"I have two circulating pumps
"I have two circulating pumps sitting on my work bench both brand new for my 5.7L 315hp vortex roller motor, DuoProp I/O that I rebuilt in my 97 258 Vista Four Winns. I do not know which of the two pumps I should use.??? One is a Sierra 18-3583 that is the all in one replacement for Volvo and Merc 350 engines. The 2nd pump is stamped MPR made I think in the East somewhere, ALSO NEW... THE MRP brand IS THE PUMP that was on the motor that I TOOK OFF originally. Here's my issue, the new Sierra has a built in restriction from the factory on the 5/8 inch input side and the output or larger port that goes to my heat exchanger, the inside opening is narrower on the Sierra than the MRP. MRP has a wide open 5/8th hole into the pump, no restriction and the housing inside the pump to the large 1 1/2 inch hose is larger than the Sierra pump, so the MRP at least looks like it will flow or push more water. SO WHICH PUMP WOULD U USE THE ONE WITH THE RESTRICTION IN THE INPUT (OR THE MRP) WHICH LOOKS LIKE IT FLOWS MORE WATER. Both pumps have brass impellars that are exactly the same size or same impeller. This is weird to me I can not find any one that knows why these two pumps are designed differently, but both companies say they both are replacements, could the Sierra even though it looks like less water will SQUEEZ thru it help in keeping itself PRIMED at idle better over MRP. If so maybethat is the way to go or is the MRP just a higher volume pump that I should use|||? Sure wou}}ld appreciate a comment of any Kind Thank you in advance Bob"
"I have two circulating pumps sitting on my work bench both brand new for my 5.7L 315hp vortex roller motor, DuoProp I/O that I rebuilt in my 97 258 Vista Four Winns. I do not know which of the two pumps I should use.??? One is a Sierra 18-3583 that is the all in one replacement for Volvo and Merc 350 engines. The 2nd pump is stamped MPR made I think in the East somewhere, ALSO NEW... THE MRP brand IS THE PUMP that was on the motor that I TOOK OFF originally. Here's my issue, the new Sierra has a built in restriction from the factory on the 5/8 inch input side and the output or larger port that goes to my heat exchanger, the inside opening is narrower on the Sierra than the MRP. MRP has a wide open 5/8th hole into the pump, no restriction and the housing inside the pump to the large 1 1/2 inch hose is larger than the Sierra pump, so the MRP at least looks like it will flow or push more water. SO WHICH PUMP WOULD U USE THE ONE WITH THE RESTRICTION IN THE INPUT (OR THE MRP) WHICH LOOKS LIKE IT FLOWS MORE WATER. Both pumps have brass impellars that are exactly the same size or same impeller. This is weird to me I can not find any one that knows why these two pumps are designed differently, but both companies say they both are replacements, could the Sierra even though it looks like less water will SQUEEZ thru it help in keeping itself PRIMED at idle better over MRP. If so maybethat is the way to go or is the MRP just a higher volume pump that I should use|||? Sure wou}}ld appreciate a comment of any Kind Thank you in advance Bob"
