Overheating after shut down & recommendation on thermostat

[PeterB]

My 63BJ7 temperature is great while running both parked and moving. My problem seems tobe after the can is run and shut off. Then the temp climbs and pops the filler cap and out comes the antifreeze. Also I was wondering what people’s opinions were between original type sleeved thermostats or the newer replacement style.

Thanks,
Pete

 

[TimK]

Leave about a 1 inch space (underfill) between coolant and bottom of radiator cap seal surface. Are you using a 1" neck 7lb. cap? -- which you should be. I'm using the sleeved thermostat--works for me.

 

[steveg]

My 63BJ7 temperature is great while running both parked and moving. My problem seems tobe after the can is run and shut off. Then the temp climbs and pops the filler cap and out comes the antifreeze. Also I was wondering what people’s opinions were between original type sleeved thermostats or the newer replacement style.

Thanks,
Pete

Peter,
There has been a lot of discussion about thermostats and overflow handling. You can search old threads by entering "thermostat" in the search field on the Healey Forum home page.

 

[John Turney]

The temperature usually climbs when the car is shut down. That's because the water pump is no longer pumping, and heat removal is reduced drastically. The temperature bulb (connected to the temperature gauge) is at the hottest part of the cooling system, so as heat continues to dissipate from the cylinders and head into the coolant, and coolant circulation is now only provided by the change in density as it cools in the radiator, temperature at the hottest point will rise for a while and then cool down.

As for dumping coolant, Tim is correct. Either leave about an inch in the radiator for expansion or add a coolant recovery bottle.