temperature

[dreadnought]

hi all, i have a bmc 1800 in my nb, the instrument panel is very old and i`m not sure if the temperature gauge is very accurate, its reading around the 87 degree mark on average, does this seem about right, many thanks

[alan_fincher]

If it is a skin tank cooled system, and the skin tank is adequate, then thed temperature should rise to around the opening temperature of the thermostat that your engine is fitted with.

the two common values for a BMC thermostat seems to be 74 degrees C or 82 degrees C.  As the gauges or the thermostats are not particularly accurate if you have an 82 degree stat then a reading of 87 degrees doesn't sound too far adrift.

If you ever have the thermostat out, it should have its opening temperature stamped on it.

[hider]

Buy one like this, cheap and very good, there are other sellers, if from China will be even cheaper but take time to arrive.

https://www.ebay.co.uk/itm/50-550-Laser-Infrared-Temperature-Gun-Thermometer-Thermal-Heat-Sensor-Gauge-IR/223471059239?hash=item3407e9c127:m:mHt8EjK0Gd4SeN36Z1PiuPw

 

Infra red thermometer, very handy for checking gearbox, stern gland, and alternator temperatures as well. 

[Grassman]

 

I am no expert but over the years I've been told by many people including so called experts that 87 degrees is fine for a BMC 1.8. I used to often run mine at 95 degrees when on rivers with no problems. A couple of people have told me that you can run a BMC 1.8 up to about 98 without doing any damage.

 

When it was in for blacking I noticed that there was a thick layer of blacking on the skin tank. I completely removed it and just painted on a thin layer and the engine runs at a much cooler temperature now.

[Slim]

Mine's always run at 87 to 90 on canals etc. at about 1500 rpm. If pushed on a river it goes up a little. Provided you're happy with the appearance of the panel I'd leave well enough alone.

 

 

Frank

[Tony Brooks]

FWIW - you can even run an engine safely with the coolant boiling as long as you keep the cylinder head full of coolant. This is not some thing I would advise or think is fine. running at 100C or a bit higher because of the antifreeze and pressurisation should not cause excess expansion or damage anything - the problems start when there is no coolant in place to....... well, cool.