I think it would be worth removing the thermostat housing. Sometimes people remove the thermostat thinking that the water flowing more quickly will help with cooling but this sometimes has the opposite effect. If there IS a thermostat just drop it in a pot of water and bring it to the boil and check that it opens up when it should, opening temperature is usually mark on the thermostat.

Apart from regulating the temperature of motor the thermostat also helps when the car is first started (cold) by preventing the circulation of water to the radiator and helping the engine to warm up more quickly.

You could get a rough idea of what's happening with the temp by taking off the radiator cap as you warm up the car and placing a thermometer in the coolent and comparing it with the temp gauge. It's important that you can trust your gauge is telling you the truth!




Sent from my iPad using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

there's also a good change the previous owner fitted a 72° thermostat - standard is 82° (isn't it?)

_________________
did I tell you that I won a trophy?

82C common in Australia. I used to run a 74 but my tootsies were too cold in mid winter.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Well the guy said that the gauge doesnt go over a qtr, so he may have the wrong one in?

'wrong' mightn't be the right way to put it, he might've put in a 74° (thenks Kev) thinking it was the best option because "minis always run hot", but in reality, if everything on the car is up to scratch then an 82° is the ideal

get hold of an infra-red temperature gun thingy and shoot it at different bits of the engine & radiator when it's at running temp, theoretically the temperature of the engine will be the thermostat's operating temperature

_________________
did I tell you that I won a trophy?

or after a long run, if the rocker cover and engine are too uncomfortably hot to touch...then you know you are getting up to temperature.

The other thing to look out for is listen for bubbling/gurgling when you come to a stop after a long run (it can take a minute or two) which can indicate boiling...a little is normal but prolonged is not..going on what you have said, I doubt you will hear this.

_________________
"Show me the Mini!"

Thanks mate, I think it could be the temp sender, as i ran it for a while and it def got hot, but the gauge hardly moved. Can these "fail"?

(BTW There is a thermo in the housing)

Easily tested by taking it out and sticking it in a pot of hot water (or cold and heat it up)...attach a multimeter to it on resistance and there should be a change of resistance with temperature.

Otherwise, it could be a poor connection and/or wiring...unlikely that it is the gauge...

_________________
"Show me the Mini!"

Test as above or even better take sender out of head but leave connected, you might need to extend the wire, earth the outside of it with a clip to the car, immerse the tip of the sender in a kettle and slowly bring to boil. If you have a thermometer you will be able to see what "normal" is on your gauge and at what point is 100deg.

Make sure you disconnect your coil because you will have the ign on the whole time and you don't want to burn anything out.

The other component that sometimes play up is if there is a instrument voltage regulator. The electric gauges often need a constant 10v to be accurate. If this is faulty it will usually effect both the temp and fuel gauges.


Sent from my iPad using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)