Hubbry Logo
Subaru six-cylinder enginesSubaru six-cylinder enginesMain
Open search
Subaru six-cylinder engines
Community hub
Subaru six-cylinder engines
logo
7 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Subaru six-cylinder engines
Subaru six-cylinder engines
Subaru six-cylinder engines
View on Wikipedia
from Wikipedia

The Subaru six-cylinder engines are a series of flat-6 engines manufactured by Subaru, made in three distinct generations. The ER27, derived from the Subaru EA first-generation flat-4, was used as the sole engine option in the premium model 1988–91 Subaru Alcyone VX (XT6 in the United States). The EG33, derived from the Subaru EJ second-generation flat-4, was used exclusively in the successor Subaru Alcyone SVX, again as its sole engine option, sold from 1991–96. The EZ series, consisting of the EZ30 and EZ36 models, was designed to be almost as compact as the EJ25 flat-4. The EZ30/36 were the first Subaru six-cylinder engines available outside the sport coupes, used as the uplevel option for Subaru Legacy (2002–19) and Outback/Lancaster (2001–19) as well as the sole option in the Subaru Tribeca (2006–14).

ER27

[edit]
Subaru ER27
Overview
ManufacturerSubaru
Production1988–1991
Layout
Configurationflat-6 petrol engine
Displacement2.7 L: 2,672 cc (163.1 cu in)
Cylinder bore92 mm
Piston stroke67 mm
Cylinder block materialaluminium
Cylinder head materialaluminium
ValvetrainSOHC
Compression ratio9.5:1
Combustion
Fuel typePetrol/gasoline
Output
Power output112 kW (150 hp; 152 PS) @5200 RPM[1]
Torque output211 N⋅m (156 lb⋅ft) @4000 RPM[1]
Chronology
SuccessorEG33
Subaru Alcyone VX

Created as a refined luxury engine with improved power over the EA82T, Subaru introduced the ER27 engine in November 1985 for the Subaru ACX-II concept car, shown at the Tokyo Motor Show and billed as the 'concept car of the near future.'[2] The concept went into production as the Subaru Alcyone VX (Subaru XT6 in North America) in August 1987,[3] the exclusive application for the ER27.

When the ER27 was introduced, it was the only water-cooled flat-6 automobile engine on the market.[4] The ER27 designation was the first time Subaru incorporated the engine's displacement into the engine designation and all subsequent engine codes have retained this nomenclature.

Design

[edit]

Like the EA series engines, the ER27 engine featured two valves per cylinder heads (six valves per cylinder head) with hydraulic lash adjusters and the ER27 and EA engines shared the same bore, stroke, and spacing. While recognised as bearing many similarities to the Subaru EA82 engine, there are numerous differences in design between the two engines and a large portion of parts are unique to the ER27. For instance, the oil and water pumps are unique to the ER27,[5][6] sharing similar bolt patterns and design to the EA82,[7][8] but being of a higher flow in both cases.[9]

The intake manifold uses a two-piece design with a lower section bolting to the heads containing the coolant bridge, injectors and various vacuum lines.[10] The upper intake manifold then bolts to the lower section and is unlike the EA82 or EJ22 "spider" manifold designs in that there is no central plenum chamber.[11]

The valve timing system is belt-drive using two individual timing belts, curiously one belt uses a spring tensioner (like the EA82) whilst the other uses a hydraulic tensioner (like the EJ22).[12]

Both JDM and USDM versions of the ER27 used multi-point electronic fuel injection. In North America, the ER27 was slightly derated to 145 hp (108 kW; 147 PS) at 5,200 RPM and 156 ft⋅lb (212 N⋅m) at 4,000 RPM.[4]

