These cases are cast from aircraft grade A206 aluminum, for exceptional strength, and are precision CNC machined to maintain the highest dimensional accuracy. S&S® special application (SA) big bore crankcases for 1999–up big twins are intended for use in stock Harley-Davidson® chassis and will bolt directly to the stock Harley-Davidson® transmission in place of the stock Twin Cam 88® engine. These crankcases are recommended for any racing or high performance street application. Available in natural aluminum finish only.
Features and Benefits
- Can be ordered for 4.375" to 4.800" bore engines
- Cam chest on the right side has been offset .375"—requires a special .375" longer pinion shaft
- Deck height can be machined to the stock height of 6.000" or as high as 7.125" from the crank center line—allows for more material and greater strength between the cylinder spigot bores
- Optional stock cam geometry—allows the engine builder to select from a wide variety of readily available cams
- Optional special rotated S&S cam geometry—improves the pushrod angles for more direct application of force to the rocker arms, hence more accurate valve actuation. (Cases machined for this option require specially ground cams. These cams are not currently available from S&S and must be special ordered from the cam manufacturer.)
4 3/8" Bore – stock geometry . . . . . . . . . . . . . . . .106-0505
Special Order* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106-0719
Special order options:
4.600" Bore – standard stock cam geometry only
*Not available for Twin Cam 88B™ engines or 2006 Dyna® or any 2007 models.
*Not available for Twin Cam 88B™ engines or 2006 Dyna® or any 2007-up models.Special order sheet is required. Download the Special Order Sheet from our website www.sscycle.com/soforms. Not legal for sale or use on CA or EPA pollution controlled motorcycles.