JE PISTONS - 394138 - Piston Kit - 4.250” - 10.25:1 CR - 114”/117” M8
When your engine rebuild demands the best, the JE PISTONS 394138 delivers the precision machining and premium materials that professional builders rely on. Propriety aligned grain flow forging technology for maximum tensile strength suited for high performance enviroment. Cermic crown coating protects the piston by reducing heat transfer. Internal and external bracing maintains optimized strength-to-weight ratio for longevity. 3D undercrown milling in non-critical areas reduces overall weight. Note: Piston Average Weight: 445 grams Designed for Street applications. Sold as a kit.
Features
- Propriety aligned grain flow forging technology for maximum tensile strength suited for high performance enviroment
- Cermic crown coating protects the piston by reducing heat transfer
- Internal and external bracing maintains optimized strength-to-weight ratio for longevity
- 3D undercrown milling in non-critical areas reduces overall weight
- Lateral gas ports and accumulator groove maintain power-producing ring seal even at high RPM and high boost
- Tuff Skirt is a propriety, moly based dry film skirt coating that is applied in-house and reduces operating friction for better wear resistance
- Offset pin reduces piston rock and minimize engine operating noise
- Skirt notches for optimal clearance at the bottom dead center
- Kit includes two pistons, premium ring pack, wrist pins and wire locks
Specs
- Units: Kit
- Piston Head Shape: Dished
- Skirt Coating: Tuff Skirt
- Compression Ratio: 10.25:1
- Bore - Oversize: Standard
- Piston Material: Forged 2618 Aluminum
- Model: Ultra Series
- Product Name: Piston Kit
- Type: Forged Side Relief Design
- Bore Size: 4.250”
- Stroke Length: 4.500”
- Bore Oversize: Standard
- Riding Style: Street
Frequently Asked Questions - JE PISTONS - 394138 - Piston Kit - 4.250” - 10.25:1 CR - 114”/117” M8
How do I know if this part fits my vehicle?
Check the fitment information listed on this page against your exact year, make, model, and (where applicable) trim, engine size, or configuration. If your exact vehicle isn't listed, or you're not sure, use the product chat on this page or contact our support team before ordering - we're glad to help confirm fitment.
What does it mean if a product is listed as universal fit?
Universal fit means the product is designed to work across a range of vehicles, not that it's guaranteed to fit every one. Compare the listed measurements, mounting requirements, and connector or hardware specs against your specific vehicle before ordering, since some installations may need additional hardware or minor fabrication.
Where can I find installation instructions for this product?
General installation notes are provided above where available. For detailed step-by-step instructions, refer to the manufacturer's documentation included with the product, or use the product chat on this page for questions about difficulty, required tools, or whether professional installation is recommended.
What if I have more questions about this product?
Use the product chat on this page for fitment, specs, installation, and compatibility questions, or contact our support team directly for help before you order.
