Redefining Piston Performance for Harleys
CYPRESS, Calif. (September 25, 2024) – JE Pistons, an industry leader in custom and shelf-stock high-performance forged pistons and Company under the Race Winning Brands (RWB) umbrella, is excited to announce the launch of its Ultra Series pistons for Harley-Davidson Milwaukee-Eight (M8) engines. The proprietary Ultra Series piston platform has proved itself with industry-leading strength for automotive and powersports engines over recent years and is now redefining what pistons for Harley’s M8 engine platform can be capable of.
The key to what sets Ultra Series pistons apart from the competition is JE’s proprietary Aligned Grain Flow technology. Being one of the only fully integrated piston manufacturers in the USA, JE’s in-house forging operation has allowed for the development of an improved forging process that maximizes the alignment of the aluminum’s grain structure, translating to next-level tensile strength. This enables the pistons to stand up to extreme power M8 builds of 400 HP or more, or simply offer extreme durability for more mild builds.
Ultra Series pistons combine this foundational strength with performance and durability-enhancing features, including JE’s Thermal Barrier crown coating, Tuff Skirt coating, anti-detonation grooves, lateral gas ports, an accumulator groove, and more. The ceramic-based Thermal Barrier crown coating protects the piston by reducing heat transfer, especially in high-heat environments like built M8 engines. Piston ring provisions including lateral gas ports and an accumulator groove both aid in maintaining consistent ring seal at the top compression ring, which is crucial to consistent power, especially when power adders like turbos get thrown into the mix
In addition to the Aligned Grain Flow material itself, the forging design of Ultra Series pistons for M8 engines have been optimized with internal and external bracing, features not commonly seen in V-twin piston design. This helps mitigate piston flex under heavy engine loads, adding to the pistons’ strength qualities without adding unnecessary weight.
Finishing details of the Ultra Series pistons for M8 engines include 3D undercrown milling for additional weight savings, offset pins for reduced piston rock, and skirt notches for optimal clearance at the bottom dead center.
These Ultra Series pistons are available in standard, 4.310” and 4.320” bore sizes, each with the option of a 10.25:1 or 11.25:1 compression ratio. Ultra Series M8 pistons are supplied in kits including two pistons, rings, wrist pins, and locks.
Check out the Detailed Video Below
To see more on these pistons and JE’s complete lineup for Harleys – CLICK HERE.
