As above really.
I'm using Smiths dial's , so ordered a Smith's sender, this is about 2 year's since, but my car always seemed to run hot , so
removed thermostat to keep temp down. Now i have fitted newer engine it still runs hot , so tested today, the thermostat only opens at 120 even thoug
i know the engine ran at 90 before. So , is it the wrong sender , or could it be somthing else. HELP PLEASE.
How did you test the thermostat? If you checked it in boiling water you must be well below sea level 
I would change either the thermostat as it should open at about 70 IIRC.
I think he is saying that when the thermostat opens, the temperature gauge reads 120, ie, the temp sender is faulty.
He should remove the temp sender from the block and immerse it in boiling water and adjust the gauge to read 100.
Is the temp gauge fed from +12V, or through the volts regulator at about 9V ?
Well , i have just levelled my rad to eliminate trapped air, then just let the engine tick over until i could feel the top hose getting warm, then
looked at the temp reading, the thermostat should be ok.
quote:
Is the temp gauge fed from +12V, or through the volts regulator at about 9V ?
That might be it then, I think the dials should generally be fed through a volts regulator otherwise the readings will vary with engine speed. For ex
..the faster you go, the more petrol you have in the tank
quote:
Originally posted by Macbeast
..the faster you go, the more petrol you have in the tank
I know my speedo is correct , it is an original MGB gt dial , but my fuel and temp gauge are brand new and my fuel gauge read's incorrect also
when full or empty, so the voltage could be effecting both.
I think that most, if not all, smiths gauges need a voltage regulator/stabilizer, (dont know what its called), if you fit one in the supply to the clocks your problem should be cured. HTH Ray.
Off the subject a little, but never remove thermostat without fitting a restrictor in its place. The water in head will boil...........nuff said?