Sprint water temp, whats Ideal?

[tony g]

So in my re-route of the water flow around my sprint engine, I have k type thermocouples connected to back of the head (on my home made plate with thermostat inside). Also top hose into rad and bottom hose pre pump. The stat Im using is an MX5 as its compact and I already had a housing for one.
The warm up is slightly odd at the moment but its getting better with trial and error. The stat is an 88 deg unit and seems the only option for MX5's.

When fully up to temp the fan cuts in at 92 deg and drops temp to about 88 deg. It will do this all day long in the workshop (I havent been out on the road yet due to saltyness.
What do we consider to be a good running temp on these engines? I dont want to go too low because it becomes inefficient on fuel and heater may suffer (its brilliant at the moment), but also I dont want to high in case the cylinder head doesnt like it.

Cheers

Tony

[tony g]

I have now found an 82 deg option too, if people think thats better?

Cheers

Tony

[Galileo]

The stat temperature is the starting to open temperature, not the fully opened temperature which is usually about another 10-15°C above. You would ideally be looking for a coolant temperature range of 85°C to 95°C for optimum efficiency and low wear characteristics.


Edit: Clarity.

[gmsclassics]

Given your fan is cutting in at 92, I would certainly go for a 82 thermostat. That is the setup I have. It gives you some leeway when driving but means the fan should not come on whilst driving at reasonable speeds, only when stopped or in slow moving heavy traffic.

I've also wired my fan from the always live side of the fusebox rather than the ignition on only feed. That way it will continue to run after the car is parked, bringing the temperature down.

Geoff

[tony g]

I still yet need to drive it and log the temps that way and in this cold weather I expect the fan wont come on except when stood still for a while. I think I'll grab an 82 just in case . Once I'm fully up to temp the 3 readings Im taking at the mo are all looking very close so Im happy the front and back of the engine are getting similar temps. Ive got some clear hose coming to test the direction of flow from cold to hot.

Cheers

Tony