Oil Temperature range

[Lucky Phil]

6 minutes ago, pete roper said:

Don't be.

 

Apart from anything else it should be remembered that the original big block motor was designed to sit idling in Milan traffic in high summer with a fat Carribinieri sitting on top of it! Just about the only relevant changes to the design are the adoption of fuel injection and, with the advent of the Squarefin motor, even greater fin area. A thermostatically controlled oil cooler is a benefit but more so the faster one is travelling. At slow speed or a standstill the difference it makes is marginal.

Yes, modern engines run hotter but in all my years of working on them I've never seen problems caused by overheating as long as the lubrication system is working as it should. The Nuovo Hi-Cam motors as used on the CARC series bike do have an issue due to the sump spacer gasket blowing out on the lubrication side. This results in a loss of pressure which can cause damage but such a failure usually makes itself known by the camchains starting to rattle as the hydraulic tensioner plungers are starved of oil. It has caused big end failures but is fairly rare, (Although I replace the gasket as a matter of course during rollerisation of an 8V. There is a very much superior aftermarket gasket available that completely eradicates the problem.) just something to be aware of. It is NOT something I've ever known to affect any of the 2V motors.

As for heat? My Griso in high summer will heat its oil to >135*C in traffic. It's never caused me a problem. Conversely I worry more in winter as it's damn near impossible to get the oil above 75-80*C due to the cooling circuit not being thermostatically controlled.

Yes. Try to avoid getting stuck in traffic for hours in high summer but I wouldn't die in a ditch over it. The excessive heat is far more likely to cook the phase sensor than cause metallurgical or lubrication problems.

Beetle ( Mark) has done a very nice retro thermostat fit to your old Grisso you would be aware of Pete. Pricey but neat.Gives better fueling control and economy as well. 

Ciao 

[po18guy]

All transverse crank twins, V or L, have at least some cooling issues under some circumstances. Back in the mid 60s, it was substantially worse due to poor oil in comparison with what we run today.  At some point, that  might (or might not)_ have occurred to Guzzi engineers. And, those big jugs radiate heat 360º in addition to the oil cooler.

Do let us know what boiling water tests reveal as far as the readings of those two gauges.

[Lucky Phil]

6 minutes ago, po18guy said:

All transverse crank twins, V or L, have at least some cooling issues under some circumstances. Back in the mid 60s, it was substantially worse due to poor oil in comparison with what we run today.  At some point, that  might (or might not)_ have occurred to Guzzi engineers. And, those big jugs radiate heat 360º in addition to the oil cooler.

Do let us know what boiling water tests reveal as far as the readings of those two gauges.

You need to remember that the oil temp doesn't actually need to reach 100 deg C or 212 F to evaporate off the water. Put a pot of water on the stove and watch the vapour start rising way before 100 deg. It's just that obviously 100 deg C will make it happen more quickly. It will still evaporate off at say 90 or so but it takes a lot longer. So longer runs at a lower than 100 deg oil temp will still get the job done.

Ciao 

[4corsa]

Thank you Pete. The fact you've had your Griso to 135° with no damage will allow me to sleep much better at night!

[4corsa]

31 minutes ago, Lucky Phil said:

You know without knowing all the details here I doubt the traffic heat did your Ducati any real harm. I say this with confidence because in my race track experience I've never seen any engine that can cope with temperature abuse like a Ducati twin. I once saw an 851 superbike back in the day run completely out of coolant during a race and arrived in the pits with the cooling hose fittings (plastic in those days) melted off. Result? fit new coolant fittings and rectify the leak and back out for the next race with no issues.

I've seen another rider with a bike I know well sit at the end of pit lane idling the race bike until it boiled and started dumping fluid on several occasions and away it went without problems and was fine when pulled down. The rider had to be re educated to NOT head out as soon as pit lane opened and cruise down to the end and sit there and wait for the green flag. He was a owner/rider but didn't work on the bike and had zero mechanical skills or knowledge but he had deep pockets which made education on mechanical sympathy difficult.

I remember a delayed WSB race once in Italy when it was very hot and Troy Bayliss came back to his bike on pole position after going for a quick toilet break before the delayed start and gesticulating to his mechanic and pointing at the dash and the mechanic shrugging. Troy gave him the old Aussie "Arr @#!#$# it wave off" and the race got going and he won. I knew what he was gesticulating at........engine temp. It had overheated on the grid. Didn't matter though, still won.

There'r heat tough Ducati twins. Mechanically a bit fragile in those days but temp tough.   

Ciao

...but it seems all your examples are of water-cooled Ducatis.  My '95 900SS/SP is air cooled, and when sitting still that rear cylinder gets zero cooling.  It was not smoking before sitting in traffic that day. It's curious to me that the with '96 model year that added an oil temp gauge on the dash.  Must have been a reason for that.

