S&S Cycle

2007–2017 big twins

Milwaukee-Eight ®

79cc heads When 79cc stock compatible heads are used with stock HD® pistons, TDC lifts of up to .186" for intake and .179" for exhaust and can be used without additional valve pocket clearancing. This allows the use of S&S® 510, 570, and 585 camshafts. If cams with higher TDC lifts are used, or if the heads are decked, piston valve pocket machining will be required. 79cc heads may be decked as much as .060" to increase compression. If heads are decked, piston valve pockets must be re-machined. Moderate valve spring force in S&S Super Stock® cylinder heads allows the use of camshafts designed for the stock style chain cam drive system. However, for maxi- mum reliability and performance we recommend the S&S gear drive cams. Must use S&S rocker base gasket kit part #90-4120 with stock rocker covers. 79cc Heads should not be used with any piston having a pop up dome. 89cc heads If 89cc heads are used with stock pistons, valve reliefs must be machined in the pistons due to larger valve size. 89cc heads may be decked as much as .060" to increase compression. If heads are decked, valve-to-piston clearance must be checked. If stock pistons are used, valve pockets must be re-machined. Moderate valve spring force in S&S® Super Stock® cylinder heads allows the use of camshafts designed for the stock style chain cam drive system. However, for maxi- mum reliability and performance we recommend the S&S gear drive cams. A larger intake manifold is recommended to supplement the heads in order to let them flow to their full potential. Must use S&S rocker base gasket kit part #90-4120 with stock rocker covers.

NOTES

96 ™ /103 ™ /110 ™

2007–2017 Twin Cam

1999–2006 Twin Cam 88 ®

Sportster ® & Buell ® Indian ® Models Street Rod ™

1986–2019

91cc heads By changing the profile and shape of the cooling fins on our heads for 41/8" bore engines, a large reduction in the transmission of mechanical noise was found. This not

only benefits our TÜV certified engines and our EPA approved engines, but our performance engines as well! Since April 1, 2007, these redesigned heads have been installed on all S&S 41/8" bore engines and Hot Set Up Kits. Replacement heads of the old style are available by special order. Must use S&S valve cover gasket kit part #90-4120 with stock rocker covers.

2014–2019 Street ® &

MANIFOLD RECOMMENDATIONS S&S single bore throttle body and manifold are recommended for engines with Magneti Marelli® fuel injection. Due to the change in manifold flange mounting bolt pattern, stock flanges and S&S seal part #16-0235 must be used. The Screamin’Eagle® 58mm throttle body/manifold may also be used on 2006-'09 engines. We recommend the stock 50 mm throttle body or S&S Throttle Hog 58mm throttle body/manifold for 2008-up touring models with Electronic Throttle Control (ETC).

IMPORTANT MANIFOLD INFORMATION In 2006, Harley-Davidson® changed the bolt pattern of the flanges that connect the manifold to the cylinder heads for all big twin engines. The pattern was changed from an offset bolt pattern to a symmetrical bolt pattern, so flanges can fit either the front or rear cylinder head. In addition, the intake port was moved slightly toward the drive side of the engine, making the port-to-port distance of the intake manifold slightly shorter. S&S® heads for 2006–up big twins are machined with the symmetrical bolt pattern and relocated port to allow for the fitment of stock manifolds. In 2008, Harley-Davidson touring models were equipped with electronic throttle control (ETC). The throttle body and manifold used on these engines is a one-piece unit that contains a servomechanism to control the position of the throttle plate. S&S recommends the S&S Throttle Hog throttle body for this application, see page 107. This limits the cylinder length of engines using an ETC manifold/throttle body to stock length because the ETC manifold/throttle body units are only available in stock length. However, S&S does supply specially machined cylinder heads for our 124" Hot Set Up Kit® for 2008 and later baggers, which allows the use of a stock length manifold on these longer-than-stock engines.

REPLACEMENT PARTS: SEE PAGE 128

Tools & Shop Supplies

Warranty & Company Policy

Index

Appendix &

103