Coolant and Heating running temperatures

Petrol engines

Grun: Haynes says thermostat fully open at 105 celsius.

Radiator fan, carburettor engines:

1st speed cuts in at 93 to 98 C

cuts out at 88 to 93 C

2nd speed cuts in 99 to 105 C

cuts out at 91 to97 C

Fuel injection engines:

1st speed cuts in at 89 to 94 C

cuts out at 81 C

2nd speed cuts in at 95 to 100 C

cuts out at 87 C