S&S .640 lift cams are used in S&S T124 engines, this cam is designed to make horsepower. Intended for engines of 95 cubic inches or more with compression ratios between 10.5:1 and 11.5:1 and stock oil pumps. 3,000 - 6,000 rpm. 640G kit includes camshafts with inner gears, outer cam drive gear kit, and camshaft installation kit.
For 2006 Harley-Davidson® Dyna® and 2007-16 big twin models.
Note: Special valve springs will be needed.
Fuel injection tuning required.
Pinion shaft run-out must be checked before installing S&S® gear drive cams.
A hydraulic press and other professional tools are required to install S&S
gear drive cams. Additionally, material must be removed from the inner
surface of the stock gearcover. The stock crankcase may require clearancing
for S&S .625", .640", and .675" lift cams. S&S recommends that gear drive
cams be installed by a professional mechanic.
Due to the inheraent 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 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.
Not legal for sale or use on CA or EPA pollution controlled motorcycles.