Simon Kelley wrote: > Interesting. Are the compression change-over valves in use? The valves > on my engine were long-ago welded up in high-compression mode to stop > them leaking, but I sometimes worry that the extra strain on the engine > will cause something like this.
For canal cruising I normally leave the change-over valves in high compression. This is because when the engine is doing less than about 1000 rpm, it has a tendency to misfire and blow diesel smoke rings out of the exhaust. On the canal, you are forever slowing down to pass moored boats or working through a lock. Since I have to go down to the engine room to change the compression levers it's all a bit too much of a fag to do it for five minutes cruising. When I am a river where I know I can cruise at higher revs for more than ten minutes I nip down and flick the levers over. > Was this piston replaced at the recent-ish rebuild? Maybe it was a > bad-'un from the start? The pistons were replaced at the rebuild 2500 hours ago. As you say, maybe it was a bad one. I took the piston & con-rod assembly to Peter Thompson (Marine Engine Services) this morning for him to change the piston for a new one. His comment on seeing the old one was that this was definitely one for the black museum. I don't think he's seen a piston in such a state for a long time! I've also left the injectors with a local diesel injector specialist who will check and test them and if needed service them for me. Next task is to dismantle the water pump which I noticed has a leaky seal. Much fun was had yesterday, bow-hauling Arun up to the water point by the lock. For those of you who don't know the area, there is a rather substantial flow of water, presumably from the old mill, directly into and across the cut just upstream from the bridge. There is actually quite a noticeable flow on this section. I managed to get the boat as far as the bridge hole, but then the cross flow prevented me from making any further progress. I tied the bow rope to the support for the pipe bridge while I retrieved several long lengths of rope and tied these to the bow rope so that it ended up about 200ft long. This enabled me to get the rope around a convenient post and, using the additional leverage I now had, haul her forward a foot at a time to clear the bridge hole. All in all it must have taken nearly an hour to move the 250 yards to the water point. Terry Streeter NB Arun - West Hyde
