Capn Craig
Guru
- Joined
- Oct 16, 2010
- Messages
- 519
One of the things I had to remove to gain access to my strut backing boards was the gen set (7.7 KW diesel Westerbeke 1800 rpm 3 cyl.) muffler. It had an Onan steel waterlift muffler. As I don't think my boat has ever been in salt water, it was in good shape. But I plan to have it in salt water long before I am willing to revisit the muffler, so I plan to convert it to fiberglass or? The old Onan is about 15" in hgt and diameter. The gen set has a 2" od exhaust elbow that exits about a foot above the waterline. The muffler has about a foot tall riser pipe coming out the top. This is about 10" higher than the exhaust elbow. The rubber exhaust hose then runs down hill to exit the transom about 6" above the water. The exhaust line from the muffler back to the bronze thru hull is 1 1/2". My Westerbeke manual doesn't say much about exhaust size. The Centec Vernalift web site says I should have a 2" exhaust before and after the muffler. There chart says 1 1/2" is adequate for 10HP. 2" should be used up to 30HP. There is a big difference between 10HP and 30HP. They make no adjustments for RPM. My 1 1/2" exhaust seemed to work just fine.
I see that Verna Lift's come in several heights and diameters. Any difference in performance or noise? Is this a good choice? What is quietest? With the layout I had, the high point after the muffler is 10" higher than the exhaust elbow, do I run the risk of flooding the engine if I crank it excessively and it doesn't start? Is the 2" diamter exhaust important enough to change out the 1 1/2" bronze thru transon port.
So many questions.
I see that Verna Lift's come in several heights and diameters. Any difference in performance or noise? Is this a good choice? What is quietest? With the layout I had, the high point after the muffler is 10" higher than the exhaust elbow, do I run the risk of flooding the engine if I crank it excessively and it doesn't start? Is the 2" diamter exhaust important enough to change out the 1 1/2" bronze thru transon port.
So many questions.