Inspired by our Pro Stock Drag Race engines, these updated big bore kit utilizes a Ductile Cast Iron liner wrapped in cast aluminum for optimum thermal conductivity and performance. Bolt-in kits do not require machining, rebalancing or engine removal, and include just about everything you’ll need to complete the installation. The biggest cylinder bore that can be installed in a stock crankcase without machining!
Features & Benefits
- Low friction Ductile Cast Iron liner
- 10.5:1 Compression -Bolts in. No machining, balancing, or splitting the crankcases
- 96 and 103" engines are boosted to 110"
- Complete kits include cylinders, pistons, gaskets, and instructions
- Wrinkle black cylinders – matches stock finish
- Although not mandatory, we recommend adding an oil cooler to bikes ridden in warmer climates
| Stroke | Bore | Cylinder Length | Piston Type | Dome Volume | 83cc CNC Heads | 85cc Stock Heads | 89cc S&S Heads |
| 4.375 | 4.00" | 4.937" | Forged | .75 pop up | 10.7:1 | 10.5:1 | 10.2:1 |
*Not compatible with S&S 79cc Super Stock® heads and 2014-'16 Twin-Cooled™ touring models. S&S does not recommend compression ratios higher than 10:1 for Tri Glide® or other three wheel models (including conversions) due to extra loads caused by the lugging nature of these bikes. Detonation and subsequent engine damage may result.
DISCLAIMER:
NOT LEGAL FOR SALE OR USE IN CALIFORNIA ON ANY POLLUTION CONTROLLED MOTOR VEHICLE. Not legal for sale or use on any EPA pollution
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FLS Slim Is Now a Monster
Fairly easy installation. Technical Support and Customer Service are excellent. I expect a DRAMATIC power increase as I mixed these with HD SE 254E Cams, Roller Lifters and my V&H FP3 Tuner.
