I assumed the price listed by Bill Mill, Sabb America, was only for the "extra pump" and not the two pumps combined. I will confirm the price quote. The more I study the diagram, the more I believe a plate could be used to cover the opening between the "big" pump and "small" pump. The other approach is to cut out the center of the small diaphragm and let the "small" pump serve as the "blinding" plate. It would be necessary to add a cover plate where the check valve assemble is fitted on the "small" pump. and cap the discharge port With this approach, the two drain petcocks on the "small" pump are still available to drain the cooling water from the engine. I believe either approach is a practical means to increase the flow of cooling water through the engine yet maintain the reliability of the diaphragm pump and still be able to run the engine between 3 and 4 minutes without cooling water on initial startup.
John Churchill, BCC Bucephalus, just left Baltimore's Inner Harbor about 1 hour ago - destination, Norfolk, VA. He is on his return trip home after spending two months in Maine. Bucephalus was a pretty sight beating out of the harbor in 10 knots of wind with white sails framed by a blue sky and a historic Chesapeake Bay city. I had an opportunity to visit Bucephalus then have dinner with John and other mutual cruising friends yesterday. His BCC is both beautiful and functional - a well founded vessel.