[T2] electronic thermostat

[Christophe Guilbert]

Hi guys , a while ago , I announced that I will do an electronic 
thermostat.
I did a prototype using an Arduino nano , a servo motor and a digital 
temp sensor which control the servo.
The electronic and servo are located in the engine compartment. Servo 
and arduino are voltage regulated against voltage fluctuations. The 
flaps are moved  by the servo motor using a regular bicycle cable which 
goes through the bracket which was holding the mechanical thermostat . 
So far it looks really good, I will post everything once this project is 
complete (soon) with details and video.

Meanwhile I would like some ideas/feedback about the way I should open 
the flaps according to the temperature.

I have mainly 2 problems.
1) Where to put my temp sensor.
2) Flap opening(%) curve according to the temperature (which is 
Dependant to 1)

So far , I wanted to install my (waterproof) temp sensor to the bracket 
holding (the now missing ) mechanical thermostat , however the optimal 
reading to open the flag of my sensor will be different than the one 
provide by the mechanical thermostat. why  ? well correct me if I am 
wrong but I suspect that since air is a great thermal insulator, most of 
the heat received by the mechanical thermostat will come trough  its 
metal mounting bracket which is attached to the engine. I probably will 
have to take care of that while programing point 2)

Now , I also have this other idea. Instead of using the thermostat 
bracket to hold my temp sensor , I can install an (none contact) 
infrared temperature sensor just on the top  of cylinder III (by 
drilling a small hole trough the tin to accommodate the sensor) and use 
that temperature to control the flap. In this event what, should be 
point 2) ???. I like this idea because I the control of the flap will be 
the reflection of areal  cylinder temperature. I can also attach an LCD 
display to my Arduino to monitor real time the temperature and even put 
an alarm using a buzzer in case the flaps stay open too long , I also 
wont need any thermocouple temp sensor attached to the spark-plug anymore.

Also , arduino has an endless possibilities , I would like to use it as 
a mini computer for my bus later on .
I plan to check the voltage , RPM, oil temp , cyl temp, etc ....

If you guys dream to add something to my project , what would it be?

Thanks for any discussion.

Chris