The NAMURA NA-50080-BK1 Top End Kit is designed for select Polaris Ranger 800 models and provides the essential components needed for a dependable top-end rebuild. This kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit. The 79.96 mm piston size with a 11:1 compression ratio is engineered for compatible Polaris Ranger applications and supports reliable engine performance when installed according to manufacturer specifications.
The piston uses a hypereutectic casting process that increases silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. MOS2, or Teflon/Molybdenum, coated skirts are applied using a rolled-on process that creates a strong bond while helping reduce friction, improve heat transfer, and minimize the risk of cold seizures. Machined smooth heads help reflect combustion heat and reduce carbon buildup, while the anodized dome improves heat resistance and durability.
This NAMURA top-end kit fits the 2013 and 2014 Polaris Ranger 800 4x4 Midsize, 2011 through 2014 Polaris Ranger Crew 800 4x4, and 2011 through 2014 Polaris Ranger 800 6X6. Verify the exact model, year, engine configuration, piston size, and required compression ratio before installation. Manufacturer part number: NA-50080-BK1. Vendor part number: 186-5080B1.
Features:
- Complete Top End Kit: Includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit.
- MOS2-Coated Skirts: Rolled-on Teflon/Molybdenum coating helps reduce friction, improve heat transfer, and minimize cold-seizure risk.
- Machined Smooth Head: Helps reflect combustion heat and reduce carbon buildup on the piston crown.
- Anodized Dome: Improves heat resistance and durability for demanding engine operating conditions.
- Hypereutectic Construction: Higher silicon content helps control expansion, improve wear resistance, and withstand increased cylinder temperatures.
- Fitment: Fits 2013-2014 Polaris Ranger 800 4x4 Midsize, 2011-2014 Polaris Ranger Crew 800 4x4, and 2011-2014 Polaris Ranger 800 6X6.
- Manufacturer Part Number: NAMURA NA-50080-BK1.
- Vendor Part Number: 186-5080B1.
Fitment:
2011 Polaris Ranger 800 4x4
2011 Polaris Ranger 800 6X6
2011 Polaris Ranger Crew 800 4x4
2012 Polaris Ranger 800 6X6
2012 Polaris Ranger Crew 800 4x4
2013 Polaris Ranger 800 4x4
2013 Polaris Ranger 800 4x4 [Midsize]
2013 Polaris Ranger 800 6X6
2013 Polaris Ranger Crew 800 4x4
2014 Polaris Ranger 800 4x4
2014 Polaris Ranger 800 4x4 [Midsize]
2014 Polaris Ranger 800 6X6
2014 Polaris Ranger Crew 800 4x4
2016 Polaris Ranger 800 6X6