Subaru EJ engine


The Subaru EJ engine is a series of four-stroke automotive engines manufactured by Subaru. Introduced in 1989, they were intended to succeed the previous Subaru EA engine. The EJ series was the mainstay of Subaru's engine line, with all engines of this series being 16-valve horizontal flat-fours, with configurations available for single, or double-overhead camshaft arrangements. Naturally aspirated and turbocharged versions are available, ranging from. These engines are commonly used in light aircraft, kit cars and engine swaps into air-cooled Volkswagens, and are also popular as a swap into Volkswagen T3/Vanagons powered by the Volkswagen Wasserboxer engine. Primary engineering on the EJ series was done by Masayuki Kodama, Takemasa Yamada and Shuji Sawafuji of Fuji Heavy Industries, Subaru's parent company.

EJ15 (1.5L Boxer NA)

Usage:
  • Impreza GC1 series — Replaced by Subaru EL engine in 2006 GD, GG, GE & GH series Impreza.
  • Impreza 93–06

    Specifications

  • Displacement:
  • Bore:
  • Stroke:
  • Compression Ratio: 9.4:1 – 10.0
  • Valvetrain: SOHC, 16 valves
  • Fuel Delivery multi point fuel injection
EJ151
  • Horsepower: at 6000 rpm
  • Torque: at 3600 rpm
EJ152
  • Horsepower: at 5600 rpm
  • Torque: at 4000 rpm
EJ153
  • Horsepower: at 5200 rpm
  • Torque: at 3600 rpm
EJ154
  • Horsepower: at 5200 rpm
  • Torque: at 4000 rpm

    EJ16 (1.6L Boxer NA)

Usage:
  • Impreza 93–94 GC4 series
  • Impreza 93–06
  • Impreza 93–97
  • Impreza 93–06

    Specifications

  • Displacement:
  • Bore:
  • Stroke:
  • Compression Ratio: 9.4:1 – 10.0:1
  • Valvetrain: SOHC Belt drive
  • Fuel Delivery mpfi
EJ16
  • Horsepower: at 6000 rpm
  • Torque: at 4500 rpm

    EJ18 (1.8L Boxer NA)

Usage:
  • Impreza 93–99 GC6 series
  • Legacy 90–96 BC2, BC3, BD2, BD3, BG3 series
  • Isuzu Aska

    Specifications

  • Displacement:
  • Bore:
  • Stroke:
  • Compression Ratio: 9.5:1 – 9.7:1
  • Valvetrain: SOHC
  • Fuel Delivery Carburetor + Distributor and single point fuel injection
EJ181
  • Horsepower: at 6000 rpm
  • Torque: at 3200 rpm
EJ182
  • Horsepower: at 6000 rpm
  • Torque: at 4500 rpm
EJ183
  • Horsepower: at 5600 rpm
  • Torque: at 3600 rpm

    EJ20 (2.0L Boxer Turbo/NA)

  • Bore:
  • Stroke:
At the 46th Tokyo Motor Show in October 2019, Subaru announced it would conclude production of the EJ20 by the end of March 2020. At that time, the EJ20 was only being sold in the Japanese domestic market for the WRX STI, and a special "WRX STI EJ20 Final Edition" with a balanced version of the engine was sold to commemorate the end of EJ20 production.