[Lucky Phil]

11 minutes ago, 4corsa said:

...but it seems all your examples are of water-cooled Ducatis.  My '95 900SS/SP is air cooled, and when sitting still that rear cylinder gets zero cooling.  It was not smoking before sitting in traffic that day. It's curious to me that the with '96 model year that added an oil temp gauge on the dash.  Must have been a reason for that.

Doh, you're correct. My amazement at their temp tolerance was always sort of linked to their Nikasil cylinders and their resistance to seizing which your 900 had as well. When sitting in traffic the front gets virtually no cooling either. The front cylinder on a Ducati only cools better when on the move. Like all air cooled engines cooling is marginal when at rest no matter what the configuration.   

Did it continue to smoke after the sitting in traffic situation? The usual issue with overheating with regards to pistons and cylinders is the rings lose thier tension and the cylinders can glaze. Usually new rings and a run through the bore with a flex hone sorts the situation.

Ciao

[4corsa]

23 minutes ago, Lucky Phil said:

Doh, you're correct. My amazement at their temp tolerance was always sort of linked to their Nikasil cylinders and their resistance to seizing which your 900 had as well. When sitting in traffic the front gets virtually no cooling either. The front cylinder on a Ducati only cools better when on the move. Like all air cooled engines cooling is marginal when at rest no matter what the configuration.   

Did it continue to smoke after the sitting in traffic situation? The usual issue with overheating with regards to pistons and cylinders is the rings lose thier tension and the cylinders can glaze. Usually new rings and a run through the bore with a flex hone sorts the situation.

Ciao

Yeah, smoked all the way home. Ended up needing a new cylinder and piston/rings. Expensive lesson, so hope you can understand my sensitivity to this subject!😁

[4corsa]

1 hour ago, po18guy said:

All transverse crank twins, V or L, have at least some cooling issues under some circumstances. Back in the mid 60s, it was substantially worse due to poor oil in comparison with what we run today.  At some point, that  might (or might not)_ have occurred to Guzzi engineers. And, those big jugs radiate heat 360º in addition to the oil cooler.

Do let us know what boiling water tests reveal as far as the readings of those two gauges.

Ok - here you go. The gauges are different manufacturers, and the Guzzi stem is about 8" long and one for the Duc is only about 1". As you can see, there is about a 4°C difference between the two, the Guzzi gauge being the higher of the two.  Makes me feel a little better.

[Lucky Phil]

34 minutes ago, 4corsa said:

Yeah, smoked all the way home. Ended up needing a new cylinder and piston/rings. Expensive lesson, so hope you can understand my sensitivity to this subject!😁

Ok, I assume you had a shop replace it?

Ciao

[Lucky Phil]

30 minutes ago, 4corsa said:

Ok - here you go. The gauges are different manufacturers, and the Guzzi stem is about 8" long and one for the Duc is only about 1". As you can see, there is about a 4°C difference between the two, the Guzzi gauge being the higher of the two.  Makes me feel a little better.

Looks more like 6-8deg? or is there parallax error. 

Ciao

[4corsa]

You're right, it is more like 6°

[4corsa]

13 minutes ago, Lucky Phil said:

Ok, I assume you had a shop replace it?

Ciao

Yes, SuperMoto Italia, a certified Ducati mechanic. Said it wasn't the first one he's done on a 900SS, and always the rear cylinder. He of course did a compression and leak down test first. I can't remember the numbers - was 20 years ago.

[po18guy]

Aha! So, it's Gravensteins to Red Delicious now! 

[po18guy]

5 hours ago, Lucky Phil said:

You need to remember that the oil temp doesn't actually need to reach 100 deg C or 212 F to evaporate off the water. Put a pot of water on the stove and watch the vapour start rising way before 100 deg. It's just that obviously 100 deg C will make it happen more quickly. It will still evaporate off at say 90 or so but it takes a lot longer. So longer runs at a lower than 100 deg oil temp will still get the job done.

Ciao 

Virtually all water evaporates at ambient (outside) temp, to think about it. If it didn't, I doubt we'd have any clouds. Anyway, the 100ºC/212F I suggested was only for a point of reference and was 1) within the gauge's range and 2) close to the temp of oil in a running engine.

Mystery solved. Water evaporates. Oil evaporates, but in-laws never seem to.  

[Lucky Phil]

1 hour ago, po18guy said:

Virtually all water evaporates at ambient (outside) temp, to think about it. If it didn't, I doubt we'd have any clouds. Anyway, the 100ºC/212F I suggested was only for a point of reference and was 1) within the gauge's range and 2) close to the temp of oil in a running engine.

Mystery solved. Water evaporates. Oil evaporates, but in-laws never seem to.  

Yep, I just highlighted it because people seem to worry if they dont achieve 100 deg oil temp then it wont evaporate off moisture at all. Long trips with moderate oil temps will get it done or shorter runs at 110.

Ciao