Kb Pistons Super Duty Piston - 4.250" Bore M8 107 TO 124" +.005 11.4:1 — Harley-Davidson (2017-2021)
KB Pistons Super Duty piston set for M8 Harley-Davidson and Indian Motorcycle big-twin engines, sized for 4.250" bore and 107–124" displacement builds. Sold as a matched pair with premium rings, wrist pins, and locks included.
Features
- Anodized top ring groove and crown
- Line2Line Abradable skirt coating (.003" total) for zero initial clearance and tight, quiet running
- Round wire wrist pin locks
- Premium Hastels 1.2mm Steel Nitride top ring with Ductile Napier second ring
- Forced wrist pin oiling
- Flat-top dome with 1.2cc bowl and 1.083" compression height
- Valve pockets sized for 1mm oversize valves
- Sold as a pair with all rings and pins included
Specifications
- Brand: KB Pistons
- Manufacturer Part #: KB576LCA.005
- UPC: 800745266958
- Application: M8 engines 107–124 cubic inches
- Bore Size: 4.250 inches
- Compression Height: 1.083 inches
- Top Design: Flat top, 1.2cc bowl
- Quantity: Pair (2 pistons)
- Weight: 2.5 lbs
- Country of Origin: Mexico
Fitment
Fits Harley-Davidson and Indian Motorcycle V-twin big-twin engines with M8 architecture, 4.250" bore displacement. Suitable for 107–124 cubic-inch builds.
Frequently Asked Questions
What's included in the box?
Pair of pistons, premium top and second rings, wrist pins, and round wire locks — everything needed to complete a piston installation.
What does Line2Line Abradable skirt coating do?
The .003" coating provides zero initial clearance and self-hones during break-in to achieve a tight, quiet fit that reduces piston noise.
Will these pistons fit my 110" or 117" build?
Yes — KB designed these for 107–124 cubic-inch M8 stroker applications with a 4.250" bore.
Can I use these pistons with 1mm oversize valves?
Yes — the valve pockets are specifically sized to accommodate 1mm oversize valves without interference.
Are these pistons sold as singles or pairs?
Sold as a matched pair only. You receive two pistons, ready for a complete V-twin engine rebuild.
| BRAND | Kb Pistons |
| TYPE | Piston kits & Components |
| SKU | 824-01831 |
| WEIGHT | 2.5 lb |
