BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

This may be a bizarre question, but the need to know is killing me: How does the engine know what temperature it is? Even on the coldest days I've ridden, 36 F, the temperature gets to the lower limit mark on the gauge fairly quickly, then stays there. Even on the hottest day, 90 F, in heavy traffic going up hill, it didn't go over the top limit mark. I understand automotive thermostats, but an air-cooled engine?! What gives?

I don't know but I have the know-it-all gene really strong (generally follows the male side of the family, kind of like color blindness - but I digress).

In my old Suzuki Katana 1100, which had a similar oil/air cooling system, there was a bypass designed into the oil cooler plumbing. When the oil was cold and thick it opened a spriing loaded valve and didn't pass through the oil cooler. As it got hotter and thinner the valve closed and allowed the oil to go through the cooler. Don't know if that's how BMW does it or not. In the Suzuki there were actually 2 separate oil pumps - a low volume high pressure pump for the lubrication system and a high volume, low pressure pump for the cooling system.

The engine isn't air cooled. It's oil cooled, with a thermostat that regulates the oil passing through the oil cooler (radiator) on the front of the bike. The fins are mostly for decoration.

deilenberger wrote:The engine isn't air cooled. It's oil cooled, with a thermostat that regulates the oil passing through the oil cooler (radiator) on the front of the bike. The fins are mostly for decoration.

Well, Oil be damned. Is that the significance of "oil heads" being called oil heads, and the "hex head" is an oil head, too?

famousperson wrote:

deilenberger wrote:The engine isn't air cooled. It's oil cooled, with a thermostat that regulates the oil passing through the oil cooler (radiator) on the front of the bike. The fins are mostly for decoration.

Well, Oil be damned. Is that the significance of "oil heads" being called oil heads, and the "hex head" is an oil head, too?

EdZachery

It's a clever solution since it eliminates an entire layer of complexity involved with a water based cooling system. And you never have to worry about your oil freezing or boiling over (probably..)

Speaking engine temperature and oil cooling.

The Oli Cooler guard a number ofy ou'all have added looks pretty good Except


Most gaurds seem to be less than 75% "free flow", thus should reduce cooling.

AND

If you mount the guard against the oil cooler what good does it really do?

parkec wrote:Speaking engine temperature and oil cooling.

The Oli Cooler guard a number o fyou'allhave added looks pretty good Except


Most gaurds seem to be less than 75% "free flow", thus should reduce cooling.

AND

If you mount the guard against the oil cooler what good does it really do?

It might seem like it could be a problem, but apparently BMW oversized the oil cooler on the R12R - since in 2 years of use of a guard - in all sorts of weather and temperatures, I've never seen the oil temperature get near the "hot" portion of the scale. I have seen people who've used a wire-mesh type guard instead of perforated metal - probably provides more airflow at the expense of less protection.

I also suspect that simple convection airflow through the cooler is adequate in most instances when the bike is moving slow or is stationary, and the guard wouldn't greatly change this.

I can only speak of my experience - I've had NO problems in 25,000 miles. The perforated metal one I use is strong enough to stop a stone that might puncture the rather soft aluminum of the oil cooler.. and that was my intent in installing it. Since I also added an extension to the front fender (Pyramid Plastics from the UK) - it's probably less important than it was. Before the extension was added the cooler did get covered with mud when I went through puddles - meaning any stones tossed up would also hit the cooler. Not the case since the fender extension was added.

YMMV and FWIW and it's your ride - do with it what'cha want..

deilenberger wrote:It might seem like it could be a problem, but apparently BMW oversized the oil cooler on the R12R - since in 2 years of use of a guard - in all sorts of weather and temperatures, I've never seen the oil temperature get near the "hot" portion of the scale. I have seen people who've used a wire-mesh type guard instead of perforated metal - probably provides more airflow at the expense of less protection.

I also suspect that simple convection airflow through the cooler is adequate in most instances when the bike is moving slow or is stationary, and the guard wouldn't greatly change this.

I have seen the temp. gauge get right to the top.

During my break-in period, with the light break-in oil, I got stuck in a highway traffic jam (stop-and-go traffic) around San Francisco. Ambient temp was mid-50's and it was raining (so the air wasn't too warm and the rain should only have helped with cooling). The temp. gauge went to the top and the oil pressure light started flickering, so I shut down and worked my way to the side to let her cool off for a while. The light oil would probably be better at transporting & dissipating heat than the 20W50 in there now.

So ... at the risk of disagreeing with Don ... convection cooling is not sufficient with these bikes, at least in my experience. You need air flow.

Good roads,

- Lewellen

No risk of disagreeing - I'm just reporting my observations. Today was a good test.. left my house it was 65F - headed west to a Ducati open house at my dealer (they are BMW, Duc, Victory, Triumph) - on the other side of the state. By the time I got there it was 85F. I had glanced at the temp gauge on the highway - it was sitting right on the lower OK range bar (the extended bar near the bottom.) Got stuck in traffic where I was crawling for about 15 minutes - it went up to one bar above that. Headed back home - it was foggy and in the 50's when I got there - back to the low OK range bar. It never went more than 1 bar into the OK range (between the two longer bars.) - even when sitting in traffic idling in 85F.

Dunno why your bike apparently overheated in conditions I wouldn't expect it to.. but I suspect something related to the break-in might be the reason.

