Cooling vs air temperature and optimum engine temp.

[canuguzzi]

Just curious.

Take the current 8V engines (or the others if it doesn't matter much), is there an air temp at which the engine would not reach an optimum operating temperature?

I'm not talking about a theoretical temp at which you wouldn't or couldn't actually ride. Since our air/oil cooled engines (the 8Vs) don't have temp regulators as do many liquid cooled bikes they must be limited somehow to the temps at which they aren't able to maintain optimum operating temps.

I've ridden my Norge in 105-110 heat at highway speeds and it seems not to affect the cooling to a point of any concern, that I know of. Above that temperature I think the heat drawing moisture from your body would start turning you into a prune so its sort of self limiting.

Is there a threshold for the air/oil cooled big blocks on MGs on the low temp side at which you would not ride anyway? Some of us will ride below freezing, I did when I lived back east and frostbite makes sure I'll not do that again without heated clothing. It was a Yamaha XS500 at the time. Wonderful bike.

[pyoungbl]

There is some discussion about oil temps over at AdvRider, specifically on the 8V Stelvio.  Same engine, different bodywork and cooler.  With the cooler blocked off this:

Oil Temp news . . .
Ride home this morning, same mix of Urban-Motorway-Urban, 7°C, but raining fairly steadily.
Never got above 85° on the M/way doing 85-90mph (0440, so nice and quiet!), crept up to 95° the three miles through Town from M/way to Home, then went up to 105° sitting idling for two mins once I got home.
 
 he has covered his oil cooler and still can't get the oil hot enough to boil off moisture unless at idle at home.

more info here: http://advrider.com/index.php?threads/moto-guzzi-stelvio-merged-threadfest.113158/page-777

[Perazzimx14]

I know my DR650 will not get to ideal oil temp (212* to boil off condensation) even blocking the oil coolers air flow once the mercury dips into the 40's. I still ride the bike into the low teens.

[cruzziguzzi]

I should think looking at air cooled civil aircraft might show that extremes which might overtly affect your bike are unlikely to be encountered.

Ambient temperatures relative to cooling/warm-up, intake temps and the like probably won't matter much to the average fella once the bike's started.

Reading a lot of German and some U.S. recounting of cold weather operation - they were far more concerned with simply starting than running. That, beyond issues of snow pack in inductions or lubrication drag.

Sludging anomalies and oil grade and composition might be a consideration though if the temps stabilize on the very low side - that and starting ease.

Todd.

[Vasco DG]

Yes the 8V is massively overcooled. The fact it doesn't have a thermostat doesn't help.

As long as the temperature correction, air and engine, is correct in the map though it should run fine in any conditions it is ever likely to be ridden in.

pete

[canuguzzi]

Is it then fair to say that regulating the temp such as using a bypass valve set to optimum operating temperature doesn't really provide a benefit? The reason for that question is that having purchased one but not yet having installed it, why bother with the effort if no real benefit would be realized.

Riding temps would in in the 30s, not often but happening and frequently in the low 40s at highways speeds, not in town nor long idle times.

I was pleasantly surprised at how well the engine performed in very high temps that would have had some other air cooled bikes sounding rather ratty.

[Bonafide Bob]

 I read on the Jagg oil cooler site that their by pass valves start to open at 185 degrees and are fully open at 195 degrees. The question was asked if oil needs to reach 212 degrees to remove water, the answer is below.

 Does my oil need to reach 212° to burn off the water?

"No. Water prefers to separate from oil at ambient temperature. When the water/water vapor in your oil system encounters any hot engine component, the separation process is accelerated"

 

[Arizona Wayne]

For different comfortable air cooled motor references, I've found my big block Guzzi motors most happy @ 95F ambient temp.  The valve tappets are quiet then.

Repeatedly I've run my 750 Breva small block uphill for miles @ 65 mph @ 110F and it was fairing better than me w/o a sump extender!

Repeatedly I've run my water cooled 400 MP3 for over 100 miles @ 70 mph @ 122F and it didn't miss a beat!   Temp gauge never got near it's limit.

[JeffOlson]

I am riding my Norge in the 30s, 20+ miles each way. Hopefully it is getting warm enough.

[canuguzzi]

Jeff, I just spin the engine a little faster. Run 5th instead of 6th unless the speed makes 6th necessary.

AW, yes, I noticed the Norge very quiet at higher temps and it runs well there.

[Arizona Wayne]

I am riding my Norge in the 30s, 20+ miles each way. Hopefully it is getting warm enough.

Without an oil cooler it takes at least 45 min. of constant running an air cooled motor at say 60 mph or more to get moister out of the motor/tranny(aka mayonnaise).  If I ran a MC Air/Cooled motor w/oil cooler in cold conditions I'd block off the cooler just like semi trucks block off their radiators is such conditions.

[JeffOlson]

^ My 20-mile commute can take 60 minutes...