EG33

[edit]
Subaru EG33
Overview
ManufacturerSubaru
Production1991–1996
Layout
Configurationflat-6 petrol engine
Displacement3.3 L: 3,318 cc (202.5 cu in)
Cylinder bore96.9 mm
Piston stroke75 mm
Cylinder block materialaluminium, cast-iron cylinder liners
Cylinder head materialaluminium
ValvetrainDOHC
Compression ratio10.0:1
Combustion
Fuel typePetrol/gasoline
Output
Power output179 kW (240 hp; 243 PS) @6000 RPM[1]
Torque output309 N⋅m (228 lb⋅ft) @4000 RPM[1]
Chronology
Successor
  • EZ30
  • EZ36
Subaru Alcyone SVX

Similar to how the six-cylinder ER27 is related to the earlier four-cylinder EA82, the EG33 shared bore and stroke dimensions with the contemporary four-cylinder EJ22.[1] The EG33 was exclusively fitted to the Alcyone SVX, where it was paired with the 4EAT automatic transmission in both front- and all-wheel-drive configurations.[13]

After the SVX was discontinued, Subaru did not offer a six-cylinder engine until the EZ30 was developed and released for the Subaru Outback.

Design

[edit]

Unlike the SOHC EJ22 it shared some dimensions with, the EG33 featured dual overhead cams; both engines used four valves per cylinder.[14] The EG33 used a single toothed timing belt which drove the exhaust camshafts on each bank in addition to the water pump (mounted on the right bank); the intake camshaft on each cylinder bank was driven in turn by a set of helical gears via the belt-driven exhaust camshaft.[15][16][17]

At the time, the EG33 was the largest naturally aspirated engine that Subaru had ever made for regular production;[1][18] in the 1990s, Subaru branded the Subaru 1235, a 3.5 L flat-12 engine designed by Carlo Chiti and Motori Moderni, intended for Formula 1 racing, although Christian von Koenigsegg reportedly was later interested in the engine for his supercar.[19]

EZ30 and EZ36

[edit]
Subaru EZ engine
Overview
ManufacturerSubaru
Production
  • 2001–2009 (EZ30)
  • 2007–2019 (EZ36)
Layout
Configurationflat-6 petrol engine
Displacement
  • 3.0 L (EZ30): 2,999 cc (183.0 cu in)
  • 3.6 L (EZ36): 3,629 cc (221.5 cu in)
Cylinder bore
  • 89.2 mm (EZ30)
  • 92 mm (EZ36)
Piston stroke
  • 80 mm (EZ30)
  • 91 mm (EZ36)
Cylinder block materialaluminium
Cylinder head materialaluminium
ValvetrainDOHC
Compression ratio
  • 10.7:1 (EZ30)
  • 10.5:1 (EZ36)
Combustion
Fuel typePetrol/gasoline
Output
Power output
  • 162 kW (217 hp; 220 PS) @6000 RPM (EZ30)[20]
  • 180 kW (241 hp; 245 PS) @6600 RPM (EZ30 II)[21]
  • 191 kW (256 hp; 260 PS) @6000 RPM (EZ36)[22][23]
Torque output
  • 289 N⋅m (213 lb⋅ft) @4400 RPM (EZ30)[20]
  • 297 N⋅m (219 lb⋅ft) @4200 RPM (EZ30 II)[24]
  • 335 N⋅m (247 lb⋅ft) @4400 RPM (EZ36)[22][23]
Chronology
PredecessorEG33
SuccessorFA24F
Subaru Outback H6-3.0 (BH)

In the United States, the EZ30 was introduced in the Outback H6-3.0 in November 2000 for the 2001 model year.[25][26] In Japan, the EZ30 was introduced in the equivalent Lancaster 6 wagon in May 2000.[27] A twin-turbo version of the EZ30 was produced for the Subaru B11S concept car, unveiled at Geneva in 2003.[28] The EZ30 was refreshed in 2003, and when the Tribeca was introduced for the 2006 model year in January 2005, the EZ30 II was the sole engine option.[29]

The EZ36 was introduced with the restyled Tribeca for the 2008 model year,[30] and replaced the 3.0 L EZ30 in the Legacy and Outback starting in 2009 for the 2010 model year.[31][32]

Starting with the 2020 model year, the six-cylinder EZ36 was dropped as the uplevel engine option for Subaru Legacy and Outback automobiles and instead the premium engine offered was the turbocharged four-cylinder FA24F, which was previously introduced for the 2019 model year as the sole engine option for the Subaru Ascent, the successor to the Tribeca.

