The Subaru EJ engine is a series of automotive engines manufactured by Subaru and introduced in 1989, intended to succeed the previous Subaru EA engine. The EJ series is the mainstay of Subaru's engine line, with all engines of this series being 16-valve flat-4 horizontal, with configurations available for single-, or double-overhead camshaft arrangements (SOHC or DOHC). Naturally aspirated and turbocharged versions are available, ranging from around 120 horsepower in early non-turbo Legacies, to 320 horsepower in the Impreza WRX STI. These engines are commonly used in light aircraft, kit cars and engine swaps into air-cooled Volkswagens, but it's also popular as a swap into thewasserboxer engined Volkswagen Type 2. 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
Usage:
Specifications
- Displacement: 1493 cc
- Bore: 85.0 mm
- Stroke: 65.8 mm
- Compression Ratio: 9.4:1 - 10.0
- Valvetrain: SOHC
- Fuel Delivery multi point fuel injection
- Horsepower: 970NaN0 @ 6000 rpm
- Torque: 129.40NaN0 @ 3600 rpm
- Horsepower: 1020NaN0 @ 5600 rpm
- Torque: 136.30NaN0 @ 4000 rpm
- Horsepower: 950NaN0 @ 5200 rpm
- Torque: 140.20NaN0 @ 3600 rpm
- Horsepower: 1000NaN0 @ 5200 rpm
- Torque: 1420NaN0 @ 4000 rpm
Usage:
Specifications
- Displacement: 1597 cc
- Bore: 87.9 mm
- Stroke: 65.8 mm
- Compression Ratio: 9.4:1 - 10.0:1
- Valvetrain: SOHC
- Fuel Delivery mpfi (carburetor in some locations)
- Horsepower: 1000NaN0 @ 6000 rpm
- Torque: 138.30NaN0 @ 4500 rpm
Usage:
- Impreza 93-99 GC6 series
- Legacy (except USA) 90-96 BC2, BC3, BD2, BD3, BG3 series
- Isuzu Aska (1990–1993)
- Displacement: 1820 cc
- Bore: 87.9 mm
- Stroke: 75.0 mm
- Compression Ratio: 9.5:1 - 9.7:1
- Valvetrain: SOHC
- Fuel Delivery single point fuel injection
- Horsepower: 1100NaN0 @ 6000 rpm
- Torque: 149.10NaN0 @ 3200 rpm
- Horsepower: 1150NaN0 @ 6000 rpm
- Torque: 1540NaN0 @ 4500 rpm
- Horsepower: 1200NaN0 @ 5600 rpm
- Torque: 163.80NaN0 @ 3600 rpm
(Japanese: [[:ja:スバル・EJ20|Subaru EJ20]])Specifications
- Displacement: 1994 cc
- Bore: 92.0 mm
- Stroke: 75.0 mm
EJ20E SOHC naturally aspirated
- Legacy JDM
- 1989-1994 125hp BC - BF series
- 1993-1999 135hp BD - BG series(ECU 3G)
- 1998-2004 155hp BE - BH series(ECU 3G)
- 2003-2009 140hp BL - BP series
- Impreza JDM
- 1993-1999 135hp GC - GF series
- 2008-current 140hp GH series
- Isuzu Aska (1990–1993)
- 1989-1994 125hp
EJ204 DOHC naturally aspirated AVCS
EJ20N runs on compressed natural gasEJ20 Turbocharged
All engines listed below were installed with a turbo and an intercoolerEJ20T
This is not actually a valid code from Subaru, but is mostly used by enthusiasts and also mechanics to describe the entire line of 2.0 litre turbochargedengines that have been available over time. The practice began with the incorrect 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 in to 3 categories:1. Rocker-style HLA EJ20G usage:
Power output ranges from 200 PS (147 kW; 197 bhp) @ 6000 rpm and 260 Nm for the GT to 220 PS (162 kW; 217 bhp) @ 6400 rpm and 270 Nm for the RS versions.Engines can be identified by coil on plug 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 (chargecooler) and Oil squirters.2. Bucket-style HLA EJ20G usage:
- Impreza WRX 92~96
- Impreza WRX Wagon 92~96
- Impreza WRX STI 93~96
- EUDM Subaru Impreza Turbo 94~96
- Impreza WRX AT 97~98
- Impreza WRX AT Wagon 97~98
- JDM Forester Turbo 97~98
- EUDM Subaru Impreza Turbo 97~98
to identify an EJ20K
- Wasted spark coil pack on center of manifold
- Inlet under manifold
- Divorced idle air controller
- Impreza WRX & STi 9/96~9/98
This engine series is used for non-Japanese marketed WRX models in the world market 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 use the EJ205, with an exception of the USDM models, which used the EJ205 until 2005. The EJ205 has a 8:1 compression ratio.To identify an EJ205:
- Coil on plug*
- idle air integrated into throttle body
