Originally Posted by Heinz
Originally Posted by RichardV6
Interesting subject thermostats Heinz. Not all of a particular advertised temperature work the same. The opening range is equally important. I was given an "80°C" thermostat to cure overheating on a vintage marine diesel engine, replacing the previous 72°C one. It worked because the high temperature one actually started opening at 65°C. I suspect a new thermostat alone would cure your issue Heinz although admit a lot of thought, sourcing and experimentation would be needed. This would allow full use of your larger capacity radiator, possibly required in extreme circumstances.

Note after 2006 MMC fitted the same radiator to all Classics so the cooling system didn't have the benefit of custom tuning of system that Ford would have made to each of its cars.


That's certainly worth considering, Richard. Because as it is now I can not really take advantage of the benefit of the larger radiator, for example, in a traffic jam in the hot summer or I have to change the area of the cover of the radiator more often, so less in summer, more in autumn and winter.
Your thought seems very conclusive to me. Already on the standard Ford, yes, the thermostat is an 82 degree (from memory) type so the engine reaches about 88 to 90 degrees. On a conventional cooling circuit with a thermostat before the radiator intake, it would be an 89 degree thermostat to keep the engine at 89 degrees.
But in my case, without the radiator cover I might have to install a type with a characteristic that might open as early as 75 degrees (as an example) but then also stay closed until, say, 82 degrees. And I agree, all possible Ford engines, from the 1.6 to the 3.0 had the same radiator in the Morgan which is not the Ford philosophy.

Maybe for fun I'll install a 77 degree type or similar if I can find a thermostat that fits the Ford mechanically. Another difference to the conventional circuit is that when the thermostat opens, the cold water flows through the direction of travel and not the hot water...and that the thermostat must react to the mixing ratios of the temperatures it feels from both sides....quasi a temperature mixing sum must move it to open

It’s not difficult to see Ford's original rational for controlling the stat with an internal heater element operated by the ecu when these engines were first introduced. Whenever there was a sudden peak demand on the engine the stat at the bottom just couldn't react in time for the rapid rise in head temp so the ecu took control and opened the stat. Ford did it like this for several years in the first Duratecs Mondeos however the heater was dropped around 2004 after some changes. I guess they might have balanced the system a little more precisely after that. But the effect could be seen on my 4/4. On a cold day if I were to blast up a hill and get the head temp to around 100C, causing the cooling fan to come on I could stop the car quickly, jump out and feel that the bottom hose was dead cold with the cooling fan running. The stat would be shut with no coolant circulation around the primary circuit. There was nothing wrong with the stat because if you let the car heat up from idle without the forced cold air flow through the rad the stat would function normally. A subtle quirk that might easily go undetected...

Like you I was concerned but concluded that I was chasing my tail fitting different stats and blanking the rad. I even considered fitting the early stat with the 12v heater element and driving it from an independent temp switch located on the top hose. Stats with heaters are still available at least for the Duratecs and can be retro fitted. I even went as far as sourcing an adjustable switch. It wouldn't have been that difficult and a fun exercise.

I guess this is all progress....

Roger
2011 Plus 4