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post #6 of Old 08-12-2009
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Westerbeke failures

A number of Westerbeke engines failed because of the very high exhaust backpressure, diversion of coolant from cylinders 3 and 4 for the water heater, high thermostat, etc. I measured my backpressure at a ridiculous 10 to 12 psi at 2,000 rpm, and the head was running about 100 degrees hotter at cylinder 4 than cylinder 1. After the mods the backpressure was down to around 4 psi. Still a little high but liveable. There's not a diesel engine in the world which would last that long at 12 psi, so don't blame Westerbeke for the engine problems.

The data was never released, but I think Westerbeke replaced something like 75 motors, with as many as 5 on one boat, until they figured our what the problem was. I don't think they they will let any boat manufacturer install these things again without checking what they intend to do with them.

As I told Everett privately - the normal failure was in cylinders 3 and 4, with compression down to 100 psi or so in them, while cylinders 1 and 2 were still up in the 500+ psi range. The inability to scavange the exhaust from the cylinders closest to the exhaust manifiold coupled with the hotter temperatures in them caused carbon fouling on the rings and walls, eventually damaging the rings which in turn scored the cylinder walls. This normally started to happen at around 300 hours, maybe less if you spent hours motoring. Someone who uses the motor for 5 minutes to get out of his dock would never see a problem - the engine does not get hot enough to start the damage. The boat which got 5 engines lost every one during 3 round trips down and up the ICW. They motored maybe 8 hours a day for weeks at a time. Only made it thru once and even then the engine had to be replaced in the Bahamas. Another boat lost 3 or 4 engines in the ICW.

The C400 Association did a number of things to get the owners to test for these problems. We did several newsletters that we mailed to them. We bought compression and backpressure gauges that we loaned out. I'd guess that maybe half of the owners did not check for any potential damage, and perhaps 2/3 or those who did wound up with a new engine. They had absoutely no idea what was in store for them in the future. The only way to find out was to do a compression test. The damage occurred so slowly that it was almost impossible to notice the power loss, until the engine eventually becomes unmanageable.

Ron Marcuse C400 #74 'Good Vibrations" - gone but not forgotten

Ron Marcuse
Telstar 28 #359 "Tri-Power"

Last edited by captron400; 08-13-2009 at 05:43 AM.
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