- open deck block
- 99~01 (JDM Wagon Body only)
- 01~current (all JDM)including Forester Cross Sports and STI (9:1 compression ratio)
- 02~05 (USDM)
- 99~current (all other markets)
The EJ207 has a 8.0:1 compression ratio.To identify an 9/99-9/2000 EJ207
- Wasted spark coil pack off center of manifold
- Inlet under manifold
- Red intake manifold
- Semi-closed deck block
- Impreza WRX STi 1998~present (JDM, specifically Homologation models for World Rally Championship)
This can refer to one of the 2.0 Litre DOHC Sequential Twin Turbo and intercooled engines (EJ20H/EJ20R/EJ206/EJ208), yet like EJ20T, it is not actually a valid code used by Subaru themselves. Used from 1994 to 2005 in various iterations listed below. Due to the tight confines of the engine bay, the twin turbo engine was installed in Japanese-spec Legacies only, which were right-hand drive.EJ20H
Usage:
- 1993-1998 Legacy chassis code BD/BG5 JDM RS, RS-B and GT's (1830NaN0 manual & automatic) and auto RS-B and GT-B's (2060NaN0 automatic)
Usage:
EJ206
Usage:
EJ208
Usage:
EJ22
Usage:
Specifications
- Displacement: 2212 cc
- Bore: 96.9 mm
- Stroke: 75.0 mm
- Compression Ratio: 9.5:1 - 9.7:1
- Valvetrain: SOHC
- Fuel Delivery multi-point fuel injection
- Horsepower: 1350NaN0 @ 5800 rpm
- Torque: 186.30NaN0 @ 4800 rpm
- Horsepower: 1420NaN0 @ 5600 rpm
- Torque: 1490NaN0 @ 3600 rpm
Beginning in the 1997 Model Year, the 2.2 liter engine for 1997 Legacy and Impreza models has had internal and external changes that yield an approximately 10% increase in power and 3% increase in fuel economy.Accomplishing this involves many factors, one of which is engine friction reduction. The piston, a major source of engine friction, has been coated with molybdenum to reduce friction. This thin coating not only allows smoother travel through the cylinder, but also reduces cylinder wall scuffing.The skirt of the piston has been reshaped and the overall weight has been reduced by approximately 100 grams. Compression ratio has been increased to 9.7 to 1 by reshaping the crown of the piston. This eliminates the clearance that was available between the piston at TDC and the fully opened valve.Piston pin offset has been changed to 0.51NaN1. Piston to cylinder wall clearance has been reduced by increasing the piston diameter.Another source of high engine friction is the valve train. Hydraulic lash adjusters (HLAs) are always in contact with the valves. The hydraulic pressure of the lash adjuster must be overcome during operation and during the most critical time of engine start.To overcome this situation and to contribute to the total reduction of friction loss, 1997 and later SOHC engines have solid valve adjusters. The scheduled service of this valve train is set at 100000miles. SOHC engines now use an adjustment screw to adjust valve clearance.The roller rocker cam follower system that was introduced on the 1.8L Impreza engines, is installed on all 1995 model year and later 2.2 liter engines. The roller assemblies are not serviceable separately, but the rocker arms may be serviced as individual units.The carbon composition head gaskets with integrated o-rings are interchangeable from left to right on 1990 to 1994 N/A engines only.Other Engine Modifications (2.2L 1997) The intake manifold has been reshaped to increase the airflow mass and speed, contributing to improved low and mid engine speed operation. Components located on the intake manifold have been relocated as compared to the 1996 models. EGR Solenoid, Purge Control Solenoid, etc.1999 2.2 Liter Phase 2 Engine Enhancements (from endwrench article H-4 and H-6 service):All 2.2 liter engine for 1999 are the Phase 2 design. The 2.2 liter Phase 2 engines are a SOHC design, with a newly designed cylinder head. Changes in the 2.2 liter Phase 2 engines are as follows:
- The engine and transmission are fastened with six bolts and two studs.
