought the kit. > > To install the new cap, I drained my engine coolant, then removed the various HE hoses and then unbolted the heat exchanger. I installed the new end cap and a 90 degree elbow hose barb fitting. After reinstalling the heat exchanger and refilling the coolant, I relocated the marine gears water cooling line to the newly installed end cap hose barb located at the aft end of my heat exchanger and tighten the clamp. I then removed the marine gears water lines hose barb fitting and replaced it with a solid plug. > > The HE cooling hose new location is well above the boats waterline. This left the PSS dripless cooling line and fitting at the shaft below the water line but at least that it is in a regularly inspected location. > > The marine gear cooling water lines new starting point on the heat exchanger solved at least two personal design issues, one of which, it eliminated one below the water line potential failure points, which I think is a win. Also the previous connection point that was not in an easily seen location, is now at the new connection point is plainly visible , which I felt was another win. I checked the marine gears zincs after three months and found a minimum of wearing away, so a minor third win. > > I have a couple pictures if anyone is interested. > > Robert Claycomb > M/v Deneige > 32-276 > > > > > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org