How much water should I be pumping.

[Patrick]

While motoring my Cat 27 in Puget Sound, WA, my 5411 (raw water cooled) started to overheat. I closed the recirculation line via an inline ball value, forcing all water overboard thru the exhaust. (Note: I have a 3/8" ID thermostat bypass line). This slowed the temp climb but I had to throttle back to 2/3 to maintain 155 deg. Is this normal? My Oberdorfer pumps about 2.5 quarts per min at 80% throttle. Should there be greater volume or is this around spec? Thanks for the help.

 

[Dave]

Not normal temp, but normal flow

The 5411 pumps VERY LITTLE water through the exhaust. A little burb ever few is quite normal. But you should be able to run at wide open throttle all day without overheating. Pull the thermostat and run without it for a while. By removing the thermostat, the engine will run as if the thermostat were stuck open. If you overheat with the thermostat removed, look for blockages. If your OK, replace the thermostat. When you put it back, you will have to drain the air out using the outlet just below the thermostat.