Boxer Engine history

[roamingbeemer]

Hello, I just got a 2011 GS Adventure and I am trying to learn the technical changes in the boxer engine since the 1970s. All the terms of Airhead, Oilhead etc are confusing for me at this point. I know the new boxer has chain driven dual cams now but I want to learn about the past engines as well. Does anyone know a link or a resource for the info. I also have a F650gs which I have kept as a working bike. Thanks in advance for any information.

[marc]

Short version:

Starting in late 1969 BMW came out with the type 247 engine, aka AIRHEAD. This engine moved the cam below the crank from above the crank where it was found on earlier engines.

1993 saw the introduction of the R1100RS, the first bike using the then new OILHEAD engine with fuel injection and 4 valves/cylinder. The cam was moved to mid head with the valves actuated by rockers on very short pushrods.

In 2004 the HEXHEAD engine came on the new R1200GS. This engine was a bit larger, a bit more horsepower, and contained a counter balance shaft. The name comes from the rough shape of the valve cover.

The 2010 models changed to an overhead cam. An earlier version of the overhead cam was found on the limited production HP2 Sport in 2007.

Rumored: 2013 model GS will be water cooled. Spy photos of a camouflaged version of that bike have been published various places.

This page: BMW Motorcycle Models has lots of info on the various bikes BMW has made over the years.

[roamingbeemer]

That is a perfect short version. This appears to be a very good forum with very professional responders. I am impressed. I normally do not get involved with forums because there are always a few who ruin it.
I heard about a redesigned engine but did not know if may be the 2013 model. I wonder if there will be a mad rush to purchase the first ones with big back orders like the 1600GT. I like the even temperatures in a liquid cooled engine to prevent piston buffing when a cylinder cools and contracts faster than the piston. I am sure this is not a big problem with the 1200 but I do consider it when coasting down long hills and I will add some throttle occasionally.

Thank you again for the information. I am looking forward to many hours of enjoyment on the 1200 in addition to my F650 twin which has been flawless so far at 11,000 miles. (touching wood)