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Recommended Coolant

Discussion in 'Technical Help' started by ChrisDS, Mar 23, 2017.

  1. Genuinely Exe because I cannot see it, I can't see in this thread where someone has mentioned that regularly changing your antifreeze is a bad thing?????
     
  2. It's not the regularly changing bit that is in doubt, it is the using Ducati recommended coolant that is. Apparently they changed their minds after they had to carry out a recall on some of their bikes.

    See Android853sp's post on the first page.
     
    • Agree Agree x 1
  3. My experience is that the motor runs too cool at speed and then too hot when you slow down.

    68 or 70 degrees seems far too cool and nobody seems to know if the mixture is still rich at that temperature. If it is, then the motor is not performing at optimum efficiency.

    It's interesting to learn that Nelly as had a degree (sorry about the pun) of success with one of the additives claimed to provide more efficient cooling than the straight 50/50 recommended mix.
    Once below 30 mph, the engine temp rises very rapidly - always a worry but we probably worry about it more than we should because of the excessively cool running at speed.

    To stabilise things, I'm tempted to swap my thermostat for one that opens later, to bring temps up at speed and add some of the additive Nelly mentions to bring things down at the top end.
     
  4. OR, your 999 thermostat begins to open at 65c, which means the engine is designed to operate around that point for most of the time (it seems cool but that’s what it is supposed to be). For any engine the closer and longer period it runs to its design temperature the better, it means less fuel and easier control of power and emissions. When the coolant is cooled below 65c the thermostat will shut off the flow to the radiator or at least modulate the flow, when it is over 65c it will open until it is at its maximum close to and above 75c. If the airflow through the radiator is inadequate the coolant will heat up, the thermostat will fully open and eventually the electric fans cut in around 101, again wasting fuel. Running hot is not good and for an engine like a Ducati, cooler is better, it also means the oil gets an easier life. The normal engine running temperature is set by that thermostat and unless the engine is being raced or has a flow problem, adding expensive compounds to make it run “cooler” does not theoretically make a lot of sense (the thermostat still opens and closes at the same temperature).

    Once running, the engine temperature thermistor provides a varying resistance signal (reducing resistance with temperature) which the ecu uses to adjust the length of the fuel pulse, the variation can be as much as +50% if the engine is really cold. This means that the ecu is set up by Ducati to run the best mixture to get the best burn at the required stoichiometric ratio over most engine coolant temperatures including the normal 65-70c operating range you see on the dash. At 65c it will be burning as hot and as well as it does at 85c, 95c or 105c.

    To summarize they run cool but that is intentional, in my experience they tend to run worse when hot when the oil is working its hardest. They are used in climates significantly hotter than here with no significant issues

    FTR Ducati specify not less than 30% of the recommended coolant to ensure its corrosion inhibiting properties are effective. 35-40% coolant to water is normal although 55% can be used in very cold areas, they do not recommend using hard water
     
    • Useful Useful x 1
  5. 80 ish generally optimum running from what I know. This ties in with trims being turned off in the fuel maps etc.
    As a rule, this is fine and all runs to plan as Denzil says. The OP is running a tuned 955 motor on what I'm assuming is a stock cooling system which wasn't designed for the energy being put out by the motor...
    Once the stat has opened then the rad should keep things around operating temp with the stat controlling engine temp. Thing is, on tuned motors or old rads with damaged fines, blocked galleries etc. They can't cool it all down, even when the single fan comes on... (998 kept same rad but used two fans). Stat stays open and system temp rises as the energy simply can't be displaced.
    Simply going over the rad and straightening fins out and running a system flush can have significant effects to. The amount of crud and shit I've pulled out of 15 year old cooling systems is unreal at times.
    As a rule I wouldn't say a wetter is needed, but in the OP's case then I would certainly consider it. I've used it in track bikes running no fans for instance, a tuned 1198 and even a siedici with some success.
     
    • Useful Useful x 1
  6. What Chris DS said :upyeah:
     
  7. This is what I ended up with after some pretty patchy advice :smile:. Motul Motocool Factory Line Organic+. The bottles look nice, and the coolant is red. Hopefully it doesn't rot my engine.

    Motocool.jpg
     
  8. We use Motul Motorcool Expert, never seen any evidence of corrosion on bikes filled with it.
     
    • Like Like x 1
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