New engines: small, quiet, clean, efficient

This week (November 2013) we went for our first cruise aboard Seven Bells with its new engines installed! The Christmas lights on Lake Union were lovely, and the engines were so quiet I found it hard to believe they were actually running!

Take a look at this album of photos taken by Jenny, one of my guests aboard the boat on Monday night.

The new engines are 4-cylinder 53hp Yanmar 4JH5E engines, purchased from MER Equipment in Seattle and installed by CSR Marine. The entire process of repowering Seven Bells took over three months to complete. The first stage involved extensive research to determine which engines (and transmissions) would best meet the needs of the boat (the old transmissions would not fit to the new engines). This was a complicated matter because I wanted to find strong and reliable engines that generated plenty of torque to push the boat somewhat past its hull speed of 8 knots and up to 10 or 11 knots at full throttle. But I also wanted enough horsepower to cruise all day at 7 knots while only running the engines at half their capacity. In the end, I decided on the Yanmars because they matched the 55 horses of my previous old Chrysler-Nissan engines, had a power curve virtually identical to the old engines, had an excellent reputation among other boat owners, were cheaper than engines from alternative manufacturers by a few thousand dollars, and were readily available.

The installation of the engines by CSR Marine was a major undertaking -- much more challenging than replacing an engine in a car or truck. First, the boat had to be hauled out of the water in order to remove the old engines. Then we thoroughly cleaned the bilge, removing gallons of sludge, engine oil, and coolant deposited there as the old engines went through their process of final failure. The new engines finally arrived and were placed in the boat, which was once again dropped into the water and moved into a covered floating shed for protection from the elements. Whereupon we discoved, to our collective sorrow, that the new transmissions delivered with the engines were not designed to accomodate a twin-screw boat such as Seven Bells. It took  a couple more weeks to get the correct (and more expensive) transmissions delivered by MER Equipment. In the meatime, the folks at CSR rebuilt the fore-and-aft timbers in the engine compartment so they would be ready to receive the engine mounts and we could install the engines.

The actual installation process took several days, including a lot of custom work to ensure the engines were able to connect properly to the propellor shafts while securing the engines in the best location in their compartment.  Meanwhile, we needed to make sure that the pitch of the propellor blades was properly adjusted to accomodate the new engines, which ran at a slightly higher RPM than the old engines. We also had some concern that the propellor shafts were themselves too massive to be easily turned by the new (and relatively small) engines. In addition, the new engines came packaged with new  instrument/ignition panels, with readouts for RPM, temp, and oil pressure.

On December 14th, James Life and Paul Life, the brothers who work at CSR, fired up the engines and took the boat for a test cruise. The boat with its new engines ran well beyond our hopes. The 53 hp engines had plenty of power, and the propellors appeared to have been adjusted to perfectly complement the power output of the engines.  This meant that the boat could remain in the water with no further concerns about the engines, the propellors, or the propellor shafts. In the wake of the test run, the most important recommendation from James and Paul was that we invest a few hundred more dollars to install new vertically configured mufflers, which would make the engines both quieter and safer (by making it impossible for the raw cooling water expelled from the rear of the boat to ever back up inside the engine compartment, thus potentially sinking the boat). 

Finally on December 16th, with the help of my friends Cambrea, Stephen, Randy, and Keith, I went to CSR in Ballard to pick up the boat and drive it back to its slip at Seattle Marina at the north end of Lake Union. Everything worked well, and the new engines were miraculously quiet compared with the old ones. 

In the next couple of weeks I will undertake a final cleansing of the bilge in the engine compartment. Then I will finish painting the engine compartment with some nice, fresh, bright, white paint. Anyone want to help?