JE Pistons
JE Pistons Subaru EJ20 Head/EJ25 Block Ultra Series 3.927 in. Bore Kit Set of 4 Pistons
SKU: J001 367904
Description
Part #: 367904
Ultra Series forged pistons from JE are the industry s strongest, most fully featured pistons available off the shelf. Offered for a wide range of import and sport compact applications from 2JZ to 4G63 and Audi to BMW, Ultra Series pistons feature JE s proprietary Aligned Grain Flow forging technology providing next-level tensile strength ideal for the extreme cylinder pressures of power adder engine builds. Equipped with custom level features including thermal barrier crown coating, skirt coating, gas ports, and more, Ultra Series are the ideal pistons for your high-boost build. As with all JE Pistons products, Ultra Series pistons are made 100% in the USA.
Features:
- Designed for Power: Every feature on Ultra Series Pistons are optimized to perform high-horsepower racing engines
- Aligned Grain Flow Technology: Exclusively available on JE Ultra Series, this proprietary, in-house forging process maximizes tensile strength to withstand the stresses of high-performance engine environments
- Skirt Coating: Reduces friction and wear on piston skirts and cylinder walls while simultaneously reducing operating noise, especially on cold start
- Thermal Barrier Crown Coating: This ceramic-based coating reflects heat into the combustion chamber, therefore reducing piston crown temperatures and improving exhaust gas scavenging
- High-Strength Wrist Pins: Premium thick-wall wrist pins are manufactured by Trend Performance in the USA and are designed for the demands of high-performance/power-adder builds
- Lateral Gas Ports: Help maintain power-producing ring seal at the top compression ring, even in high RPM and high boost situations
- Optimized Pin Oiling: Enhanced pin oiling features keep pin, pin bores, and small-end lubricated for reduced heat, friction, and wear
- Made 100% in the USA
JE Ultra, Subaru, EJ Series, 3.927 in. Bore, 8.50:1, Inverted Dome/Dish, 4 Cyl. Piston Kit
This product may expose you to chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.
Fitment
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Specifications
| Brand | JE Pistons |
| Part Number | J001 367904 |
Videos
Project Import: JE Pistons 291060 for EJ25 block w/ EJ20 heads
Introducing the Strongest Pistons in Powersports | JE Ultra Series
How to Measure Piston to Wall Clearance on a JE Perfect Skirt Piston
How to Build a Subaru EJ Engine that won't BLOW UP!
What is a Subaru/WRX Hybrid Swap?
SUBARU Engine Rebuild - Long Block Assembly - Part 1
Subaru EJ25 Short Block Assembly Part 2
Subaru Engine Rebuild, How to Set Piston Ring Gap
Buy with Confidence
Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
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