We have now completed our 3 week trip to Desolation Sound on the new engine and systems. All went well and we are at 80 hours on the new engine. Some observations:
- Folks that know our boat tell me that the reman lehman is quieter overall than our old engine. After all my effort on this project, I was having a hard time believing this was the case. It was nice to have this confirmed.
- The boat runs much smoother now, not all due to the new engine but probably a combination of the new engine, new mounts, rebuilt transmission and the additional pillow block we installed on the prop shaft ahead of the PSS.
- The engine starts almost instantaneously with very little cranking. Our old engine needed considerably more cranking, especially when cold.
- I run about 300rpm less for the same cruise speed.
- Initially I was a little disappointed that the new engine was putting a visible slick out the exhaust. This got slowly better as we ran the engine, and right around the 50 hour mark things seemed to settle in and now we only get a very light slick at cold start.
- Exhaust smoke is greatly reduced. It is a little heavier when cold, but then it diminishes and is very light through all rpm levels.
- Our old engine, in our last season with it, used about a liter of oil for every 10 hours of running. Some just oozed out of various areas on the engine, some definitely went out the exhaust. The new engine had an initial oil change at the 15 hour mark, and I have observed little to no oil useage in the 60 odd hours I have run it since.
On our summer cruise this year some friends of ours who are considering moving to a trawler decided to charter a CHB 34 to see if they could make the switch. That trawler of course had a Ford Lehman identical to ours in it. Although our boat is bigger and weighs considerably more, it was a great chance to see the difference. It was night and day. Of course I believe that poor Lehman in the charter boat was not living an easy life.....
We did have some challenges, of course:
- It is difficult to find marine mechanics that can diagnose and actually repair an engine. I went through two local mechanics before I found one that was able to work with me and didn't immediately want to start "black box" repairs (ie. just start replacing things). My local mechanic, combined with the knowledge and support from Industrial Engines was a great combination. My word of advice for anyone - make sure you educate yourself on the engine installed in your boat so that you can evaluate the advice you are given. Use a combination of information sources, but realize that you will often be given conflicting advice and ultimately it is up to you. The internet can be a valuable source of collected knowledge, but it can also be brutal. If I was looking for more things to keep me up at night, all I have to do is start reading forums!
- During our initial sea trials we monitored the engine using temperature guns and saw a trend towards excessive heat buildup around the #5 and #6 cylinders. After some analysis it was determined that the water heater loop, which was set up as per "factory", was in fact allowing too much flow to bypass. Apparently our water heater has a much higher flow rate with larger passages and this was the root cause. We bypassed the heater and the problem went away. For this season we used our generator to make hot water, and have a plan to install a heat exchanger to recover heat from the engine oil for next season. This keeps all systems separate.
- Air leaks in the fuel system dogged us for a while. The symptom we observed was a complete shut down of the engine approximately every 2-3 hours of running. It fired right back up, but it was a bit nerve wracking. The entire fuel system back to the tanks was replaced, with a new distribution manifold and all new fuel filters and valves. It turned out I was focused on the wrong part of the fuel system. The culprit was the fitting on the inlet side of the engine mounted fuel pump - the shoulder of the fitting bottomed out before the flare did. I discovered it by turning on my electric backup/priming pump and leaving the system pressurized over a weekend - visible fuel appeared and I was able to trace it. I managed to find fittings that fit properly, and once done the engine has run flawlessly since then.
- Our oil pressure sending unit failed and became erratic after about five hours of running on our trip. No problem, I have a mechanical guage in the engine room that confirmed all was ok. I also had a spare sending unit, which I installed at anchor. It too failed after about 5 hours of running, in the same way. I have since ordered a different, more substantial brand of sending unit at the advice of my mechanic. Hopefully it will last longer.
Overall the project was a success and we are very happy with the end results. Industrial Engines in Vancouver gave us exceptional support through this project. Judging by my last trip to their shop, where I observed no less than 5 Lehmans in various states of rebuilding (some from commercial boats, most from pleasure) I would say that there remain a considerable number of Lehmans in service! I am happy that I moved away from my original plan to replace the Lehman with a more modern engine. The effort and expense would have been an order of magnitude higher.