Better Boxers

Better Boxers

Three BMW flat-Twins get dohc and more power

BMW's iconic Boxer Twin is in for a meaningful performance upgrade. Most of the BMW faithful consider the present sihc 1200 more than adequate, but BMW loves to engineer and had developed a rather sophisticated head design that finally allowed the use of dohc while retaining the elegant rear-facing inlet, forward-facing exhaust.

New dohc radial-valve heads were used in highly tuned R1200S endurance racers and then applied to the expensive, limited-production HP2 Sport, which became the mostpowerful production Boxer ever. Now those same heads are being fitted to the 1200cc Boxer that powers the 2010 R1200GS, R1200GS Adventure and R1200RT. All three models had a 105-hp version of the Boxer, and now they have been reinvigorated to 110 hp with the rev ceiling raised to 8500 rpm (up from 8000). Larger-diameter valves, increased lift and bigger, 50mm throttle bodies contribute to the added power, as well. These first large-production models to receive the new heads are otherwise substantially unchanged.—Bruno dePrato