While BMW's passenger car division is busy trying to figure out how to get more four-cylinder engines into the U.S.-spec 3 Series, the Motorrad division is working on an inline six-cylinder for the motorcycles. Of course, the engine is billed as the lightest and most compact inline-6 the world has ever seen in a bike, and fuel consumption is said to be on par with a four-cylinder Beemer.
Of course, we're not talking about some 3-liter monstrosity, as this engine displaces jst 1,649cc, with a bore of 72mm and a stroke of 67.5mm. It's rated at 158 horsepower and 129 pound-feet of torque, and BMW notes that 92 lb-ft will be at the rider's disposal by 1,800 rpm. Compression is 12.2:1.
The engine weighs 226 pounds, and mounted transversely in the bike, it spans 22 inches across. Dry-sump oiling allows for a flat crankcase design, keeping the center of gravity as low as possible. As this is a BMW engine, lightweight materials abound. In addition to the aluminum engine block, the crankshaft, conrods and pistons are forged steel, the camshafts are composite (saving a total of 2.2 pounds); and the valve cover and clutch cover are magnesium.
Of course, this is still a big engine, so said bike is a tourer of sorts -- the K 1600 GT, or with a rear seat, the K 1600 GTL. If the S 1000 RR is the sportscar of the Motorrad lineup, the K 1600 GTL is the luxury flagship. You're certainly not meant to rev the bejesus out the inline-6, which will be limited to 8,500 rpm in series production.
To help lighten their load, both of the new bikes will have a magnesium front carrier section and an aluminum rear frame.
BMW will offer a high of amenities on the K 1600s, including an audio system with a USB input and a navigation system with real-time traffic. Most interesting, though, is the inclusion of an adaptive headlight that compensates for the bike's banking angle -- via a small electric motor that adjusts the angle of the reflector mirror inside the headlight unit.
rsholland says:
05:48 AM, 07/ 5/10
Ironic that BMW will be offering a Honda-like inline 6 (CBX and 60's-era 250 cc GP racer), while Honda offers a BMW-like boxer 6 (Gold Wing).
ed124c says:
07:31 AM, 07/ 5/10
I know nothing about motorcycles, and even less about the difficulty of putting a bike engine into a car. However, it seems to me that a compact, or subcompact PREMIUM, car could emerge using this engine.
Starting with such a light weight engine would bode well for a very light weight car. With about 150 hp and 120 ftl lb torgue, the suspension and drivetrain components would not need to be as "robust" as usual. A 2300-2400 lb car, as in the 60s and 70s, could be quite spritely.
Remember, most compact cars of the 60s and 70s had (roughly) 1.6 liter engines with 70-80 hp.
kevm14 says:
08:39 AM, 07/ 5/10
If it was ever meant for a car it will either have to be designed for it already, or modified. I'm talking about durability. You can't put a car engine into a truck and subject it to truck duty without issues. For example, GM has internal durability tests for cars and trucks. The trucks' cycle is 10x longer than cars, and as a result, the trucks run in a less hyper state of tune in order to pass the tests. It's the difference between pushing a Camaro around with 400hp or a 5200lb truck towing 6000lbs. One engine gets wrung out then gets a break, and the other is subjected to constant stress. The same would go for going from bike duty to car duty. I'm not sure there could really be a production translation here. Sure someone could build a one-off kit but aside from that, I would be very surprised.
desmolicious says:
09:33 AM, 07/ 5/10
Rsholland wrote:
"Ironic that BMW will be offering a Honda-like inline 6 (CBX and 60's-era 250 cc GP racer), while Honda offers a BMW-like boxer 6 (Gold Wing)."
BMW has never offered a boxer 6. The most they have had is a flat twin in that configuration in their R series bikes. Porsche makes the boxer 6 motor (but not for bikes).
This bike will NOT be a cruiser. The GT and GTL names describe a luxury sport touring bike, with the L being more focused on the touring side, the GT more on the sport side.
desmolicious says:
09:35 AM, 07/ 5/10
Sheesh, even your sketch shows it's not a cruiser!
rsholland says:
09:55 AM, 07/ 5/10
@desmolicious says:
"BMW has never offered a boxer 6. The most they have had is a flat twin in that configuration in their R series bikes. Porsche makes the boxer 6 motor (but not for bikes)."
Never said they made a boxer 6; BMW, for decades has been known for their boxer bike engines, which is what I'm referring to. Only in recent years have they strayed somewhat from their boxer-engined bike image.
desmolicious says:
10:24 AM, 07/ 5/10
"Only in recent years have they strayed somewhat from their boxer-engined bike image."
The 4 cylinder BMW K100 came out in 1983. So I guess recent years = 27 years ago.
;)
rsholland says:
10:33 AM, 07/ 5/10
Their first boxer motorcycle, the M2 B15 came out in 1921, so yeah, I'd say 1983 is relatively recent.
desmolicious says:
12:02 PM, 07/ 5/10
LOL
no.
rsholland says:
05:40 AM, 07/ 6/10
Since BMW has been building boxer motorcycles for 89 or so years, introducing a different engine layout 27 years ago is by my definition, a recent occurance. YMMV.
chochmastergen says:
07:44 AM, 07/ 6/10
Ed124c:
You won't see this in a car because its way too performance tuned. The materials, the machining, the compression. Its all too expensive to use this over a bigger heavier 4 cylinder.
Also, those old small cars were puttering around with 80-90 hp because they were deathtraps. They didn't have anywhere near the structural members today's cars have to have. They also didn't have hundreds of pounds of airbags, electronics, air conditioning, power steering, windows, locks.
A small light car using that engine wouldn't make sense. It would be a small barebones car, made from exotic materials. So you'd get 50mpg, pay 80k, and have no luxury.
desmolicious says:
08:45 AM, 07/ 6/10
"Since BMW has been building boxer motorcycles for 89 or so years, introducing a different engine layout 27 years ago is by my definition, a recent occurance. YMMV."
Or... since BMW has been building 4 cylinder bikes for 1/3 of its existence, it is not a recent occurrence.
p.s. thanks for removing the cruiser reference in the story.
rsholland says:
09:13 AM, 07/ 6/10
"p.s. thanks for removing the cruiser reference in the story."
??? I didn't write this story.
roadburner says:
05:50 PM, 07/ 6/10
Nice motor, but I still prefer my Speed Triple...