EZ series application
Engine Legacy / Outback Tribeca Power Torque
EZ30D mk I 2000–04 Outback H6 N/A 162 kW
217 hp; 220 PS
@ 6,000 RPM[20] 		289 N⋅m
213 lb⋅ft
@ 4,400 RPM[20]
2000–03 Lancaster 6
2002–03 GT30
2002–03 RS30
EZ30 Turbo —[a] 294 kW
394 hp; 400 PS
@ 6,400 RPM[28] 		550 N⋅m
410 lb⋅ft
@ 3,600 RPM[b][28]
EZ30D mk II[c] 2004–09 3.0R 2006–07 (all) 180 kW
241 hp; 245 PS
@ 6,600 RPM[21][33] 		297 N⋅m
219 lb⋅ft
@ 4,200 RPM[33][34]
EZ36D 2010–19 3.6R 2008–14 (all) 191 kW; 260 PS
256 hp
@ 6,000 RPM[23] 		335 N⋅m
247 lb⋅ft
@ 4,400 RPM[23]
Notes
  1. ^ Fitted to 2003 concept Subaru B11S only, never produced in volume.
  2. ^ Torque peak between 3,600 and 4,800 RPM.
  3. ^ Sometimes misidentified as "EZ30R". Subaru never designated an engine with this code. Revisions include the addition of variable valve timing (intake) and three exhaust ports per cylinder head.

Design

[edit]

EZ30D mk I

[edit]

The design of the EZ30 is credited to Noriaki Sekine.[35] Unlike prior Subaru flat-6 designs, the EZ30 has a significantly smaller bore pitch (the distance between adjacent cylinder centerlines on each bank of the engine block) than the contemporary flat-4 EJ-series. The bore pitch of the EZ30 is 98.4 mm (3.87 in),[36] compared to a bore pitch of 113 mm (4.4 in) in the EJ series.[37][38] The EZ30 also used a timing chain to drive the camshaft, while the earlier flat-4 EJ series uses a timing belt instead. These changes resulted in a more compact block; the external dimensions of the EZ30 are similar to the EJ25 four-cylinder engine, with length increasing by less than 1 inch (2.5 cm),[35] allowing for easier fitment in existing vehicles.[39][40]

A butterfly valve in the intake manifold opened at higher engine speeds, shortening the intake length and providing a passive supercharging effect through resonance.[20] The exhaust was also equipped with a valve which opened at high backpressure, increasing the effective muffler volume.[25]

In North America, the EZ30 was derated slightly to 158 kW; 215 PS (212 hp) and 280 N⋅m (210 lb⋅ft).[41]

In Europe a few EZ30 turbo engines went in the Outback station car. These cars are hard to find and very collectable.[citation needed]

EZ30D mk II

[edit]
Cutaway of switching tappet for Subaru AVLS fitted to EZ30D mk II

For the 2004 model year, the EZ30 was revised to add the Subaru active valve lift system to the intake cam, a system similar to Porsche's VarioCam, providing both variable valve timing and lift for the intake valves, which resulted in increased power, torque, and economy.[33][42] The cylinder heads for the EZ30D mk II were also revised to include three exhaust ports per head[43] instead of the single exhaust port used in the original EZ30D mk I, which gathered the exhaust from each cylinder bank into a single port.[44][41] Other detail improvements included a new block casting and a reduction in overall weight by 8.91 kg (19.6 lb), achieved through the use of hollow-journal camshafts, reducing the number of bolts in the timing chain cover, and switching to a plastic intake manifold.[41]

