Jeremy and Stan:
Thanks for the information. This engine has been in production since 1955. I concur about the ruggedness of the engine. IDUNA's heart beat at idle is 400 rpm. Because the engine has a four-stroke cycle, I assume you only hear the "POP" every other stroke or 200 heart beats a minute. I just received the dimensions of the extra water pump which bolts to the engine. Your current pump, which is smaller, bolts to the "extra pump" to give two pumps. Normally, the extra pump is used to pump sea water and the smaller pump is used for fresh water cooling. The dimensions are 5" high, 7" wide with check valve and 5"out from the engine. It is a neat solution to add another pump to the engine to increase the flow of water through the engine. One may have to add a recirculation loop with valve, to control the water flow when the sea water temperature is cold or I suppose, one could just close the seacock a little, as suggested in the manual when one pump is fitted for sea water cooling. If I have the space, I may install one of these pumps when we depart for warmer waters. The standard sea water pump has a 70 mm diaphragm, whereas the "extra" pump has a 100 mm diaphragm. The respective areas are 37.5 sq cm and 78.5 sq. cm. Based on the area of the diaphragm, the extra pump should pump almost twice as much water as the small sea water cooling pump. The stroke for both pumps is the same. Enough of the engineering talk, let's go sailing.
Fair Winds and Thanks,
Rod, dare I ask the price of this larger pump? And do
I understand that it replaces the existing raw water
pump or is added to it?
Stan Roeder (Waxwing)
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