Originally Posted by simoneau
I don't thimk anyone has mentioned the absence of an oil pan. This is a drysump engine, thus lowering the engine in the chassis by 3-4 inches. The extra room in the cam drive gallery of the heads could be for variable valve timing apparatus which was mentioned in the BMW Motorcycle Magazine interview about the new boxer about a year ago. Notice the watercooling passages bypass the cylinders and only supply water cooling for the heads, thus air/oil would still provide cooling for the cylinder walls and the pistons. As mentioned by others here the lower front portion of the crankcase should provide for a stator and alternator windings possibly imbalanced to provide part of the balance shaft of the engine. With the wet clutch we finally have a single oil crancase for the engine, transmission and alternator with the subsequent minimum number of shaft oil seals involved similiar to any modern engine/transmission now available. Reliability should likely rise in accordance. My $.02.
Lowering the CG is a huge benefit if what you described is true.
The other point I'm curious about is 'if' the water cooling is only for the heads, does that mean a smaller water circuit (hence less mass/volume added)? It sounds like its designed to eliminate redundant mass (the common oil volume for one example), and with newer casting techniques the overall engine weight may be comparable to the current model. (Ducati 1098 and 848 castings as one example of thinner wall castings and weight being minimized).
I have to say that I think the existing engine is under-stressed. Meaning that it's robust enough for future power increases as witnessed in the HP2s and R1200S. I really don't want to see the added complexity of a water circuit and all the BS that goes with it.
BUT. One thing I loathe on the existing boxer is the resonating feeling of that engine at 70-85 mph. If this architecture has better power flexibility, better (lower) CG and buttery smooth power at highway speeds, it may not be all bad.
I still think the HP2 MM and HP2e should have a place in the lineup though.