- The thrust bearing has been moved to the number 5 position.
- The oil groove in the number 1 and 3 have been changed to supply additional lubrication to the crank journal.
- The cylinder head is a two-rocker shaft, solid type valve system with roller followers.
- The valves are positioned at a larger angle than previous model years. The intake valves are positioned 23 degrees off-center with the exhaust valves positioned 20 degrees off-center. Prior model year engines utilized a 15-degree positioning angle.
- Head gasket thickness is 0.72NaN2.
- The intake rocker arms are marked so they are correctly placed on the rocker shaft when servicing. An IN1 or IN2 will be embossed on each rocker arm. As viewed from the front of the engine the Number 1 intake valve of ach cylinder and the number 2 intake valve have an IN1 marked and IN2 arked rocker arm that mates with it. New IN1 rocker arms can also be identified by a Green painted mark on the top of the rocker arm. The IN2 rocker arms have a white mark. Proper positioning is maintained through the use of a wave washer located between the rocker shaft arm and rocker arm shaft support.
- The camshaft is secured to the cylinder head with the camcase. An oil passage in the cylinder head provides the passageway in the camcase with oil that leads to the intake rocker shaft. Oil from the camshaft is collected on the opposite side of the passageway leading to the intake rocker shaft to provide oil to the exhaust rocker shaft.
- The sparkplug pipe is pressed into the cylinder head and is not serviceable.
- Pistons on the 2.2 liter engines have a 0.51NaN1 offset with the engine having a compression ratio of 10.0 to 1. The horsepower has increased to 142hp @ 5600 rpm. Maximum torque is 149lbft @ 3600 rpm.
- Camshaft sprockets are constructed of a resin type material with a metal key pressed into the sprocket for maintaining proper sprocket to shaft orientation.
2.2 litre135bhp @ 5800 rpm140lb·ft @ 4800 rpmAustralian model - 100kW @ 6000 rpm189Nm @ 4800 rpmUsage:
EJ22T
Phase one 2.2 Liter SOHC Turbo, 1630NaN0 fully closed deck, oil squirters, no intercooler
- Legacy 1991-1994 (North American-spec)
Phase two 2.2 litre closed deck
- Displacement: 2212 cc
- Bore: 96.9 mm
- Stroke: 75.0 mm
- Compression Ratio: 8.0:1
- Valvetrain: DOHC
- Fuel Delivery multi point fuel injection
- Horsepower: 2800NaN0 @ 6000 rpm
- Torque: 362.80NaN0 @ 3200 rpm
- Impreza STi 22B GC8 series(JDM)
- Legacy STi BF7 and BFB series wagon (JDM)
- Displacement: 2457 cc
- Bore: 99.5 mm
- Stroke: 79.0 mm
- Compression Ratio: 9.5:1 - 10.0:1 Naturally Aspirated
- Compression Ratio: 8.0:1 - 9.5:1 Turbo
- Fuel Delivery multi point fuel injection
The EJ25D has demonstrated leaking head gasket issues on occasion. This was due to a design flaw of the OEM gaskets. Since the release of the EJ25D, an updated gasket is available that is not prone to failure. There were two variations of the EJ25D sold in the US market. The engine was introduced in 1996 in the Legacy 2.5GT, LSi, and Legacy Outback. That version of the engine used HLA heads, was recommended to be run on 91 octane fuel, had lower power and torque ratings than the later '97-99 EJ25D, and was only offered with an automatic transmission. In 1997 a revised engine was introduced that used heads with shimmed bucket lifters (versus the HLAs), was designed to run on 87 octane fuel, and was available with either a manual or automatic transmission.DOHC (1996) - SAE - 155hp @ 5600 rpm
140ftlbf at 2800 rpm
DOHC (1997–1999) - SAE - 165hp @ 5600 rpm
162ftlbf at 4000 rpmUsage
EJ251
The EJ251 has demonstrated externally leaking head gasket issues on occasion as the engine accumulates mileage over 100,000 miles (160,000 km). SOHC Intake volume is calculated by the use of a MAP sensor, unlike the EJ253 which uses a MAF sensor. Compression ratio is 10.0:1.Power ISO: 123kW @ 5600 RPM
226Nm @ 4000 rpmUsage:
- Impreza 2.5RS, 2.5TS 00-04 (US)
- Impreza Outback Sport 02-04 (US)
- Forester 00-04 (US)
- Legacy 00-04 (US)
- Outback 00-04 (US)
- Baja 03-05 (US)
SOHCPower ISO 115 kW (156 hp)Usage:
EJ253
SOHC - ISO 173hp @ 5600 rpm, 166ftlbf torque @ 4000 rpm. Intake volume is regulated by use of a MAF sensor, unlike the EJ251 which is regulated by aMAP sensor. I-Active valves (VVL intake side) on 06+ models.
