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Events: On Saturday, June 18th at 1:00 p.m., Iron Horse will host a Tire Changing Seminar. Learn the correct way to remove and replace your tires without damaging hubs and brake rotors. You can also see one of our technicians remove, replace and balance a tire using shop equipment. Light refreshments.
It
was nice seeing so many familiar faces at Heber. We had a great time
and I hope you did, too. We just got our K1200R, and I am in lust.
BWM is finally making the bikes I have dreamt about. I love riding
my boxer cup at the track, but the new K12R may take its place. Many
of you already know that the HP2
(BMW’s new enduro) is making waves in the enduro world. Did you
know that in one of Europe’s top enduro events (Erzberg Rodeo Race) the
HP2 took 1st, 3rd and 5th! In keeping with a GS oriented theme, we
will be sponsoring the Arizona Adventure Rally in early November in
conjunction with RawHyde
Adventures. I hope my HP2 comes in before the Rally!
Jennifer says hello, but Ella (# 2 daughter) still does not sleep!
Until next month- Ride safe- John
Let’s Get Naked!
Now that we’ve got your attention, take a look at the new
K1200R. The most powerful naked bike ever has arrived in the Iron Horse Motorcycles showroom, and we are more than pleased with what we see. Come have a look at BMW’s newest: a 163 bhp, unfaired bike that is sure to turn heads and cause a commotion.
For those not of the hooligan persuasion, the K1200R’s more civilized cousin, the
R1200ST, is here in the
showroom and available for demo rides now. Whether you are looking for something to tear up the asphalt as you snarl past a sport bike rider with your front wheel held high (while obeying all applicable traffic laws and safety recommendations, of course), or something to glide through the corners with surgical precision and touring comfort, it has arrived.
Techniche International -- Climate Control Apparel
Sport Vest
Evaporative Cooling Sport Vests are easy to use and provide hours of cooling relief.
Simply submerse the entire vest in water for 1 - 3 minutes, or until it reaches the desired level of hydration. Gently wring out excess water and it's ready to wear.
These Evaporative Cooling Vests will provide many hours of cool relief and can be re-activated by re-submersing the garment in water. Sport Vests are lined with proprietary Polymer Embedded Fabric and include a water repellant nylon to minimize wetness on the interior of the garment. The outside fabric is a durable nylon and each vest fastens in the front with a sport zipper. To accommodate various body shapes, Evaporative Cooling Sport Vests feature an articulating gusset under the arm.
Silver Function T-Shirt
The Silver Function fiber is an innovative combination of textile and silver that offers
good moisture transport, thermal regulation and a pleasant anti-static feel without the
odor retention problems of other wicking fabrics. Blue/Gray, Orange, Rust/Gray,
Gray/Green. Unisex sizing XS to XXXL.
BMW Motorcycle Cooling Systems: Part 4, BMW Oilhead Cooling
By John Heibler, Iron Horse Service
Summary of Part 3, Liquid Cooling: BMW Liquid Cooled Engines. Liquid cooled engines in general are more complex because of the additional components, but on the other hand, cooling of the overall engine is more uniform and better controlled than an air-cooled engine. Every cooling method therefore has its advantages and disadvantages, its all part of the design goals as set forth by the manufacturer and desired operating conditions of the engine itself.
CAUTION:
Exercise Extreme Caution when working around Cooling Systems and Hot Engines with Hot Exhaust Systems. Severe Burns can result by touching the above mentioned components/systems. Always wear protective gear for face/body/hand protection.
Liquids are Better Cooling Mediums – We can Shiver in the Pool even on a Hot Day
Relaxing in the pool allows us to quickly cool off. Water molecules are densely distributed and therefore transfer temperature (hot or cold) better than the more loosely distributed gas molecules
which make up air.
Tidbit: Maserati Cars in the early eighties (which used a Twin-turbo engine, the
Biturbo) used water (from the cooling system) through a heat exchanger to cool off the hot compressed air from the turbocharger instead of using air. It was just more effective.
Oil Cooling...and Air Cooling
The Oil Cooling method in combination with Air Cooling has been with BMW Motorcycles for a number of years. The modern boxer oilhead incorporates both techniques to cool the engine. How is this done? We'll see later in this article.
Advantages:
- Oil or any “liquid” transfers or carries heat away much better than air, because the molecules are closer together.
- In the case of the BMW Oilheads, oil is used to lubricate the engine internals and additionally cool off the exhaust side of the cylinder head at the same time.
Disadvantages:
- Added complexity of additional extra hoses, oil coolers, oil pumps, oil pump drives, additional oil passages and extra machining work, etc., to the design of the engine. This also increases costs and labor to the overall production cost of the bike.
- Added weight (components/oil etc.) versus an air cooled engine.
BMW R Models “Oil Heads” as of 1995:
In February 1989, BMW decided to further update the boxer style engine. Even though the K series was seen as quite advanced with its technology, many customers still wanted the classic boxer engine.