OTOH, I've been stuck in stop and go traffic, in 90+ degree weather, and the oil temperature did not go to the top of the gauge. I can understand loss of oil pressure at idle when the oil is hot, especially with lighter-than-normal oil (do we KNOW that the break-in oil is lighter than normal?), but I'm wondering if you have a problem with your cooling thermostat or the calibration of the gauge.

deilenberger wrote: - headed west to a Ducati open house at my dealer (they are BMW, Duc, Victory, Triumph)

DUC GIRL PHOTOS ?????

Ducati Hotti and my last years traveling partner. Taken at the Ducati Party during Daytona.
The little guy made it to Daytona,Laconia and Sturgis last year.

It just occurred to me that BMW needs some hot biker babes to promote the RR ~

Not sure what this has to do with engine temperature, but I guess it depends on the engine !

This temperature thing has me perplexed.
My bike has always gone to the top of the normal range of the temp indicator when standing in traffic. This is during the heat of the summer of course, but its common during those months that my bike is only running one or two bars below the top while moving and it moves right to the top when I'm at a standstill.

I've had no issues with the bike, only a concern every summer of overheating when I'm commuting in Boston. A concern many have, but few report the same temp gauge results as me.

I'd also like to add my support for BMW beauties to compete with the Ducati Hotties.
Like BMW's the girls would have to be both beautiful and practical, so...who would that be exactly?

today in traffic on a los angeles freeway i lane splitted for aboiut 20 mins in first gear going towards the fast end of the gear - and the temp gauge was 2 from the top. it was about 80-85 F out. i suspected it was more due to the engine running in low gear for so long but who knows.

regardless, my bike was still far from being too hot i'm sure.

wes

vielzebub wrote:Like BMW's the girls would have to be both beautiful and practical, so...who would that be exactly?

"A college student, an engineering major, comes back to his room and finds his roommate, a math major, looking very depressed. 'Hey, man,' he asks, 'What's wrong?' His roommate replies, 'My girlfriend suggested we play a game. She'd stand at one end of the quad, and I'd stand at the other end. Then we'd walk toward each other, so we're only half the distance apart. And then we'd repeat the process, halving the distance each time.' 'OK,' says the engineer, 'what's so bad about that?' The mathematician replies, 'That's terrible. No matter how many times we did it, we'd never reach one another.' To which the engineer says, 'Who cares? You'd get close enough for all practical purposes.'"

Is that what you mean by practical?

ka5ysy wrote:

deilenberger wrote: - headed west to a Ducati open house at my dealer (they are BMW, Duc, Victory, Triumph)

DUC GIRL PHOTOS ?????

Just one of me and 3 of the girls.. Haven't pulled it off the camera yet, but I suspect I ruin the photo.

One salesman said Ducati said "The models are at your disposal - they'll do anything you want them to do.."

And again - that was proof that a dirty mind is a constant pleasure..

Just one of me and 3 of the girls.. Haven't pulled it off the camera yet, but I suspect I ruin the photo.

Photoshop Dude !

One salesman said Ducati said "The models are at your disposal - they'll do anything you want them to do.."

And again - that was proof that a dirty mind is a constant pleasure..

Reminds me of Friday at Hooters, where they are doing a breast cancer awareness promo where you purchase a cardboard doohickie that you can put your name on and stick on the wall. Our girl comes to the table and says "Would you like to see my Ta-Ta's?"

There was an immediate silence at the table as all considered this offer.


Turns out that ta-ta's were what they were calling the cardboard things.



God, I love Fridays at Hooters with the gang

NeilS wrote:

vielzebub wrote:Like BMW's the girls would have to be both beautiful and practical, so...who would that be exactly?

"A college student, an engineering major, comes back to his room and finds his roommate, a math major, looking very depressed. 'Hey, man,' he asks, 'What's wrong?' His roommate replies, 'My girlfriend suggested we play a game. She'd stand at one end of the quad, and I'd stand at the other end. Then we'd walk toward each other, so we're only half the distance apart. And then we'd repeat the process, halving the distance each time.' 'OK,' says the engineer, 'what's so bad about that?' The mathematician replies, 'That's terrible. No matter how many times we did it, we'd never reach one another.' To which the engineer says, 'Who cares? You'd get close enough for all practical purposes.'"

Is that what you mean by practical?

Originally, no, but upon further reflection.....ABSOLUTELY.

Thanks for the laugh...

NeilS wrote:OTOH, I've been stuck in stop and go traffic, in 90+ degree weather, and the oil temperature did not go to the top of the gauge. I can understand loss of oil pressure at idle when the oil is hot, especially with lighter-than-normal oil (do we KNOW that the break-in oil is lighter than normal?), but I'm wondering if you have a problem with your cooling thermostat or the calibration of the gauge.

Ditto. The highest oil level I've seen on the multifunction display is two bars from max, including an hour of stop-and-go in downtown D.C., where air temperature was 97 degrees. I'm at 699 miles to date on a bike that still has break-in oil. (Doing the 600-mile service this week.) I've commuted more than half those miles, usually stop-and-go, and have taken several 2-hour+ day trips. Might have gotten the rev. counter above 4K a few times. More often than not, though, the oil level mid-point on the indicator.