If we told you that there is a BMW boxer engine with desmodromic actuation valves, you would surely say that it is fake news, well no, the BMW R1 exists and it works.
When we talk about a boxer engine we talk about BMW, and when we talk about an engine with desmodromic actuation of its valves we talk about Ducati. This has been like this for decades, but what if we mix it up?
Well, the same thing happened in 1992, now thirty years ago, when BMW engineers, in search of more power, came up with the idea of putting a desmo valve actuation system on their latest evolution of the boxer engine.
The result was a prototype, a rolling test bench that would serve to develop a new generation of boxer supercars, which should also elevate the Bavarian brand in the superbike segment.
The BMW R1 was a rolling prototype to create the future Bavarian boxer superbike
To do this, they manufactured a robust aluminum double beam frame, something unprecedented in BMW at that time, they added a front Telelever system, obviously anchored to the engine, and a single-sided swingarm with cardan equipped with Paralever. And a lightweight seat support subframe and tail liners were also added.
It was finished off with three-spoke light-alloy wheels, and a Brembo braking system, with two 320mm front discs clamped by a pair of Brembo Gold four-piston calipers and a rear disc clamped by an opposed double-piston caliper.
But the important thing was the boxer engine that had nothing to do with any other Bavarian engine that was marketed.
Its basic boxer structure was maintained although the cylinder heads were worked to reduce them to the minimum expression. Even the angle and placement of the valves are designed to decrease ground clearance on inclines…
The complex was a monolithic block with an imposing appearance. The clutch was a large-diameter dry single-disc, as was usual for the brand, with the alternator and water pump placed at the front of the engine, taking advantage of the crankshaft for direct operation, without mechanical intermediaries.
Its internal dimensions were 98 x 66 mm, with a displacement of 996 cc, it was liquid cooled, with distribution controlled by double chain, and in the cylinder head it housed two camshafts and has four huge valves per cylinder.
The double timing chain thing is because it had a chain for each cylinder and another pair that joins the two camshafts of each cylinder head. In this way, the always expensive gears to synchronize the pair of camshafts of each cylinder head are dispensed with.
Its liquid-cooled boxer engine had a desmodromic system in its cylinder heads.
But everything does not end here. As I have told you, the system used to open and close the valves was desmodromic, the great surprise, as in a Ducati Panigale, saving the distances. Thus the “BMWcati” was born.
As you know, in a desmo system, the valves are not closed by the action of a spring, but rather the valve is guided at all times by a stem and a mechanism, which opens and closes it. In this way there is no possibility of valve floating at high speed. That is why the desmo system was born.
Evidently, for its supply, a modern and expensive electronic injection system was available -at that time- with one injector per cylinder.
The intake nozzles were completely vertical and took air from the airbox located in the front part of the false tank. And it had a big air intake at the front of the fairing; all this was innovative for the brand.
Finally, a pair of elaborate exhaust manifolds of generous diameter twisted under the engine to exit two into one on the upper left side, almost touching the tail.
With a displacement of 996 cc, the Munich brand sought to participate in the SBK World Championship
Looking at the bike from the side, the fact that the pair of cylinders are very high off the ground stands out. And the cylinders protruded very little from the full fairing, nothing to do with a traditional boxer.
This simply responds to the fact of seeking the maximum angle of inclination, avoiding that the boxer cylinders are an impediment. The higher, the more angle of inclination…
The result was an engine that offered around 140 hp for a weight of 165 kg, some really good data that was not enough for the Munich brand to jump into the SBK arena.
After all this waste of technology, the BMW R1 came to nothing. It did not lead to any series model and its engine was not the cradle of any modern boxer engine either. In fact, he did not even take advantage of what he had learned with liquid cooling, which would take more than a decade to arrive…
