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Ultra Series forged pistons from JE are the industry’s strongest, most fully featured pistons available off the shelf. Offered for Subaru STI EJ257 Engines. 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 the following custom level features
JE pistons are all designed, forged, and machined in-house, allowing control over every step of the piston-making process. JE Pistons 7+ decades of experience in high-level racing has led to offering premium racing features, including full billet construction, EN plating, and purpose-designed coatings, to name a few.
| 2nd Groove Width | 0.048 in |
|---|---|
| 3D Undercrown Milling | No |
| Accumulator Groove | Yes |
| Anodize Top Ring Groove | No |
| Bore Diameter | 99.50 mm |
| Combo 2 | No |
| Compression Height | 28.70 mm |
| Compression Ratio | 8.50:1 |
| Connecting Rod Length | 130.50 mm |
| Contact Reduction | No |
| Country Of Origin | USA |
| Cylinder Head | EJ257 STI |
| Double Pin Oilers | No |
| DVGP | No |
| Econo Undercrown Milling | No |
| EN Plating | No |
| Engine | EJ257 |
| Engine Detail | 2004-2017 Impreza STI, 2005-2006 Outback XT/Legacy GT |
| Engine Displacement | 2457 |
| Engine Family | EJ Series |
| Engine Stroke | 3.268 in |
| Engine Type | ICE |
| Exhaust Angle | 22 |
| Exhaust Depth | .230 |
| Exhaust Diameter | 1.550 |
| Forging Type | FSR |
| Gas Distribution | No |
| Intake Angle | 22 |
| Intake Depth | .230 in |
| Intake Diameter | 1.550 in |
| Lateral Gas Ports | Yes |
| Make | Subaru |
| Mill Undercrown | No |
| OEM Bore Diameter | 99.50 mm |
| Oil Groove Width | 0.09950 in |
| Oversized | No |
| Oversized Amount | STD mm |
| Pin Fit | Yes |
| Piston Average Weight | 398 gr |
| Piston Head Type | Inv Dome/Dish |
| Piston Material | 2618 |
| Piston Quantity | 4 |
| Piston Series | JE Ultra Series |
| Piston To Wall Clearance | -0.004 in |
| Piston Volume | -20.70 cc |
| Product Market | Sport Compact |
| Product Type | Engine Piston Kit |
| Ring Quantity | 4 |
| Ring Set Included | Yes |
| Ring Set Part Number | JG4904-3917 |
| Ring Set Thickness | 1.20 MM x 1.20 MM x 2.50 MM |
| Skirt Coat | Yes |
| Smooth Crown Finish | Yes |
| Thermal Crown | Yes |
| Top Groove Width | 0.04750 in |
| 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 in |
| Wrist Pin Outer Diameter | 0.905 in |
| 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 |
30 Months
WARNING: This product can expose you to chemicals including nickel, which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.
California carb status to be completed
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