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JE Pistons Kit LS ASYM DOME B:4.155

Partnumber: JE-312103
1,125.43 € 1,125.43 € (Tax included)

  • Brand
  • Block Height
  • Bore - Actual
  • Bore - Oversize
  • Build Type
  • Compression Height
  • Compression Ratio - Actual
  • Cylinder Head
  • Displacement
  • Dome Volume
  • Piston Head Type
  • Piston Pin Diameter
  • Ring Set Recommended
  • Rod Length
  • Stroke
  • Weight - Nominal
  • Packaging
Product specifications
Brand: JE
Block Height: 9.240
Bore - Actual: 4.155
Bore - Oversize: .030 LS7
Build Type: Build on Demand
Compression Height: 1.304
Compression Ratio - Actual: 12.2:1 @ 70cc
Cylinder Head: GM LS1 15 DEG
Displacement: 393
Dome Volume: 7.5
Piston Head Type: Dome
Piston Pin Diameter: 0.927
Ring Set Recommended: JG31F8-4155-3
Rod Length: 6.125
Stroke: 3.622
Weight - Nominal: 479

JE Pistons



Over a Century of Piston Engineering

JE Pistons traces its origins to 1912, when William Jahns Sr. established his Los Angeles foundry under the motto "Nothing but Pistons." The lineage continued through his son William "Uncle Bill" Jahns Jr., who founded Jahns' Engineering Pistons in 1947, a company that would eventually become JE Pistons. From those early roots, the brand has evolved continuously: mastering casting technology in the 1960s, pioneering forging in the 1970s, and introducing CNC machining alongside a proprietary piston design programme in the 1980s.


In-House Manufacturing, Total Control

Every JE piston is designed, forged, and machined entirely in-house, a deliberate choice that ensures complete control over every stage of the manufacturing process. This vertical integration, built over more than seven decades of high-level racing involvement, allows JE to maintain the precision and consistency that performance engine builders demand. The result is a product range that includes both off-the-shelf racing pistons and fully custom solutions, available with premium features such as full billet construction, EN plating, and purpose-designed coatings.


A Racing Pedigree That Speaks for Itself

JE Pistons has spent decades at the sharp end of motorsport, accumulating the kind of real-world experience that no laboratory can replicate. That racing knowledge feeds directly into every product they manufacture, whether it is destined for a top-level competition engine or a serious performance street build. For engine builders who understand that the piston is one of the most critical components in any high-performance application, JE Pistons remains one of the most trusted names in the industry.