EZ36

[edit]

Compared to the EZ30, the EZ36 has larger bore and stroke; the EZ36 uses slightly thinner iron cylinder sleeves to increase bore, and uses asymmetric connecting rods to allow for an increase in stroke. A change to the cam drive resulted in an engine that was slightly longer than the preceding EZ30 by 0.83 in (21 mm), but maintained the same width.[45] A revised cooling system and variable valve timing (AVCS was now fitted to both intake and exhaust valves) allowed the EZ36 to run on regular unleaded fuel, instead of the premium unleaded required by the EZ30.[42][45]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Subaru six-cylinder engines

View on Grokipedia
from Grokipedia
Subaru six-cylinder engines are a family of horizontally opposed flat-six boxer engines produced by , characterized by their low center of gravity, inherent balance, and integration with the company's signature all-wheel-drive systems. Introduced in the late , these engines span three main generations—ER, EG, and EZ—offering displacements from 2.7 liters to 3.6 liters, with power outputs ranging from approximately 145 horsepower to 256 horsepower, and have powered premium and performance-oriented Subaru models including the Alcyone XT6, Alcyone SVX, Legacy, , and from 1988 to 2019. The first generation, the ER27, debuted in 1988 as a 2.7-liter (2,672 cc) single overhead (SOHC) engine with a 92 mm bore and 67 mm , producing 145 horsepower at 5,200 rpm and 156 lb-ft of at 4,000 rpm in North American specifications, and was exclusively fitted to the premium Alcyone XT6 coupe for enhanced smoothness over the brand's typical flat-four engines. The second generation, the EG33, arrived in 1991 as a 3.3-liter (3,318 cc) dual overhead (DOHC) 24-valve unit with a 10:1 , delivering up to 230 horsepower at 5,400 rpm and 228 lb-ft of at 4,400 rpm, and powered the upscale Alcyone SVX until 1996, noted for its refined performance and distinctive exhaust note. Subaru reintroduced six-cylinder power in 2000 with the third-generation EZ series, starting with the EZ30—a 3.0-liter (2,999 cc) DOHC featuring a 89.2 mm bore, 80 mm , and 10.7:1 , initially producing 206 horsepower at 6,000 rpm and 210 lb-ft of at 4,400 rpm in early applications like the H6. The EZ30 evolved into the EZ30R variant in 2002, incorporating (AVCS) and for improved efficiency, boosting output to 245 horsepower at 6,600 rpm and 219 lb-ft at 4,200 rpm in some markets. The larger EZ36, introduced in 2007 with a 3.6-liter (3,629 cc) displacement via a 92 mm bore and 91 mm , offered 256 horsepower at 6,000 rpm and 247 lb-ft of at 4,400 rpm at a 10.5:1 , and became the standard for upscale trims in the Legacy, , and until its discontinuation in 2019, replaced by more efficient turbocharged flat-four amid shifting emissions and fuel economy demands. These , all naturally aspirated and paired with automatic transmissions in production vehicles, emphasized Subaru's engineering focus on boxer layouts for superior handling and vibration reduction, though they were limited to higher-end models due to cost and complexity.

Overview

Historical context

Subaru's engine development has long been rooted in the boxer configuration, originating with the flat-four debut in the 1966 Subaru 1000, which prioritized inherent balance and a low center of gravity for superior handling stability. This horizontally opposed layout, designed by engineer Shinroku Momose to meet compact dimensional and performance needs, set the foundation for Subaru's subsequent flat-six engines by enabling a low-profile powerplant that enhanced vehicle dynamics without compromising packaging efficiency. The company's first flat-six, the ER27, emerged in 1988 for the XT6 coupe, building directly on the 1985 ACX-II concept that introduced a horizontally opposed six-cylinder with full-time at the Tokyo Motor Show. Intended as a refined alternative to the four-cylinder EA82T, the ER27 emphasized luxury-oriented power delivery and reliability to position the XT series against premium sports coupes. Subaru advanced this lineage in 1991 with the EG33 for the SVX sports coupe, focusing on elevated performance through a larger-displacement flat-six integrated with variable torque distribution all-wheel drive for optimized traction. By 1999, the EZ30 initiated the EZ series, supplanting the EG33 to comply with tightening emissions regulations and boost fuel efficiency, thereby broadening deployment into sedans like the Legacy and SUVs including the . The EZ36 followed in 2007 as an enlarged variant of the EZ30, providing greater power output for upscale applications such as the while retaining the boxer architecture. Production of Subaru's six-cylinder engines concluded around 2019, as the brand pivoted to turbocharged four-cylinder units to align with evolving efficiency standards and reduced displacement demands.