- Impreza 99, 05+
- Legacy, Outback USA 05+
- Forester 99, 05+
- Baja 05+
- Saab 9-2x Linear 05, 06
SOHC 16-valve Power SAE 121 kW (165 hp), 2005–present - 175hp.Usage:
- Impreza RS 02~04
- Forester 04
- Legacy/Outback 02~04, 05-present
- Legacy Lancaster RHD 1999-2003
DOHC turbocharged, with sodium-filled valves originally designed for North American market, now sees usage in some European Imprezas and Legacies destined for Australia and South Africa. Power 210-265 hpUsage in North America:
- Impreza: 2006–present
- Forester: 2004–present
- Legacy: 2005–present
- Outback: 2005-2009
- Baja: 2004 - 2006
- 9-2X: 2006
EJ257
DOHC 16-valve turbo. Originally designed for the North American Impreza STI in 2004 with AVCS and DBW. The same exact shortblock as EJ255 except the EJ255 has a different domed piston vs the EJ257. The heads also have different components. Subaru of America designates the same part numbers for an EJ255 shortblock, and EJ257 shortblock with the exception of the pistons.Usage:
- US Market Impreza WRX STi MY04~MY07 (300 hp, 293 hp (New SAE standard))
- US Market Impreza WRX STI MY08~MY10 (305 hp (New SAE standard))
- US Market Subaru Legacy/Subaru Outback MY05~MY06
- Asian, European Market Impreza WRX STi 05~present (280 hp, 40KGh/m)
- JDM Forester STI MY05~present
In 1990, Subaru took over the Coloni Formula One team, acquiring a 51% ownership stake, paying off the team's debts, and supplying a new, unique engine. The engine was a flat-12 called the "MM" series, which in fact was penned by Carlo Chiti.Chiti's Motori Moderni company at Novara had supplied V6 turbo engines for the Minardi Formula One team from 1985 to 1987, and in 1988 Chiti had penned a normally aspirated V12 engine that attracted Subaru. In late 1988, the Japanese commissioned Chiti to design a new Formula One engine with a "flat" layout, as used in their road cars. The engine was completed in the summer of 1989, and was tested in a Minardi M188 chassis; due to a severe lack of power, Minardi lost interest. After a few months of searching, Subaru found the Coloni team. Eventually, the Subaru Coloni team was founded with Enzo Coloni staying on board as the man for operational business.By the beginning of 1990, the Subaru flat engine was not producing more than 500 bhp, so the Coloni Subaru was by far the least competitive machine regularly competing in Formula One in 1990. Subaru and Chiti agreed to build a new V12 engine for summer 1990 together with a completely new chassis, but in the meantime the flat engine should be used by the Coloni Subaru Team in a carry-over chassis. Early in 1990, a handful of Enzo Coloni's mechanics worked on a single C3 and tried to put the Subaru engine in it. The work was not done until the day the FIA started shipping the Formula One material toPhoenix. In the pits at Phoenix, the car was assembled for the very first time, and a short private practice took place on a parking area of an American supermarket. On prequalification day of Phoenix the world saw Coloni's new model C3B which wore a white, red, and green livery. Without an airbox but with wide, long sidepods, it looked unusual, was overweight by 300 pounds and nearly impossible to handle. Bertrand Gachot, Coloni's new driver, was unable to prequalify the car at Phoenix or at any other event. As the season went on, improvements were few and results stayed nowhere. Meanwhile, no success could be seen at Coloni's plant in Perugia where obviously nobody worked seriously on a new car. In May, Enzo Coloni was sacked by Subaru, but no improvement came. In June, the Japanese company withdrew completely and sold the team back to Enzo Coloni, debt free, but with no sponsors and no engines. By the German Grand Prix Coloni had arranged a supply of Cosworth engines, prepared by Langford & Peck. An improved car also appeared in Germany. The new Coloni C3C was simply a 1989 C3 with minor changes in aerodynamics. The car was quicker, but not enough to achieve any serious results. Gachot was usually able to prequalify his car, but the main qualification was still out of reach. By the end of the season, Coloni had not taken part in a single Grand Prix.Other Data
