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- Jul 18, 2011
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- 17,624
I just finished installed a closed cooling system - the FULL system type - on the port side engine. Mercruiser 7.4 LX MPI (see sig.)
So, I loaded it up with coolant, hooked up the muffs and gave it a few test runs for about 15 minutes total. Well, the first thing I noticed is that the engine ran a bit hotter than before it had the closed cooling system. It goes up to about 170-175 and fluctuates in that range. So, I assume that the thermostat is doing its thing (160 degree thermostat).
My concern is that the engine used to run in the 155-165 range. Since the closed cooling system is cooling the exhaust manifolds, there is a lot more heat going back to the engine and the heat exchanger.
I checked the original T-stat and that is a 160 degree, same as the new one with the new cooling system.
FWIW - this is the SJE #MC324 "Full" closed cooling system.
I am just concern about the higher operating temps with no load, and it will probably go higher with load . . . more in the 180-185 range. Plus, from a cold start, the exhaust manifolds get very hot before the t-stat kicks in . . .
So, perhaps I should go with a 143 degree thermostat or just do without the thermostat all together.
What do you all think.???
So, I loaded it up with coolant, hooked up the muffs and gave it a few test runs for about 15 minutes total. Well, the first thing I noticed is that the engine ran a bit hotter than before it had the closed cooling system. It goes up to about 170-175 and fluctuates in that range. So, I assume that the thermostat is doing its thing (160 degree thermostat).
My concern is that the engine used to run in the 155-165 range. Since the closed cooling system is cooling the exhaust manifolds, there is a lot more heat going back to the engine and the heat exchanger.
I checked the original T-stat and that is a 160 degree, same as the new one with the new cooling system.
FWIW - this is the SJE #MC324 "Full" closed cooling system.
I am just concern about the higher operating temps with no load, and it will probably go higher with load . . . more in the 180-185 range. Plus, from a cold start, the exhaust manifolds get very hot before the t-stat kicks in . . .
So, perhaps I should go with a 143 degree thermostat or just do without the thermostat all together.
What do you all think.???