JE Pistons / SRP · 378136
Part #: 378136
UPC: 193564440792
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Description: Ultra Series - Subaru EJ257 Piston Kit - 100.00/28.70/-21.50; 100.00 mm Bore - 28.70 mm CD - (-21.50 cc) - 4 Cyl. Piston Kit
Description:
Description
Accumulator Groove, Smooth Crown Finish, Pin Fit, Thermal Crown, Lateral Gas Ports, and Skirt Coat. Ultra Series pistons are made 100% in the USA.
Features & benefits
- JE’s proprietary Aligned Grain Flow forging technology providing next-level tensile strength ideal for the extreme cylinder pressures of power adder engine builds.
- Lateral Gas Ports: This process mills slots into the top of the top ring groove and provides a pathway for combustion pressure to get behind the top ring. Resulting in increased ring seal and is most common in circle track applications.
- Skirt Coat: Skirt Coat reduces friction and wear on piston skirts and cylinder walls while simultaneously reducing operating noise
- Designed specifically for Subaru STI EJ257 Engines. To provide optimized performance durability
- Includes high-quality wrist pins, locks, and JE Pro Seal premium piston rings
- Made 100% in the USA
- Accumulator Groove: A specialty groove between the top and second ring provides added volume for blow-by gases. This helps reduce pressure between the rings, improving top ring seal and minimizing ring flutter at high cylinder pressures.
- Smooth Crown Finish: Deburs all areas around the valve pocket and dome area, to reduces stress risers and prevent hot spots.
- Pin Fit: The pin bore is precision honed to attain an exact pin clearance. Clearances typically range from .0003 to .0010 between the wrist pin and pin bore.
- Thermal Crown: Applied to the piston crown, this thermal barrier coating reflects heat back into the combustion chamber to improve exhaust gas velocity and scavenging while reducing heat transfer to help extend piston life.
Information
These pistons utilize our dedicated Forged Side Relief (FSR) forging that was specifically designed to increase strength.
Specifications
- GTIN
- 00193564440792
- Weight
- 5.1 lb
- Height
- 5 in
- Length
- 5 in
- Width
- 9 in
- EO
- Offroad
- Life cycle
- Available to Order
- Warehouse brand code
- JEP
- AAIA brand code
- BHXG
Attributes
- 2nd Groove Width
- 0.04800
- 3D Undercrown Milling
- No
- Accumulator Groove
- Yes
- Anodize Top Ring Groove
- No
- Bore Diameter
- 100.00
- Bore Diameter - Web
- 100.00
- California Proposition 65
- WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
- Category Hierarchy
- Auto>JE Ultra Series>Piston Kits
- Combo 2
- No
- Compression Height
- 28.70
- Compression Ratio
- 8.50:1
- Connecting Rod Length
- 130.50
- Contact Reduction
- No
- Cylinder Head
- EJ257 STI
- DVGP
- No
- Double Pin Oilers
- No
- EBAY Category ID
- 33623
- EN Plating
- No
- Econo Undercrown Milling
- No
- Engine
- EJ257
- Engine - Web
- EJ257
- Engine Detail
- 2004-2017 Impreza STI, 2005-2006 Outback XT/Legacy GT
- Engine Displacement
- 2457
- Engine Family
- EJ Series
- Engine Stroke
- 83.00
- Engine Type
- ICE
- Exhaust Angle
- 13
- Exhaust Depth
- .195
- Exhaust Diameter
- 1.290
- Forging Type
- FSR
- Gas Distribution
- No
- Industry
- Automotive
- Intake Angle
- 13
- Intake Depth
- .190
- Intake Diameter
- 1.540
- Lateral Gas Ports
- Yes
- Make
- Subaru
- Make - Web
- Subaru
- Mill Undercrown
- No
- OEM Bore Diameter
- 99.50
- Oil Groove Width
- 0.09950
- Out of Stock Message
- Call for Availability
- Oversized
- Yes
- Oversized Amount
- 0.50
- Pin Fit
- Yes
- Piston Average Weight
- 404
- Piston Head Type
- Inv Dome/Dish
- Piston Material
- 2618
- Piston Quantity
- 4
- Piston Series
- JE Ultra Series
- Piston To Wall Clearance
- -0.004
- Piston Volume
- -21.50
- Product Market
- Sport Compact
- Product Type
- Engine Piston Kit
- Ring Quantity
- 4
- Ring Set Included
- Yes
- Ring Set Part Number
- JG4904-3937
- Ring Set Thickness
- 1.20 MM x 1.20 MM x 2.50 MM
- Skirt Coat
- Yes
- Smooth Crown Finish
- Yes
- Stroke
- 3.268
- Thermal Crown
- Yes
- Title
- JE Pistons Ultra Series Subaru EJ257 Stroker Piston Kit
- Title - Web
- JE Pistons Ultra Series Subaru EJ257 Stroker Piston Kit
- Top Groove Width
- 0.04750
- Tuff Skirt
- No
- Ultra Dome
- No
- Ultra Groove
- No
- Ultra Groove Plus Gas Port
- No
- Vertical Gas Ports
- No
- Wrist Pin Included
- Yes
- Wrist Pin Length
- 2.250
- Wrist Pin Outer Diameter
- 0.905
- Wrist Pin Part Number
- 905-2250-21-93S
- Wrist Pin Quantity
- 4
- Wrist Pin Retainer Included
- Yes
- Wrist Pin Retainer Part Number
- 905-042-CT
- Wrist Pin Retainer Quantity
- 8
Fitment status
This product is universal and will fit your application.