Naturally aspirated

EJ20E SOHC naturally aspirated
  • Legacy JDM
  • * 1989–1994 BC — BF series
  • * 1993–1999 BD — BG series
  • * 1998–2004 BE — BH series
  • * 2003–2009 BL — BP series
  • Impreza JDM
  • * 1993–1999 GC — GF series
  • * 2008–current GH — GE series
  • Isuzu Aska
  • * 1990–1993
EJ201 SOHC naturally aspirated
  • Bore:
  • Stroke:
  • MAP sensor
  • Forester SF and SG Series
  • * 2002–2005
  • GD/GG Impreza
  • * 2000–2005
  • GC/GF Impreza
  • BE/BH Legacy
EJ20D DOHC naturally aspirated
  • Legacy JDM
  • * 1989–1999 BC — BF and BD — BG series
EJ202 SOHC naturally aspirated
  • Forester JDM SF series, 138 PS
  • Forester JDM SG series, 137 PS, e.g. EJ202DXSAE x20
EJ203 SOHC naturally aspirated
  • Forester JDM SG series, 140 PS
  • Legacy JDM 2.0i BP/BL series, 140 PS
EJ204 DOHC naturally aspirated AVCS
  • Legacy B4 TSR JDM BE — BH series
  • * 1999–2001
  • Legacy JDM BL — BP series
  • * 2003–2009
  • Legacy BL — BP series
  • * 2003–2007
  • Impreza JDM GC — GF series
  • * 1993–1999
  • Impreza GE — GH series
  • * 2007–2011
  • Forester SG Series
  • * 2005–2007
  • Forester JDM SH Series
  • * 2008–2011
  • Exiga JDM YA Series
  • * 2008–2012
  • Legacy European and S. African Markets BM BR Series
  • * 2009–2014
EJ20C runs on compressed natural gas
All engines listed below were installed with a turbocharger and an intercooler:

EJ20T

Is not actually a valid code from Subaru, but is mostly used by enthusiasts and mechanics to describe the entire line of turbocharged engines that have been available over time. The practice began with the designation of the USA-spec turbo, commonly referred to as the EJ22T, and the habit of referring to any turbocharged engine as a "T" began. When referring to the EJ20T, one is speaking of one of the following:

EJ20G

EJ20G engines fall into 3 categories:
1. Rocker-style HLA EJ20G usage
  • Legacy RS 89–93
  • Legacy RS-RA 89–93
  • Legacy GT 89–93
Power output ranges from at 6000 rpm and for the GT to at 6400 rpm and for the RS versions.
Engines can be identified by coil on plug, and with 2 M6 bolts per coil and valve covers with 4CAM 16VALVE and horizontal lines above and below the plug holes. All these engines have the air-to-water intercooler setup and close deck blocks equipped with piston oil squirters.
2. Bucket-style HLA EJ20G usage
This updated type of EJ20G was used in all WRX models since early 1992, cylinder head is equipped with hydraulic lifters compared
to the rocker arms used in the previous EJ20G. Pistons in this type of EJ20G are all cast aluminum. Closed-deck engine block equipped with
piston oil squirters was used until mid 1994. Followed by Open-deck block equipped with piston oil squirters was used very short period of time, Followed by Open-deck block from 1995 until mid 1996 when the first EJ20K WRX engines came out. The open deck block on all EJ20G could be identified by a smoother surface, and a tab on the right surface of the block halves. The EJ20G continued to be used in the WRX Wagon with an Automatic Transmission from 1996 till 1998 when it was replaced by the EJ205.
  • Closed deck:
  • EJ20GDW1HD 1992-05-01 to 1993-08-31 WRX.EJ20G
  • EJ20GDW1HE 1992-05-01 to 1993-08-31 WRX.EJ20G
  • EJ20GDW1HJ 1992-05-01 to 1993-08-31 WRXRA.EJ20G
  • EJ20GDW1HR 1992-05-01 to 1993-08-31 WRXRA.EJ20G
  • EJ20GDW2HD 1993-05-01 to 1994-09-30 S.WRX.MT.EJ20G
  • EJ20GDW2HE 1993-05-01 to 1994-09-30 S.WRX.MT.EJ20G
  • EJ20GDW2HJ 1993-05-01 to 1994-09-30 WRXRA.EJ20G
  • EJ20GDW2HR 1993-05-01 to 1994-09-30 WRXRA.EJ20G
  • EJ20GDW4HJ 1993-06-01 to 1995-08-31 WRXRA.EJ20G
  • EJ20GDW5HJ 1995-09-01 to 1996-08-31 WRXRA.EJ20G
  • Open deck:
  • EJ20GDX1ND 1993-05-01 to 1994-09-30 AT.EJ20G
  • EJ20GDX1NE 1993-05-01 to 1994-09-30 AT.EJ20G
  • EJ20GDW1ND 1993-05-01 to 1994-09-30 W.MT.EJ20G
  • EJ20GDW1NE 1993-05-01 to 1994-09-30 W.MT.EJ20G
  • EJ20GDW4HD 1994-06-01 to 1995-08-31 S.WRX.EJ20G
  • EJ20GDW4HE 1994-06-01 to 1995-08-31 S.WRX.EJ20G
  • EJ20GDW4ND 1994-06-01 to 1995-08-31 W.WRX.MT.EJ20G
  • EJ20GDW4NE 1994-06-01 to 1995-08-31 W.WRX.MT.EJ20G
  • EJ20GDX4NE 1994-06-01 to 1995-08-31 WRX.AT.EJ20G
  • EJ20GDW5HE 1995-09-01 to 1996-08-31 S.WRX.EJ20G
  • EJ20GDW5NE 1995-09-01 to 1996-08-31 W.WRX.MT.EJ20G
  • EJ20GDX5NE 1995-09-01 to 1996-08-31 AT.EJ20G
  • EJ20GDX5HD 1995-09-01 to 1996-08-31 S.WRX.EJ20G
  • EJ20GDW5PE 1995-10-01 to 1996-08-31 W.WRX.MT.EJ20G
  • EJ20GDW5PE 1995-10-01 to 1996-08-31 WRXSTI.EJ20G
  • EJ20GDW5PJ 1995-10-01 to 1996-08-31 WRXRASTI.EJ20G
    3. Shim-under-bucket style EJ20G usage
All EJ20G equipped Impreza WRX STI RA.
Power output ranges from at 6000 rpm for the WRX Wagons to at 6500 rpm for the WRX STI Version II.
Engines can be identified by coil on plug with 1 M8 bolt per coil and valve covers with 4CAM 16VALVE and horizontal lines above the plug holes. Generally these engines all have the slanted intercooler. Engines from the STI RAs received the upgraded Shim-Under-bucket style lifters unlike the normal HLA buckets the WRX & the WRX STI had. These engines also feature STI factory 8.5:1 forged pistons, lighter valves, the intake valves are marked INKO and the exhaust valves are marked EXKO. The standard HLA valves are I252 and E283 respectively. All WRX Wagon engines and automatic sedan engines came with a TD04 with 90 deg elbow, all manual WRX sedans including STI versions had a TD05 with 90 deg elbow.
EJ20J SOHC naturally aspirated
  • JDM Forester SF5 S/20 135 ps

