S&S Cycle 635G Gear Drive Camshaft Set

• Comes with camshafts and inner gears, this kit is designed for those who are replacing or upgrading an engine already equipped with S&S Cycle gear drive cams, and will be reusing the existing outer gears

• Installation kit 434-207 is not included but is recommended

• Fuel injection tuning required

• Pinion shaft run-out must be checked before installing S&S Cycle gear drive cams

• A hydraulic press and other professional tools are required to install S&S Cycle gear drive cams

• Additionally, material must be removed from the inner surface of the stock gear cover

• The stock crankcase may require clearancing for S&S Cycle .625″, .640″, and .675″ lift cams

• S&S Cycle recommends that gear drive cams be installed by a professional mechanic

• Due to the inherent characteristics of gear drives, you may experience more valve train noise with gear driven cams

• Oversized and undersized gears are available to help achieve correct gear lash

• We have found that with 160 lb. of valve seat force, the S&S Cycle gear drive cams will perform well up to 6200 rpm

• If higher rpm is anticipated, valve springs that provide higher seat force should be used

• Camshafts that exceed the limits of the stock valve springs require the use of special high lift springs

• Most S&S cams have higher lift than stock and are designed to take advantage of the extra flow of ported stock heads or S&S Super Stock heads

• Due to the high lift of these cams, S&S Cycle adjustable pushrods are recommended

• To get the best performance from a performance cam installation, a high flow intake and exhaust system is also recommended

• Kit contains cams, gear cover gasket, cam bearings, and instructions

• 2005-up stock valve springs will handle camshafts with lift up to 0.585″

• If a camshaft with higher lift is installed, high performance valve springs capable of handling a greater lift must be used

• Cams with over 0.585″ of lift will cause interference between the valve spring top collar and the valve seal with stock cylinder heads

• 635 camshafts are High lift cams for modified engines with 106″ or greater displacement and compression ratios between 10.0:1 and 11.0:1

• Works well with stock, un-ported heads, but S&S CNC ported heads are recommended. Best power from 3000-6000 rpm

• This is not a bolt-in cam set. High-lift springs and clearance checks are required