S&S, set of 640G (IOG) gear-driven camshafts

.640" valve lift. IOG = gear-driven camshafts, with internal and external drive gears. Complete kit with installation hardware, bearings and gasket.
For 95" and up models with a compression ratio of 10.5:1 to 11.5:1 (standard on S&S 124" engines).
The gear drive system is in fact a revolutionary, different and far more reliable construction. Especially in high lift/performance applications, compared with the OEM chain drive design. A gear driven camshaft is stronger and does not suffer any of the mechanical problems associated with OEM chain driven camshafts. The S&S gear drive kit will increase valve timing accuracy and therefore power, by eliminating timing chain slack and the loose fit of the stock camshaft gears. The only downside of gear drive is that you may experience a slight increase in mechanical noise; this is why the OEM uses a chain. It has no other mechanical advantage. As the chain guides and tensioner are removed, there is no longer any chance of these parts failing and damaging other parts of the engine. The S&S gear drive kit reverses the rotation of the rear camshaft, providing additional operating clearance between the cams. As a result, greater cam lifts are possible with S&S gear driven camshafts.
Note: With the exception of the 475G and 510G camshafts, adjustable pushrods (such as MCS 503573) are required to compensate for the smaller base circle of the camshaft of these cams.
Note: It may be necessary to remove material from the inner surface of the OEM gear cover before installing the S&S outer drive gears (which are required and available as 503577).
Note: The OEM beehive-type valve springs on Dyna 04-17; Softail 04-17 and Touring 04-16 models support valve lifts of up to 590" and a valve seat force of 160 lb, up to 6200RPM. Exceeding 6200RPM or lifts above 590" will require high-performance valve springs.
Note: The use of camshafts with .625", .635", .640" and .675" lifts will require grinding of the crankcases.


Specifications


Brand
S&S


Application
07-17 Softail; 06-17 Dyna; 07-16 FLT/Touring (NU)


Sales unit
Kit


Material
Steel


Packaging weight
2.722 kg


HS Code
87141090


Motorcycle family
DYNA, SOFTAIL, TOURING, TRIKE


Original name
S&S, gear drive 640G camshaft set (IOG)