Well I spent some Christmas holiday time on the boat today, it was around 40 to 45-degrees and inside the motor compartment I had a heater going so it was actually quite pleasant. I was the only one at the marina, so I broke out the beer, turned up the stereo, lit a cigar, and turned a wrench for a while. It was actually quite an enjoyable afternoon. I started late and finished up around 7:00 PM, so I still have a little work to do in order to be able to fire up the motor and see if it sounds any differently than the standard “two hose” installation.
For anyone coming aboard wanting to know why I’m doing this, here are two earlier threads with comments from some other posters. I modified my original idea due to comments received from some posts that made a lot of sense (thanks again).
Here’s what I’m doing. I’m changing out the two hose system to the copper collector system, because I had a rusted out ferrous metal part that finally gave up.
You'll note this diagram is slightly different than the previous plan, and it reduces the number of fittings, and thereby increases the reliability.
All the hoses will be silicone, the collector is copper from a Chris Craft installation taken out of a Hatteras, and the 90-degree bend is a special fiberglass system that was custom run for me (in less than two weeks). The custom run was simply because 4-1/2” outside diameter is an odd size these days, and they didn’t have it in stock.
Here we have the old system off, with part of the new copper system sitting ready. Note the rotted out bottom of the steel collector on the twin hose system, which is the reason for all this aggravation in the first place; too bad, because those are new hoses, and they were a real bear to install two seasons ago. This system uses angled diverters to point the hoses toward the side of the boat.
Here is a close up of the diverter on the original twin hose system.
Here is the riser side of the original installation, and this part remained intact during this change out. The gasket surface was scraped clean prior to mating up the new straight diverter.
Here are a couple of the straight diverters next to the angled diverters. Some differences, but the idea is the same (inject water into the exhaust stream). Although the straight diverters look corroded, and they are, I pecked around with a long neck screwdriver and they’re solid. I removed most of the scale on the inside, and they’re ready for more service.
Here are two gaskets, the one on the right has peen “ported” to allow more water flow, and the one on the right is the stock gasket. In this photo I have not yet taken a long neck screwdriver and chipped out all the scale inside the diverters. I took a cigar and both diverters, a long screwdriver, and a hammer to the parking lot at the marina, and sat there chipping away until these were cleaned up. They look bad, however, there's probably another 20 years left on these guys (in fresh water). In salt water, probably five years.
Here’s why the gasket was ported. It was necessary to open the gasket opening to match the opening in the casting.
Now things are going back together, the silicone “hump hose” is installed with those beautiful clamps, and the copper pipe collector slides right in. Nice !!
I have the fire protection nozzle pointed down and out of the way in this photo, but you get the idea of how the system is going to work. The 90-degree angle is inserted in order to do a test fit, and all is well. The final piece will be another big diameter blue silicone hose (4-1/2” inside diameter, for anyone who may need the data, and the inside diameter of those hump hoses is 3-1/2”)
Here are a couple other cell phone photos, showing detail of the hump hose and the fiberglass 90-degree bend. I'll finish it up tonight, and then we'll be able to make some NOISE under that tin shed marina roof! Interestingly, I was able to put a light beam through the big hose leading aft of the 90-degree bend, and literally "look" into the big cast iron muffler. It looked pretty good, and it's dry from evaporation, so when the big dog barks, it will be with authority!