Engine Temp

[Trustme00]

Does anyone know the correct normal running temperature for a Mermaid JCB444
engine. I have fitted a new engine and gearbox to my work boat and the gauge shows 90 degrees

 

[fredrussell]

Celsius or Fahrenheit?

 

[Trustme00]

Hi Fred, she's running at 90 Celsius and I have never had a boat run this warm . Normal seems to be 80.
She appeared to have quite a restricted sea inlet so we have replaced this with brand new inlet and strainer. she is getting plenty of water but looking through all paperwork from Mermaid they don't actually give a working temperature. Boat isn't overheating but its niggling me.

 

[andsarkit]

The temperature is set by the thermostat. I can't find any details about the OEM part but a quick search gives this:

• Standard Thermostat Opening Temperature: The thermostat for the JCB 444 engine typically begins to open in the range of 76°C to 82°C (169°F - 180°F).
• Operating Temperature: Once warmed up and under load, the engine usually operates between 80°C and 90°C (176°F - 194°F).
• Maximum Recommended Operating Temp: Continuous operation above 95°C-100°C should be avoided, and temperatures exceeding 105°C are generally considered overheating.

How accurate is your temperature gauge? Can you check it against another gauge such as an infrared thermometer?
As long as the temperature remains steady under a range of operating conditions it would seem to be fine. My cars all seem happy running at 90degC according to the gauges.,
Obviously raw water cooled engines will run much cooler to prevent scaling in the waterways.

 

[Trustme00]

The temperature is set by the thermostat. I can't find any details about the OEM part but a quick search gives this:

• Standard Thermostat Opening Temperature: The thermostat for the JCB 444 engine typically begins to open in the range of 76°C to 82°C (169°F - 180°F).
• Operating Temperature: Once warmed up and under load, the engine usually operates between 80°C and 90°C (176°F - 194°F).
• Maximum Recommended Operating Temp: Continuous operation above 95°C-100°C should be avoided, and temperatures exceeding 105°C are generally considered overheating.

How accurate is your temperature gauge? Can you check it against another gauge such as an infrared thermometer?
As long as the temperature remains steady under a range of operating conditions it would seem to be fine. My cars all seem happy running at 90degC according to the gauges.,
Obviously raw water cooled engines will run much cooler to prevent scaling in the waterways.

Thanks for your input, i'm probably worrying unnecessarily but I will contact Mermaid Marine on Monday to order a new Thermostat and sender....... its a peace of mind thing.