Common design principles

Subaru's six-cylinder engines universally adopt a horizontally opposed boxer configuration, with three cylinders arranged per bank in a flat-six layout. This design achieves inherent primary and secondary balance by having opposing pistons move symmetrically, minimizing vibrations without the need for additional balancing shafts, while the low engine height contributes to a reduced center of gravity, enhancing vehicle stability and handling when integrated with Subaru's Symmetrical All-Wheel Drive system. The boxer arrangement also allows for optimized engine mounting that aligns longitudinally with the drivetrain, promoting balanced weight distribution in all-wheel-drive applications. Construction across the ER27, EG33, EZ30, and EZ36 models features aluminum alloy blocks and heads, enabling substantial weight savings compared to cast-iron alternatives while providing adequate strength for performance demands; the ER27 block, for instance, incorporates cast-iron liners within the aluminum structure for durability. architecture evolves from the single overhead (SOHC) setup in the ER27, which uses two valves per , to dual overhead (DOHC) systems with four valves per in the EG33, EZ30, and EZ36, facilitating improved and exhaust flow for enhanced . Fuel delivery is managed via multi-point electronic in all variants, ensuring precise metering to each for optimal . Ignition systems progress from a distributor-based setup in the ER27 to individual coil-on-plug configurations in the EZ30 and EZ36 series, allowing for more accurate timing and reduced maintenance. All engines are liquid-cooled with a pressurized surrounding the and heads, complemented by a shared oil pan in layout that accommodates the horizontal orientation and ensures consistent lubrication under varying lateral accelerations.

ER27 engine

Design and specifications

The Subaru ER27 is a naturally aspirated, water-cooled with an aluminum cylinder block and heads. It has a displacement of 2,672 cc, achieved through a bore of 92.0 mm and a of 67.0 mm. The engine uses a single overhead (SOHC) design with 12 valves (two per cylinder) and hydraulic lash adjusters. The is 9.5:1, supported by multi-point electronic and a ignition system. The ER27, derived from the EA-series flat-four engines, features a belt-driven with one timing belt, a two-piece manifold without a central plenum, and unique higher-flow oil and water pumps. It produces 145 hp (108 kW; 147 PS) at 5,200 rpm and 156 lb⋅ft (212 N⋅m) of at 4,000 rpm in North American specifications, with slightly higher outputs of 150 PS in other markets. The weighs approximately 150 kg dry.
SpecificationDetails
Displacement2,672 cc
Bore × Stroke92.0 mm × 67.0 mm
ValvetrainSOHC, 12-valve
Compression Ratio9.5:1
Power Output145 hp (108 kW; 147 PS) @ 5,200 rpm
Torque Output156 lb⋅ft (212 N⋅m) @ 4,000 rpm
Fuel SystemMulti-point electronic injection
Block/HeadsAluminum
Produced from 1988 to 1991, the ER27 was Subaru's first production flat-six engine, emphasizing smoothness and balance over the flat-four lineup.

