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

Has there ever been any talk of a water cooled boxer? I think that this would be a great idea for modernizing them. I know that BMW's history inclines them towards an air cooled engine, but what do you think?

I've wondered that myself. My previous bike was a K75 and although I *definitely* like my new R better, if it was liquid cooled it would be perfect!

I always get corcerned when I'm sitting in traffic on my R. The fact that it *doesn't even have* a temperature guage adds to my angst! It's as if the BMW designers/engineers decided that since the motor is going to get so damn hot anyway, they would rather that we not even know!

Liquid cooling is the only thing that I miss about my K..... OK, I also miss the self cancelling turn signals, the little read-out that would tell me what gear I was in and the built-in handle for pulling the bike up onto its center stand.

But THAT'S IT.

Harry wrote:I always get corcerned when I'm sitting in traffic on my R.

It doesn't so much need water cooling as it needs fans on the oil coolers. I'd rather not have the weight and complexity of water cooling.

"It doesn't so much need water cooling as it needs fans on the oil coolers. I'd rather not have the weight and complexity of water cooling."

That seems like the perfect compromise and a easy modification for our German engineers.

So why not? Is it merely tradition??

Harry wrote: So why not? Is it merely tradition??

Cheapness, I'd say. They have fans on the Authority (Police) models as if they are the only ones subject to extended idling. BMW's engineers should have been forced to sit with me on I-75 north of Atlanta this week-end as the APAC World Pavers worked their magic on three of the four northbound lanes.

I am working on a fan adaptation to my oil coolers since BMW could not see to offer it as standard.

Lee

I think it is definitely a possibility. Porsche resorted to water cooling for their boxer engines. My vague recollection and hazy understanding is that in order to keep getting more horsepower out of an oil/air cooled boxer engine, and also comply with strict German noise laws, you eventually reach a point where you have to implement a more efficient cooling system.

Water cooling means that the engine can be made to finer tolerances (less thermal range) which gives more power. Water jackets also quieten the engine some.
It would be quite a simple job to replace the aircooled barrels with water jacket ones. Just a case of finding a home for a radiator and a pump.

VW did it on the last generation of the Beetle Van

single650 wrote:VW did it on the last generation of the Beetle Van

I had a VW water-boxer Vanagon. What a disaster! Personally, I'd hate to see the oilheads gain weight and complexity, and I personally don't need/want more power. The new K1200R, S, and GT should fit the bill for people who want to live life at its water-cooled limits. The historic character of a BMW was a lightweight, uncomplicated motorcycle that was comfortable and dependable and which would last a long time. They weren't the high power choice. It's OK for BMW to build computer controlled, high technology rockets for that segment of the market that wants such, but every model in the line-up doesn't have to be that way. It's OK to save one model for the people who STILL want a lightweight uncomplicated motorcycle that is built not for the next quarter-mile, but for the next quarter-million.

domekrome wrote:Has there ever been any talk of a water cooled boxer? I think that this would be a great idea for modernizing them. I know that BMW's history inclines them towards an air cooled engine, but what do you think?

Possibly... but I'd prefer two things over water-cooling the Boxer: an oil-temp gauge and oil cooler fans.

Capt. Blackadder wrote:... but I'd prefer two things over water-cooling the Boxer: an oil-temp gauge and oil cooler fans.

I haven't cracked the cooler fan nut yet, but the oil temperature gauge thing is easy. If you have an alternative source of the correct time, you can replace the clock with your choice of oil temperature gauges. A 2-1/16" gage fits nicely. There are two easy alternatives for the temperature signal.

1) Cut into the infeed line to the right oil cooler with a tee fitting. The run of the tee contains barb fittings for the oil line. The side of the tee contains the temp sensor for the gauge.

2) There is a blind hole behind the front cover that can be threaded 1/8" npt and the temp sensor can be bottomed out against the front of the motor. Since it is a dry hole, use oil on the threads instead of teflon tape. This doesn't directly read the oil temperature, but it does read engine temperature well and it varies directly with oil temperature.

I chose the tee fitting approach and I installed the gauge in my fairing instead of replacing the clock.

