Water pump impellers, such as those on the engine or genset, are typically reliable. But they do wear, and old age takes its toll. We recently dug up a pdf file on inspection which is quite interesting.
To download this pdf click here.
Posted by Steve Dashew (May 20, 2011)
May 20th, 2011 at 6:37 pm
Steve,
With much due respect, why are you still going down this road. Metal boats are begging to be built with skin coolers and dry exhaust that are sooo much better. No below the waterline thru-hulls (with the exception of an above the WL intake at a sea chest for the watermaker and washdown), plugged intakes, sea strainers, raw water pumps with troublesome impellors, heat exchangers with problematic zincs, ditto for gear cooling. Even forget the the “marinized” (= problematic) engine, elbows, manifolds etc.
much appreciate your contributions, fellow boat builder
John Crowley
WHL Shipyard
May 20th, 2011 at 7:19 pm
Hi John:
We do use hull coolers for air conditioning, fridges, and hydraulic oil. However, dry exhaust systems are, in our opinion, just as complex in their own way as wet systems. In addition they are noisier, dirty, have a variety of maintenance headaches, amongst other issues. The trade off is the raw water pump and its impeller. If there is enough space to work, changing the impeller is not a big deal.