Racing Heritage of the Boxer. More Power...More Heat
In America, the racing heritage started with Butler & Smith, Inc. They campaigned a /5 and a Grand Prix bike many years before the super bike racing of the 70's and their AMA Super Bike championship win in
1976. Boxer competition was well-established in Europe, with many enthusiasts like Krauser and
Fallert. Most bikes built by those diehard boxer enthusiasts produced from approx. 80 DIN (Deutsche Industrie Norm) horsepower to approx. 115 DIN horsepower, but with some degree of road manners for the average rider. There were BMW boxer bikes built for racing long distance races in Europe such as Bol d’ Or and the Isle of Man. No doubt that it was the sheer enthusiasm and love for the boxer engine that spurred BMW not abandon its first bike design. Helmut
Daehne, a tire test rider for Metzeler tires had much prior success riding an airhead /5 model in many European events including the Isle Of Man
TT. As time went on, he managed to reel in the same success at various European races with a R90S, even running a race model with a 1,000cc engine. While racing both a /5 and later the R90S, he managed many finishes between 5th and 7th place or better against rival Triumph and Norton models in the same race class. Not bad for a “Touring Bike”,
after being labeled as such by the trade press in those days.
Tidbit: Helmut Daehne was known for his smoothness while riding the race bikes, even if his race bike was down on horsepower, he did manage some really great finishes at the Isle of Man and other races. Smoothness in riding a BMW motorcycle can bring its rewards, especially since today’s models
have much more technically advanced tires, suspension, frame design, etc. As he proved, practice makes perfect.
So just as with the /5 series, BMW decided to design a jewel of a two cylinder engine, but never, of course, to abandon the original boxer engine design, set forth in 1923 with the R32. Certainly, there were priorities -- an engine design that would be adaptable to many different models, have reasonable production costs and meet any future emission requirements. So the engineers went to work, certainly a liquid cooled two cylinder engine would be great for emissions, but there had to be room for the Telelever front suspension system, so the
water cooling idea was nixed. The engine had to be quite rigid because it was to be a load bearing component. Engine crankcase rigidity would also be good for noise emissions (less harmonic emissions) and would allow the engine crankcase to be split vertically.
The new R-series engine was envisioned to be just as powerful as the first K series bikes. In
other
words, approx. 90 horsepower and even
a bit more torque…Wow! This was accomplished using 4 valve heads, meaning 2 intake valves and 2 exhaust valves. This arrangement allows much better engine breathing at higher rpm. The air/gas mixture flows into and out of the cylinder head more effectively since there is a larger overall combined valve area. This can be enhanced with a properly tuned intake and exhaust system, which can boost low end power, as well.
But there was a problem… a classic 4 valve head makes more power and runs hotter. The valves are close together and there is less cylinder head area to
dissipate the heat from the valve seat area into the cylinder head fast enough. Also, in order to help the catalytic converter come up to operating temperature quicker the Motronic control module retards the ignition spark, thus causing a large exhaust flame within the exhaust port and out into the header pipe. This along with the extra horsepower required the use of oil as a medium
to transfer the extra heat and keep the engine from overheating. Part of the remedy included using exhaust valves
filled with sodium salts (as used in turbo-charged engines) which become liquid when the exhaust valves are at operating temperatures. These valves can transfer heat more effectively into the valve guides.
A 5-valve cylinder head runs even hotter. Thus late model cars circulate the liquid coolant for a period of time after the ignition is turned off, to prevent overheating of the cylinder head.
Tidbit: Exhaust valves actually glow cherry red while the engine is running. The color of the exhaust valve (when cold) is actually a much better indicator of fuel mixture than the color of the spark plug.
So, now we've got more power and torque… but how do we get rid of the extra heat??
In a liquid cooled engine it is done by routing more coolant via extra passages around the exhaust port area of the cylinder head.
But how do we get rid of the extra heat without the use of a water/ethyl coolant and without adding more cooling fins??
It is the classic problem as seen before, remember??
Using Something Hot to get Rid of That Extra Heat
Since there was oil in the engine anyway, it was decided to use this as a medium to transfer the heat away from the very hot area around the two exhaust valves in each cylinder head. This extra heat could also be used to warm the engine oil after a cold start,
and yet the extra heat could be
dissipated via oil coolers, which were thermostatically controlled. Additionally, if you inspect the front of the oilhead cylinder, you can see an extra air passage to allow cool air to flow to the hot area between the 2 exhaust valves. More importantly, oil which has just come out of the oil cooler (and is therefore at its coolest
temperature) is directed through the oil passages around the exhaust valves.
To further enhance the naturally good engine cooling of the boxer design (remember the cylinder heads and cylinders hang out there in the cool air stream), the cylinder head was rotated by 15 degrees forward.
This was done to better direct airflow to the exhaust port/exhaust valve area.
Of course, with all the need to do this for the above reasons, additional items to make it work were required:
2 oil pump rotors, oil pump drive via an auxiliary shaft, 2 oil pump pick-ups, more oil passages in both the engine crankcase, cylinder heads, oil coolers, etc.
But as you can imagine, it was worth the extra effort, for the boxer continued to live on…great!
As indicated before, when in heavy traffic for a long period of time, shut off the engine while waiting for the jam to clear. One indication that an engine is near overheating is that it will get mechanically very noisy…clatter (valves etc).
This concludes our discussion of using air, liquids and a combination of air and liquids to help engines maintain optimum operating temperatures, normally by cooling.
Now if we can only cool ourselves off as well. It looks like Jim has been covering this in the Parts section of the newsletter!
Next month we'll discuss Gasoline Octane ratings.