Yes, even with the boxer engine, it must have been a first time. The example pictured above was by Karl Benz, who experimented with multi-cylinder engines since 1897. Different from Gottlieb Daimler he is not focused on the V-engine, but on the boxer engine, after he already constructed a two-cylinder in-line engine with counter-rotating pistons. It is the logical consequence, if one wants to connect two cylinders with good mass balancing and constant ignition.
It is surprising how close constructive this engine his numerous successors. Thanks to the open crank mechanism can be well recognized one of the two connecting rods on the crankshaft with no center bearing. The cylinders face each other shifted opposite to each other only by a cranking. They are lubricated by glass boxes which must be refilled at regular short intervals. That is not ecologically friendly friendly, because you can work out where the oil remains.
Photographed from the right side, this engine us even reveals the typical valve train for the time. But let's start with themost conspicuous components, the steam collectors above the cylinders. A circulating cooling system does not yet exist. Thecooling is reached by evaporation (and condensation) of water. Front of the crankshaft is concealed the 2:1 translationfor ignition and valve control. Flanged sideways at the cylinders is visible on each side the valve train with the suction nozzle for the installation of the carburetor equipment and the electric sparks. The intake valves, each outer, will be opened by the underpressure created in the engine. On the opposite side the (stationary) exhaust valves are driven by a lobe in the middle. The more significantly developed buzzer ignition by Benz works with a contact in the middle, and very similar to the later used for many decades. Daimler and Maybach engines operate at the time still with glow-tube ignition.
The engine is thus innovative, not only due to its construction, but also because of the other components. Also by the perfect balancing of moments achieve later vehicles rotational speeds above 1000 rpm, for the time still completely unusual. This is associated with correspondingly higher performance. There remains only the question, which is the real 'Contra Engine' this or that of 1897 ... 11/06