Page 387 of High Performance Parts for American V-Twins 2008 by S&S Cycle

1958-2008 50th ann iversary s&s® gear drive camshaft kits for 1999-up big twin engines meeting the needs of high performance engines the patented s&s gear drive cams are a must in order to achieve the full potential from high performance harley-davidson® twin cam 88® engines since the chain drive system used in stock twin cam 88 engines is not adequate to accurately control valve action at high rpm when using high lift cams and high performance valve springs a different system was needed the s&s gear drive system was developed to improve performance and to eliminate potential engine damage caused by failure of the chain and tensioner system improved timing accuracy and less drag s&s gear drive camshaft kits improve valve timing accuracy by eliminating timing chain lash as well as variations caused by the loose fitting stock cam drive sprockets all stock chain drive components are replaced with s&s gear drive cams and outer drive gears this simple effective solution provides two to three more horsepower simply by eliminating chain drag and allows more aggressive cam profiles and increased valve spring force to be used higher possible lifts the s&s camshaft gear drive kit reverses the rear cam s direction of rotation as a result the lobes on the front and rear cams never directly face each other as the stock cam lobes do this provides additional operating clearance between the lobes the increased clearance between the cam lobes allows lobes to be taller therefore higher lift is possible s&s® gear drive cam specifications cam name 510g 546g 570g 585g 625g 640g 675g complete kit 33-5177 33-5230 33-5178 33-5179 33-5180 33-5181 33-5231 msrp $719.95 $719.95 $719.95 $719.95 $744.95 $744.95 $769.95 valve timing open/close intake 20°/38° 5°/55° 20°/40° 20°/45° 20°/55° 25°/60° 25°/64° exhaust 52°/20° 52°/5° 55°/20° 60°/20° 60°/20° 65°/25° 70°/25° valve duration intake 238° 240° 240° 245° 255° 265° 269° exhaust 252° 237° 255° 260° 260° 270° 275° valve lift .510 .546 .570 .585 .625 .640 .675 centerline intake 99.0° 115.0° 100.0° 102.5° 107.5° 107.5° 109.5° exhaust 106.0° 113.5° 107.5° 110.0° 110.0° 110.0° 112.5° lift tdc intake .187 .126 .187 .186 .189 .228 .235 exhaust .178 .106 .179 .179 .184 .214 .205 order toll free 866-244-2673 9-2

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