I used to have an RT, which has way more plastic covering the engine. I now live in WA state, but I only recently moved here. I used to live in southern Louisiana. The RT, and the R11R that I had, never ran into a cooling problem. The RT has the temp gauge, no cooling fans. Many on the RT db added cooling fans, most were the same ones used on the RT-P's. All that added the fans said it didn't really offer much in the way of extra cooling. The fans seemed to work better once the bike was moving, which is not needed once the bike is moving. They all recommended not wasting the money. I never had the bike (RT) come close to over-heating. It will run up on a hot, balmy, humid day sitting in traffic, but it never over-heated, and it always cooled right back down as soon as I was moving again. The R didn't have a temp gauge, but having the RT at the same time offered some insight to where the temp was. I never ever gave it a second thought. As long as there was any air movement, there was no need to worry.
If you sit still in traffic long enough to over-heat these engines, you need to find another route or just turn it off.

What we need is for the US to pass a lane splitting law ala California so that you poor people don't have to worry about getting stuck in traffic.

Lane splitting - bad. You Kalifornicators are lucky (in a way) that motorcycles are ridden 12mos of the year - drivers are used to seeing MCs all the time. This is not so nearly everywhere else. This would make lane-splitting a VERY risky exercise. I wouldn't do it even if it were legal - it justs pisses cagers off when you go to the head of the line....

Water cooled Boxer? Never. Oil cooler fans? I wonder if the new R1200R's single, HUGE oil cooler has fans attched to it. We'll see.

I do not recomend lane splitting in the Northeast. A certain % of people in cars here are not fully put together mentally.

Once I used the shoulder of the road during a multi-mile backup. I sat there for 15 minutes, and watched about 5 motorcycles go by me on the shoulder, so I figured what the hell my bike is cooking.

It was one of those half shoulders a car could not use.

The cagers went nuts! Screaming foul language and calling me a 'cheater'.
I started accellerating as it appeared things were about to be thrown at me.

sjbmw wrote:I do not recomend lane splitting in the Northeast. A certain % of people in cars here are not fully put together mentally.

Surely you do not mean New Jersey? The drivers here are extremely polite, patient, and courteous. In fact, many drivers here have given me the "You are #1" sign with their, uh, middle finger. Of course, they had to put down their cell phone and cigarette to salute me in this respectful manner.

rdsmith3 wrote:Of course, they had to put down their cell phone and cigarette to salute me in this respectful manner.

Were you close enough to catch the...

"So whassamatta witchoo? You frickin' special er sumptin?"

Lee - recovering ex-Jersey resident

beemerphile wrote:

rdsmith3 wrote:Of course, they had to put down their cell phone and cigarette to salute me in this respectful manner.

Were you close enough to catch the...

"So whassamatta witchoo? You frickin' special er sumptin?"

Lee - recovering ex-Jersey resident

I couldn't hear everything they said, but I think it was "(something) YOU!"

A water cooled, Dual OverHead Cam boxer can be as simple as changing the barrels and cylinderheads and integrating a radiator. The water pump can be driven off the camshaft like the new K1200 engine. A nowadays common shim under bucket DOHC design would also allow 130+ HP with a 15,000+ mile service interval. BMW would never do that . . . they'd make an entirely new engine.

Water cooling doesn't have to be ugly or change the look of the bike. This pic of my water cooled VX-800 that I traded in is proof.

The tall narrow radiator was hidden between the front downtubes. Because of the external cylinder finning, the fan only very rarely came on.

sjbmw wrote:I do not recomend lane splitting in the Northeast. A certain % of people in cars here are not fully put together mentally.

Once I used the shoulder of the road during a multi-mile backup. I sat there for 15 minutes, and watched about 5 motorcycles go by me on the shoulder, so I figured what the hell my bike is cooking. It was one of those half shoulders a car could not use. The cagers went nuts! Screaming foul language and calling me a 'cheater'. I started accellerating as it appeared things were about to be thrown at me.

Had the same experience in Pennsylvania, going from Rt202 onto the Pennsylvania Turnpike entrance ramp in King of Prussia when traffic was backed up for miles due to construction. I took to the shoulder on my white '87 K100RS. (figured the cagers would think I was a motor cop responding to an accident---- )

Wow, was I mistaken----cagers went ballistic, horn blowing, yelling and screaming at me.

However, in Arizona, a motorcyclist attempting to dodge a traffic tie up seems to tolerated! On several occasions I've been allowed to cruise the shoulder of the road during a traffic tie up, then allowed to just slip right in ahead of the pack.

Is it possible that some motorists have sympathy for bikers when air temperatures reach 100 degrees in Arizona??

Ed..