One unique motorcycle, the Honda CBX
In the wonderful world of superbikes, a high revving inline four cylinder engine is commonplace and almost the default layout and configuration for high performance motorcycles, but as we have seen many times, there are rare instances in which engineers get away with challenging the norm.
Everything about this 2 wheeled contraption seems rather tame and normal, until you get to the engine. The unit powering this bike is as anomalous as a Wankel swapped Prius, borderline impossible.
The Honda CBX was made from 1978 to 1982.
A 1047 cc 24 valve, twin cam, inline six cylinder sporting 6 individual carburetors, which delivered a healthy 100 horsepower. Not only is this the first Honda motorcycle to feature a six cylinder engine, it’s only the second one in all of bike history to feature such a strange power plant. The Benelli 750 Sei was the first inline six motorcycle.
The engine choice for the Honda CBX seems odd at first, but the characteristics of a dual cam inline six actually meet most of the criteria for what makes a good motorcycle engine.
An inline six is inherently balanced, which means it has smooth and consistent power delivery, it can also rev higher, since the reciprocating mass inside the engine is balanced, meaning the pistons cancel out the moment of inertia of each other. The main disadvantage comes when it’s time to package the absurdly long block transversely into a motorcycle frame. The result is a bike with a fraction of engine sticking from either side; even then, Honda engineers deemed the increase in frontal area negligible, as the 2 extra cylinders didn’t occupy more frontal area than the rider’s legs would.
Like the engineering behind it, the exhaust note the 6 cylinder Honda CBX produces is exquisite. With a musical exuberance rivaled only by vintage Formula 1 engines.
Watch the video below.