BMW R-Series Gets Revised Motor with DOHC

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The rumors appear to be true, and the BMW R series is getting an update to its motor for 2010. Maintaining its existing 1,170cc displacement, the most notable change to BMW’s flat boxer motor is a dual-overhead camshaft (DOHC) cylinder head setup, which was previously only seen on the HP2 Sport.

With the bore and stroke staying the same for 2010, the R lineup will continue to use the same 101 x 73mm cylinders, making a total of 1,170cc’s. The real changes and improvements come from the new cylinder head design. The DOHC design features two chain-driven camshafts, with each camshaft controlling both an intake and exhaust valve in the radial four-valve head.

While the cylinder hasn’t changed, the valves have, and will come with an increased diameter size (intake: 1.42-1.54 inches;  exhaust: 1.22-1.30 inches). The valves will also have an increased lift, while maintaining the same 12:1 compression ratio. Lastly, the combustion chamber shape has been modified, and now employees the use of red-designed cast-aluminum pistons, which will also make better use of the redesigned air intake manifolds.

All of this means a more powerful and higher-revving motor. Expect to see 110hp @ 7750 rpm (+5hp increase) at the crank, and peak torque at 88lb•ft  @ 6000 rpm (+3lb•ft). The motor’s redline has also been increased by 500rpm, which raises it to 8,500 rpm’s.

The new Boxer motor is the core upgrade to the three 2010 R-series machines announced by BMW: the 2010 BMW R1200GS, 2010 BMW R1200GS Adventure, and 2010 BMW R1200RT.

Source: BMW

Jensen Beeler

Despite his best efforts, Jensen is called one of the most influential bloggers in the motorcycle industry, and sometimes consults for motorcycle companies, whether they've solicited his expertise or not.