LS7 Asymmetrical FSR Flat Top Forged Piston J311989

4.185" bore, 4.000" stroke, 6.125" rod length, -5cc dome volume

J311989

11989

GM LS Flat Top Our brand new Asymmetrical FSR (Forged Side Relief) forging design allows for the use of the most popular stroke and rod combinations while eliminating reluctor wheel clearance problems. Asymmetrical forging design maintains a larger skirt on the heavily stressed major thrust side, while reducing friction with a smaller skirt on the minor thrust side. The result is a high strength, lightweight piston that significantly reduces friction in your engine. Lightweight and extremely durable, these pistons are machined for 1.2mm, 1.5mm, 3.0mm rings. Includes: .927 x 2.250 straight wall carbon steel wrist pin Wire locks Specifications: Part #: J311989 Bore: 4.185" Oversize: .060" LS7 Stroke: 4.000 Rod Length: 6.125" Compression Height: 1.115" Compression Ratio with 64cc chamber volume: 12.5 Compression Ratio with 68cc chamber volume: 11.9 Compression Ratio with 70cc chamber volume: 11.7 Dome Volume: -5cc Gram Weight: Footnote: For ged Side Relief Reconmended Ring Set: J91008-4185-5 With over 60 years of experience, JE Pistons is the leader in high performance forged pistons. We've built a reputation that the competition can only follow. JE has a history of manufacturing the highest quality pistons and components that professional engine builders, race teams, and high performance enthusiasts trust and rely on. The top engine builders in NASCAR, ALMS, NHRA, AMA Supercross and others choose JE Pistons over any other brand. For over 60 years, JE's position at the forefront of performance piston manufacturing has been a result of continuous research and development of unique materials, piston designs and technologies. Utilising State-Of-The-Art CNC machines for manufacturing along with purpose-designed forgings, JE is able to maintain exacting specifications on each and every piston and hold tolerances to millionths of an inch. Also available from JE is industry-leading processes like Ultra Crown, a Digital Three Dimensional piston crown machining process and Finite Element Analysis (FEA). FEA is a computer processwhereby stress and fatigue are tested on a computer model before it goes into production. JE is the only performance piston manufacturer to earn the QS-9000 quality standard which confirms that JE provides customers the highest standards in quality control. In addition, we also have State-Of-The-Art inspection equipment and testing equipment which enables us to constantly bring you, the customer, the very latest in piston design configurations.