It is not your grandfather's BMW anymore. I still like airheads, but I'd buy this in a second if I could sell my kids for a good price
The HP2 Sport keep the 1170cc (101.0 x 73.0mm bore x stroke), air-and-oil-cooled, opposed Twin (“Boxer”) engine of the R 1200 S, but the engine has been fitted with chain-driven, double overhead cams in place of the High Cam and push rod configuration of the R 1200 S.
Each of the horizontal camshafts actuates one 39.0mm (up from 36mm) intake and one 33mm (up from 31mm) exhaust valve via a “drag lever.” Shims under the “drag lever” are used to adjust valve clearance. The four valves in each cylinder head are arranged in a radial fashion. The new cylinder heads also get revised intake porting and carbon covers with replaceable, hard plastic slider/protectors. New forged pistons and new connecting rods are used in the HP2 Sport, but compression ratio remains 12.5:1. While the use of higher-octane fuel is required, only a single spark plug is needed for ignition for each cylinder.
Dual throttle bodies measure 52mm and are controlled by BMW’s own closed-loop, BMS-K fuel injection/engine control unit (ECU). A new exhaust system routes the header pipes underneath the engine to a catalytic converter and then up under the self-supporting carbon tail section past an ECU-controlled butterfly valve and on to a dual-outlet stainless steel muffler. Dual oil coolers (one directly behind the other) located behind the two, kidney-shaped intakes in the nose keep oil temperatures in check, which together with the new valve train contributes to a new engine redline, 9500 rpm. Peak horsepower output is claimed to be 128 at 8750 rpm, while peak torque is 84.8 lbs.-ft. at 6000 rpm (up from 122 bhp @ 8250 rpm and 83.0 lbs.-ft. of torque @ 6800 rpm on the R 1200 S).
Ask not what the wanker can do for you, but what you can do for your wanker!