W&W Cycles

S&S KN-Series for 1936-47 Big Twins

The KN-Series engines are very close in appearance to a stock knucklehead engine. Numerous reforms enhance power, engine life, and reliability. Aside from the much larger 93” displacement, the main improvement in design is the 1958-65 style flywheel assembly, which uses a splined sprocket shaft and a Timken sprocket shaft bearing on the drive side. Although this necessitates the use of a 1954-65 style inner tin primary cover and primary chain sprocket, the increased flywheel stability, strenght, and power handling capacity are worth a slight departure from stock. Flathead Power rocker arm cover “tins” are another modern improvement. The lower covers are actually made from die-cast aluminum, and instead of being held in place by the valve guide, they are held down by valve spring pressure. A special gasket on the bottom of the lower “tin” provides a positive seal, and is much easier to service if needed, since the valve guides do not have to be pressed. Also instead of the steel brazed-in hard oil return lines used on stock tins, S&S has improved the design of the oil line for better reliability and easier assembly and maintenance.

The KN93 engines offering consists of 93” engine, either with crankcases for early style chassis, primary and transmissions, or with alternator/generator style cases for use with 1970 and later primary covers and late style transmissions. Flathead Power KN-Series engines come completely assembled and ready to run with a electronic S&S Super Stock ignition system and Super E carburetor.

For further informations please contact our sales team or your trusted dealer/customizer.