The world has already seen spy shots of KTM’s forthcoming 990 Duke and RC990 sportbike. Unfortunately, although we could see glimpses of the new bike’s engine, we didn’t have much in the line of details. But according to Cycle World, some recent design registration filings give us a much better look at the new LC8c parallel twin engine and some of its changes. And the revisions are significant.
Differences between the two LC8c engines
The images seem to confirm that the new LC8c powerplant is getting a displacement increase. Although it retains the previous LC8c engine’s layout, that’s about it. The drawings show the new LC8c comes with entirely new castings for the block, cylinders, and head.
KTM’s new LC8c engine (L) and current LC8c engine (R) viewed from the front. Image: KTM/CFMoto
More displacement?
When the engine is viewed from the left side, it looks like the cylinders are taller than in the previous version. If this is the case, it could be that KTM is engineering some additional displacement via a longer stroke. Potentially offsetting the increase in stroke, it looks like the engine’s head is more compact than the current LC8c design. Together the two changes would likely keep both engines more or less the same overall size as the current engine.
KTM’s new LC8c engine (L) and current LC8c engine (R). Image: KTM/CFMoto
You can readily see that the cylinder castings have more external bracing. The additions could be an indicator that the new powerplant has thinner cylinder walls. The engine’s horizontal engine cases also sport changes. In the new version, you can readily see that the oil-level sight glass has been moved from a low position to a higher one in the engine’s clutch cover.
KTM’s new LC8c engine (L) and current LC8c engine (R). Image: KTM/CFMoto
Other changes
The oil pan is new and is now tapered significantly. This move could be to allow the new engine to accommodate its catalytic converter. It could also keep the exhaust system as compact as possible. In addition, the transmission has a new smaller look which could give chassis designers more latitude to position the bike’s rear shock upper mount.
The right side of KTM’s new engine. Image: KTM/CFMoto
The first bike to get the redesigned engine will likely be the KTM 990 Duke, with the RC 990 getting the new mill later. Cycle World says the new engine will be manufactured in China (as is the current engine) by the CFMoto/KTM joint venture. However, they also say that in the years to come, CFMoto may produce the engine in their own branded bikes.