All the EJ series share compatibility and construction similarity and are 16 valved engines. The EJ series started with the EJ15, a 1.5 liter (SOHC) and makes ~90 hp, then the EJ16, a 1.6 litre single overhead cam (SOHC). Later followed by the EJ20, a 120 hp 2.0 litre single overhead cam and the EJ22, a 135 hp 2.2 litre single overhead cam. The EJ20 turbocharged version was developed with dual overhead cams, as well as non-turbo DOHC engines andDOHC twin-turbos. The EJ18 and EJ20 were most popular in Europe and the EJ22T SOHC, mostly in the US and is known as the "bulletproof Subaru engine."The SOHC EJ Subaru boxer engines were non-interference engines through 1996, run by a single timing belt driving both cams (both sides of the engine) and the water pump. Because they are non-interference engines, if the timing belt fails, the engine of the models up to 1996 will not be destroyed. The oil pump is driven directly from the crank shaft and the waterpump by the timing belt. All DOHC and 1997-up SOHC EJ engines are interference engines, if the timing belt fails the engine will likely be destroyed or the valves & piston will be heavily damaged.All Subaru EJ engines have a 1-3-2-4 firing order.Some of the 2005 and later Subaru vehicle Engines (especially the turbo charged engines) are using CAN (Controller Area Network) bus as their sole Vehicle/Vessel speed input channel, the CAN bus normally runs at 500K baud rate. When those ABS Speed signal are removed, the ECU will force the Engine running at limp home mode (engine cannot run over certain speed, maximum power and torque output are limited, and idle is not as stable as normal operation). This has posed some challenge for people who try to use the same automotive boxer 2.5L and 3.3L engines on Aerospace application, engine replacement for aged Subaru vehicles, and VW Vanagon modifications, etc.The following table has details on a few of the commonly modified Subaru engines:
| Block | EJ257 | EJ257 | EJ257 | EJ205 | EJ207 | |
| Head Type | US STI Heads | US WRX Heads | SpecC Heads | US WRX Heads | SpecC Heads | |
| Bore | (mm) | 99.50 | 99.50 | 99.50 | 92.00 | 92.00 |
| Crank Stroke | (mm) | 79.00 | 79.00 | 79.00 | 75.00 | 75.00 |
| Rod Length | (mm) | 130.43 | 130.43 | 130.43 | 130.43 | 130.43 |
| Piston Pin Offset | (mm) | 30.88 | 30.88 | 30.88 | 32.89 | 31.59 |
| Deck Height | (mm) | 201.00 | 201.00 | 201.00 | 201.00 | 201.00 |
| Gasket Thickness | (mm) | 0.80 | 0.80 | 0.80 | 0.80 | 0.80 |
| Head Volume | (cc) | 57.00 | 51.00 | 50.00 | 51.00 | 50.00 |
| Piston Dish | (cc) | 22.00 | 22.00 | 22.00 | 12.00 | 8.00 |
| Piston Deck | (mm) | 0.39 | 0.39 | 0.39 | 0.38 | 1.48 |
| Total Quench Height | (mm) | 0.99 | 0.99 | 0.99 | 0.98 | 2.08 |
| Total Quench Volume | (cc) | 7.70 | 7.70 | 7.70 | 8.51 | 13.83 |
| Total Deck Volume | 29.70 | 29.70 | 29.70 | 18.51 | 19.83 | |
| Swept Volume | (cc) | 614.28 | 614.28 | 614.28 | 498.57 | 498.57 |
| Compresses Volume | (cc) | 86.70 | 80.70 | 79.70 | 89.51 | 89.83 |
| Static CR | 1 | 8.09 | 8.61 | 8.71 | 8.17 | 8.14 |
| Rod to Stroke Ratio | (na) | 1.65 | 1.65 | 1.65 | 1.74 | 1.74 |
| Engine Displacement | (cc) | 2457.00 | 2457.00 | 2457.00 | 1994.00 | 1994.00 |
Subaru 2.5-liter Turbo Boxer Engine won 'best engine' in the 2.0-2.5 litre category in both the 2006 and 2008 International Engine of the Year awards.[SUP][1][/SUP]References
Source - http://everything.explained.today/Subaru_EJ_engine/
