I recently posted this on another thread before I found the Cal 31 thread. I would appreciate any comparison data other Cal 31 owners are able to provide:
I have a Universal 5416 installed in my 1980 Cal 31 and am evaluating my cooling system for proper performance. I have the performance specs for my particular raw water pump
, but would like to conduct an informal survey of Cal31 owners with Universal 5416 (M-20) power for which raw water pump
people are using and what amount of total raw water system throughput they are seeing.
My measurements, taken from a bucket on on a line
collecting water from the exhaust
, are as follows:
Engine: Universal 5416
Raw Water Pump
: Moyer Marine MMI 502
Raw Water Throughput at 1,800 engine RPMs: 7.5 quarts per minute
Raw Water Throughput at 2,000 engine RPMs: 8 quarts (2 gallons) per minute
After removing, cleaning and reinstalling the heat exchanger and replacing all raw water lines
, I am now up to 11-12 quarts (3 gallons) per minute @ 2,000 engine RPM. Given that the 5416 has a camshaft mounted raw water pump
, that means the pump speed is half the engine RPM, so total system throughput is close to the rated pump specs of 3.5 gallons per minute @ 1,000 pump RPMs.