header tank

[allan horsfall]

Peter,

Dont mean to teach Granny to suck eggs!!! but the thermostat hole is at the top of the thermostat?

Allan

[David Large]

My system, to original spec, is particularly difficult to fill. Best technique is to fill the header tank, then top up using the highest point you can achieve - which in my case is the input hose to the heater, disconnected and held up above the scuttle. There is an air bleed screw in the rad top hose, so I fill via the heater until water comes out of the top hose air bleed.
I always make sure any thermostat has two 1/8" holes drilled in the base plate, one at the top and one at the bottom. But this is AC's production system, obviously - not modified.
An interesting note from the 'Ford Cobra Guide' of 1964 which Peter Adams kindly introduced me to is contained in the list of things SAC did to cars on their arrival at the Shelby works for engine installation. One thing they did routinely was to remove the 195° thermostat and substitute a 160° (a modification confirmed by Dan Case in the US, 'original' owner for over 40 years). I've done this with mine and it seems to have made a difference to running temperature, although this has not yet been tested in heavy traffic on a hot day.

Roger

Roger
Is there a bypass hose around the thermostat on your system?

David

[David Large]

If you lift the front of the car as high as possible on axle stands, does that help to expel any air from the system?

Paul

Paul,

I have been thinking about this. My top hose loops up to go around the distributor. If I lift the front of the car up I do not alter the geometry and I do not think it would make any difference.

David

[Roger King]

Roger
Is there a bypass hose around the thermostat on your system?

David

Yes, all stock Ford. Still needs bleed holes to fill properly.

[peterc]

Roger
Agreed, if the total cooling system can only cool down to let's say 85C then having the thermostat opening at 70C only slows down the time taken to get to 85. It all comes down to getting sufficient airflow through the rad which when stationary in traffic is down to the capacity of the fans.
Alan.
Yes, the hole is always at the top. My first thermostat by QH did not have a hole, only a notch in the closure disk which made bleeding the air out laborious. Swopped to another with a small hole and toggle but have since embarked on experimentation with differing permanent holes. Even tried 2 x 6mm holes but that made the engine run too cold so I currently run with just 1 x 5mm as a compromise.
David.
My top hose goes partly around the distributor and is about level with the main roof of the distributor top, not the HT connections. The top of the header tank is higher so it's not an issue.
I can take a photo if you would like.
Peter C

[David Large]

Peter

I feel fairly sure that the layout on your engine and mine will be very similar if not identical in respect of the top hose and the distributor.
The size, location (particularly level) and the function of the tank could well be different.

David