Operating temperature

[riascns]

Had a thermostat from an Aprillia 1000 installed with normal operating temperature of about 85 centigrade.

I recently fitted NOS thermostat which was genuine ducati 851 and this has a normal operating temperature when driven of 75 centigrade with an air temperature of 7.5 centigrade. The bike when standing will reach 88 centigrade before the fan starts.

This driving temperature seems too low, or is it normal for the 907?

[higgy]

The nominal and generally accepted normal operating range for any IC engine is 85 to 90.5C(185-195F)
Now since we are talking about a bike with a small capacity for heat exchange the closer to the low end the better off you will be

[viciouscycle]

I'm a newbie to this bike...in fact mine is not even running yet, so any opinion I have is either from my readings or theoretical. I agree with Higgy's comments about operating temperatures in general. I recently acquired a copyt of LT Snyder's book, Ducati desomdue/desmortre Maintenance & Modification Guide (3rd ed). I always like to get manuals as soon as I get a bike to learn how they are put together. The 907 has been a problem as I could not find a proper manual for this bike. Snyder's book is the best I have seen so far.

In the cooling section on page 103 there is the following Q&A:

Q: LT, I read on a Ducati message board that I shouldn't install a fan switch because the engine SHOULD be running warm - around 200 degrees, because that is the optimum temperature for the motor.

A:While cooler isn't necessarily better, I've found the sweet spot for running temps to be around 170-180 degrees F. However, you'll see running temps between 155-210 degrees F. on any given day. A manual fan switch can be used to keep the motor in it's sweet spot, partiuclarly in stop-and-go traffic. Obviously, the motor isn't so sensitive that you'll cause damage to it should it run near 220 degrees F., but in my opinion, your motor faces less stress when the temps are kept below 200 degrees F. Fan switches are controlled by the ECU. Higher output motors create more heat and are designed to run at higher temps. The other way to turn the fan on sooner is by installing an FIM chip (only available for the P8 and 16M variants of ECU).

The 907 has a P7 ECU so I do not believe there is a chip fix. Snyder goes on to say that on average the relays are designed to kick in at about 220 degrees. Desmotimes.com (Snyder's company) sells a replacement fan that is more efficient than the stock unit as well as a kit including a switch where the switch does not cut out the ECU relay so you still have that as a fallback.

I was thinking of going this route but the feedback I received on this board suggested that I needn't worry about the 907 overheating. I live in Vancouver, BC but often ride through the mountains or down south where the temps can go well above 100 F. For me, I will use the best coolant and see how the bike does this year before fiddling with it. From this info, though, if I see the temp gauge going above 200 F I will try the desmotimes kit.

[higgy]

BTW, the 906 and the supplement to it for the 907 manuals are here in the downloads section

[riascns]

Thanks for the info.

Not sure about ECU and such. My bike runs a simple thermoswitch for the fan which is independant of ECU operation.

I think I will run the bike for a while and see how it goes. Running too cool or too hot can lead to trouble but I get the impression that the bike prefers being cool to being hot.