Rocketing the KTM RC 8C off the line is a ultra-potent, lightweight and compact 128 hp 889 cc LC8c engine. If that sounds familiar, it’s the same, celebrated powerplant found in the KTM 890 DUKE R, but with more focus on more and drive out of corners. The benefit of using a production engine is easy maintenance and parts availability, without sacrificing on performance.
The KTM RC 8C’s powerplant features high-pressure cast aluminum, horizontally split crankcases. This allows for reduced wall thickness for weight optimization. The open deck cylinders are integrated into the crankcase for a more compact assembly.
Thanks to a set of forged box pistons featuring three piston rings each and a bronze conrod bearing with a DLC coated piston pin, the KTM RC 8C revs willingly and delivers torque throughout the range. Also, because the pistons make use of a box construction, their weight is minimized despite the large bore.
The 8 valve DOHC cylinder head contains twin chain driven camshafts, a spark plug per cylinder and camshafts that have been assembled rather than forged, making them lightweight. The steel valves - 37mm intake and 30 mm exhaust - are opened by DLC coated finger followers, for smoother operation and the timing chain is tensioned by a hydraulic chain tension adjuster. It's smooth too, thanks to a secondary balancer shaft which is actuated by the exhaust camshaft, between the two camshafts.
The electronic fuel injection system on the KTM RC 8C features sensors in each throttle body which measure the manifold pressure and adjust the mixture accordingly per cylinder. Two dedicated engine mappings are available, wet and dry, that can be easily selected from the handlebar.
Unique and developed specifically for the KTM RC 8C, the large airbox which occupies the entire "tank space" between the rider's legs is fed via a ram air intake channeled from the front fairing, while also featuring a dedicated air filter from Twin Air.
Lightweight and pressure lubricated, the slipper clutch on the KTM RC 8C features improved cooling and reduced friction over other units. The slipper clutch opens when the engine back-torque becomes too high, it also assists when you open up the throttle. The former prevents destabilizing rear wheel chatter when braking sharply or decelerating, while the latter reduces the hand force required for changing gear, allowing the clutch to be controlled with the little finger - saving you energy when riding. The clutch is also cable activated for further weight reduction.
Ensuring optimal lubrication, the KTM RC 8C employs a semi-dry sump system, whereby oil is actively pumped out of the crankcase, clutch housing, and transmission. This ensures that oil does not unnecessarily flow through the engine, reducing friction losses. The oil sump is integrated into the oil pump housing, together with two pumps and a pressure regulating valve.
Providing the bark to the KTM RC 8C's bite, is a bespoke stainless steel racing exhaust with an Akrapovic titanium muffler with a carbon end cap. Equipped with a decibel killer designed to tame the twin-cylinder symphony from 105 to 103 dBA, but should local track requirements dictate it, an alternative 98 dBA muffler can be ordered separately.