Just to be clear, I have extremely consistent coolant temps at 82c which is not an issue at all, however, strictly speaking the Duratec is designed to run a lot hotter at around 105-110c, and with the aid of an ECU controlled electric thermostat. For the record I'm logging true coolant temps at the head using my EMU Black standalone ECU, I am most certainly not relying on the readings displayed on the comedy instrument in the dash. I've proved this effort from Caerbont Instruments (the old Smiths factory) under reads by 10c or more depending on hysterias and mood, actually during the warm up phase it can be as much as 30c off as its rediculously slow to respond!

Morgan did use the Ford/Visteon ECU which has the capacity to control the electric thermostat, however, for whatever reason they chose not to implement this feature preferring instead to use an old school mechanical thermostat. Caterham who has also extensively used the Duratec engine over many years use a mechanical thermostat too, this may be because they use an ECU from MBE and it's not capable of controlling Ford's electronic thermostat, but I suspect its more than that.

Whatever the reason, it does seem everyone fitting a Duratec in a rear-wheel-drive application bins off the electronic thermostat, preferring instead to go mechanical with all the people converting Mk1/2 Escorts to Duratec, Frontline Developments, and I suspect every kit car maker out there do the same. Now, if you read the Caterham, Escort and Locost forums you to tend to see a clear theme in the posts around over cooling, which I believe is partly because the whole cooling system in a Duratec was designed from the outset via an electronic thermostat in mind, and partly because when everyone fits a mechanical a mechanical thermostat they fit an 82c one so perhaps that’s the only value available?

I do also have a breakdown somewhere from Rog on how the Duratec cooling system was designed to work in the OEM application, and all I’ll say is it’s a bit unconventional, undoubtably this is Ford finding new weird and wonderful new ways to accelerate the warmup phase and get their engines to run cleanly at Lambda 1 as soon as possible. These excessively complex additions such as electronic thermostats, electric water pumps and odd ball cooling system designs have all appereared in an attempt to come out of cold start enrichment just a few seconds quicker in order to meet ever stricter emissions standards.

At the end of the day running any engine at 82c is just fine, so I’ve elected to leave Monty like he is rather than push my coolant to 95c, only to potentially run into the real reason 82c is the go-to RWD stat value. Afterall, at even at just 82c Monty’s heater is fantastic and the engine is massively under it’s limit, saying that you can see Caerbont Instruments knew what temp the Duratec is meant to run at just by looking at the gauge scale.

[Linked Image]
[Linked Image]
image upload

You can clearly see the engine is meant to run at the mid point of the gauge, i.e 110c winky