Super Stock® heads intended for larger displacement engines, S&S 89cc heads have a whopping 264cfm flow rate (compared to 182cfm for stock H-D® heads), larger valves and .640 inch lift valve springs. S&S recommends Easy Start cams or manual or electric compressions release system in order to maintain reliable engine starting on high compression applications.
- 1999–2006 Big Twin Models
- Stock and 3-7/8 inch bore
- Heads can be decked up to .060 inch to increase compression
- 2.000 inch intake and 1.605 inch exhaust valves
- S&S .640 inch lift valve springs
- Stock Harley-Davidson® rocker boxes can be retained if S&S manual compression release or S&S Easy Start cams are used.
- Must use S&S valve cover gasket part #90-4124 with stock rocker covers
Silver. . . . .106-4270
Black . . . . .90-1106
Compression Ratios for S&S®
Super Stock® Cylinder Heads for
1999–Up Big Twins |
| Engine Displacement & Configuration |
Chamber Volume |
| |
79cc |
89cc |
| 88" |
9.1 |
8.3 |
| 95" |
9.6/10.3* |
8.7/9.3* |
| Stock 2007–up 96" |
9.8 |
8.9 |
| 97" Big Bore |
10.3 |
9.4 |
| 103" |
10.2/11.1* |
9.3/10.1* |
| 106" Stroker |
10.7 |
9.8 |
| 106" Top End Kit |
10.6 |
9.7 |
| 110" |
10.8 |
9.8 |
*S&S pop-up piston
|
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 maximum 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 valve cover gasket kit part #90-4120 with stock rocker covers.