    EJ20K

EJ20K engines fall into 2 categories:
1. Shim-over-bucket style EJ20K usage (late EJ20G)
  • JDM WRX 96~97
  • Impreza WRX wagon MT 97~98
  • Impreza WRX type RA or R MT 97~98
  • SF5 Forester
    2. Shim-under-bucket style EJ20K usage
  • Impreza WRX STI MT 96~98
  • Impreza WRX STI wagon MT 96~98
  • Impreza WRX STI type RA or R MT 96~98
Power output is at 6800 RPM for the Japanese versions and for the v3 STI with VF23 turbo.
These engines can be identified by smooth valve covers, plug leads and a wasted spark coil in the middle of the intake manifold. In addition, the inlet manifold may be bare aluminum for all WRX models and red for all STI models. The engine utilizes an IHI ball-bearing turbo unit. VF22 on the WRX, either a VF23 or VF24 on the STI. These engines have die-cast pistons for all WRX models, STI and STI typeRA/STI type R models shares exactly the same factory forged pistons.

EJ205

This engine series is used for WRX models in the world market outside Japan as of 1999. The Japanese WRX models use the EJ207 from 1999~2001, except the 5-door wagon which also uses the EJ205. After 2001, all WRXs used the EJ205, until 2006 when the USDM WRX model changed engines to the EJ255. The EJ205 has an 8:1–9:1 compression ratio.
To identify an EJ205:
  • Coil on plug, except in JDM SF5 forester.
  • idle air integrated into throttle body
  • inlet under manifold
  • open deck block
Usage:
Impreza WRX
  • 99~01
  • 01~06
  • 02~05
  • 05 SAAB 9-2X AERO
  • 99~06
Forester Cross Sports, S/tb, STI
  • Late 99–01
  • 2003, at 5500 rpm
NOTE: The Australian Spec MY00 EJ205 does not have coil on plug but can be identified from the VIN of the vehicle where the tenth digit will be Y and the sixth digit will be 8