The Namura NA-50019K Top End Kit is a complete standard-bore replacement solution for select Polaris 570 powersports applications. Designed for reliable engine rebuilding, this kit includes a piston, piston rings, wrist pin, wrist-pin clips, top-end bearing, and gasket kit. It is engineered for compatible 570 models using a 98.94 mm standard-bore piston and an 11:1 compression ratio.
Namura applies a MOS2, or Teflon and molybdenum, coating to the piston skirts using a rolled-on process that creates a bond significantly stronger than many spray-on coatings. This coating helps improve heat transfer, reduce friction, and minimize the risk of cold seizures. Machined smooth piston heads reflect combustion heat and help reduce carbon buildup, supporting piston protection and consistent engine performance.
The piston features an anodized dome for improved heat resistance and durability, with greater strength than non-anodized designs. Its hypereutectic casting process increases silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. These features make the Namura top-end assembly well suited for service, repair, or rebuild work where dependable fit and durability are required.
Fitment includes the 2014–2016 Polaris Ranger 570 EPS, 2015–2016 Polaris Ranger 570 Fullsize, 2016–2017 Polaris ACE 570, and 2015–2017 Polaris Sportsman 570 SP. Verify the vehicle model, year, bore specification, and compression requirements before installation. Manufacturer part number: NA-50019K. Vendor part number: 186-5019.
Features:
- Complete top-end kit includes piston, rings, wrist pin, clips, top-end bearing, and gasket kit
- MOS2 Teflon and molybdenum coated skirts help reduce friction, improve heat transfer, and minimize cold-seizure risk
- Machined smooth piston head helps reflect combustion heat and reduce carbon buildup
- Anodized dome improves heat resistance and piston durability
- Hypereutectic casting process provides controlled expansion, increased wear resistance, and improved high-temperature performance
- 98.94 mm standard-bore piston with an 11:1 compression ratio
- Brand: Namura
- Manufacturer part number: NA-50019K
- Vendor part number: 186-5019
- Fits select 2014–2017 Polaris Ranger 570, ACE 570, and Sportsman 570 SP models
Fitment:
2012 Polaris RZR 570
2013 Polaris RZR 570
2014 Polaris Ranger 570
2014 Polaris Ranger 570 EPS
2014 Polaris Ranger 570 [Fullsize]
2014 Polaris Ranger Crew 570
2014 Polaris Ranger Crew 570 EPS [Fullsize]
2014 Polaris Ranger Crew 570 [Fullsize]
2014 Polaris RZR 570
2014 Polaris Sportsman 570
2014 Polaris Sportsman 570 EPS
2014 Polaris Sportsman Touring 570
2015 Polaris Ranger 570
2015 Polaris Ranger 570 EPS
2015 Polaris Ranger 570 [Fullsize]
2015 Polaris Ranger Crew 570
2015 Polaris Ranger Crew 570 EPS [Fullsize]
2015 Polaris Ranger Crew 570 [Fullsize]
2015 Polaris RZR 570
2015 Polaris Sportsman 570
2015 Polaris Sportsman 570 EPS
2015 Polaris Sportsman 570 SP
2015 Polaris Sportsman Touring 570
2015 Polaris Sportsman Touring 570 EPS
2015 Polaris Sportsman Touring 570 SP
2015 Polaris Sportsman X2 570 EPS
2016 Polaris ACE 570
2016 Polaris Ranger 570
2016 Polaris Ranger 570 EPS
2016 Polaris Ranger 570 [Fullsize]
2016 Polaris Ranger Crew 570-4
2016 Polaris Ranger Crew 570-4 EPS
2016 Polaris Ranger XP 570
2016 Polaris Ranger XP 570 EPS
2016 Polaris RZR 570
2016 Polaris Sportsman 570
2016 Polaris Sportsman 570 EPS
2016 Polaris Sportsman 570 SP
2016 Polaris Sportsman Touring 570
2016 Polaris Sportsman Touring 570 EPS
2016 Polaris Sportsman Touring 570 SP
2016 Polaris Sportsman X2 570 EPS
2017 Polaris ACE 570
2017 Polaris Ranger 570
2017 Polaris Ranger 570 EPS
2017 Polaris Ranger 570 [Fullsize]
2017 Polaris Ranger Crew 570-4
2017 Polaris Ranger Crew 570-4 EPS
2017 Polaris RZR 570
2017 Polaris Sportsman 570
2017 Polaris Sportsman 570 EPS
2017 Polaris Sportsman 570 SP
2017 Polaris Sportsman 6X6 570 EPS
2017 Polaris Sportsman Touring 570
2017 Polaris Sportsman Touring 570 EPS
2017 Polaris Sportsman Touring 570 SP
2017 Polaris Sportsman X2 570 EPS
2018 Polaris ACE 570 EPS
2018 Polaris Ranger 570
2018 Polaris Ranger 570 EPS
2018 Polaris Ranger 570 [Fullsize]
2018 Polaris Ranger Crew 570-4
2018 Polaris Ranger Crew 570-4 EPS
2018 Polaris RZR 570
2018 Polaris Sportsman 570
2018 Polaris Sportsman 570 EPS
2018 Polaris Sportsman 570 SP
2018 Polaris Sportsman 6X6 570 EPS
2018 Polaris Sportsman Touring 570
2018 Polaris Sportsman Touring 570 EPS
2018 Polaris Sportsman Touring 570 SP
2018 Polaris Sportsman X2 570 EPS