Applications and production

The Subaru ER27 engine was exclusively fitted to the premium Subaru Alcyone VX coupe (known as the XT6 in ) from 1988 to 1991, available in both front-wheel-drive and all-wheel-drive configurations. It served as the upscale powerplant for this model, providing refined performance and a low center of gravity characteristic of Subaru's boxer layout. Production of the ER27 occurred at Subaru's facilities in from 1988 to 1991, aligning with the XT6's model run, after debuting in the 1987 Alcyone concept. The engine was paired with automatic transmissions and was not offered in other models, marking Subaru's initial foray into six-cylinder power for higher-end vehicles. Its discontinuation coincided with the end of XT6 production, paving the way for the next-generation EG33 in the Alcyone SVX.

EG33 engine

Design and specifications

The Subaru EG33 is a naturally aspirated, water-cooled flat-six engine featuring an aluminum alloy cylinder block with cast-iron liners and aluminum cylinder heads. It has a displacement of 3,318 cc, achieved through a bore of 96.9 mm and a stroke of 75.0 mm. The engine employs a double overhead camshaft (DOHC) design with 24 valves (four per cylinder) and a 10:1 compression ratio, supported by multi-point electronic fuel injection and a timing belt for camshaft drive. Key features of the EG33 include its pentroof combustion chambers with center plugs for efficient burning, an open-deck cylinder block for improved cooling and rigidity, and a supported by seven main bearings. It produces 230 hp (172 kW; 233 PS) at 5,600 rpm and 228 lb⋅ft (309 N⋅m) of at 4,800 rpm in North American specifications. The engine weighs approximately 113 kg (250 lbs) for the long block.
SpecificationDetails
Displacement3,318 cc
Bore × Stroke96.9 mm × 75.0 mm
ValvetrainDOHC, 24-valve
Compression Ratio10:1
Power Output230 hp (172 kW; 233 PS) @ 5,600 rpm
Torque Output228 lb⋅ft (309 N⋅m) @ 4,800 rpm
Fuel SystemMulti-point electronic injection
Block/HeadsAluminum alloy with cast-iron liners
Produced from 1991 to 1996, the EG33 had no major variants and was designed exclusively for the Alcyone SVX.

Applications and production

The Subaru EG33 engine powered the Alcyone SVX from 1991 to 1996, available in markets including , , and . It was paired with a four-speed and Subaru's all-wheel-drive system, emphasizing refined performance and a distinctive exhaust note in the upscale coupe. As Subaru's first production DOHC flat-six, the EG33 provided smooth operation and balance inherent to the boxer layout, with power output varying slightly by market (e.g., up to 240 PS in some Japanese specifications). Production took place at Subaru's Gunma plant in , aligning with the SVX's model run until its discontinuation in 1996. The engine was not used in other models, marking a brief foray into six-cylinder power before the EZ series revival in 2000.

EZ30 engine

Design and specifications

The Subaru EZ30 is a naturally aspirated, water-cooled featuring an aluminum cylinder block with 2 mm thick cast-iron sleeves and aluminum cylinder heads. It has a displacement of 2,999 cc, achieved through a bore of 89.2 mm and a of 80 mm. The engine employs a double overhead (DOHC) design with 24 valves (four per cylinder). The is 10.7:1, supported by a multi-point electronic system and timing chains for reliable operation. The EZ30 was produced in two main variants: the initial EZ30D (2000–2004) without , and the updated EZ30R (2005–2009) incorporating Dual Active Valve Control System (AVCS) on intake and exhaust camshafts, along with Active Valve Lift System (AVLS) for improved efficiency and performance. The EZ30D complied with Euro 3 emission standards, while the EZ30R complied with Euro 4 emission standards. The EZ30D produces 206 horsepower (154 kW; 209 PS) at 6,000 rpm and 210 lb⋅ft (285 N⋅m) of at 4,400 rpm in North American specifications, while the EZ30R boosts output to 245 horsepower (183 kW; 248 PS) at 6,600 rpm and 219 lb⋅ft (297 N⋅m) at 4,200 rpm. The engine weighs approximately 180 kg (397 lbs) dry.
SpecificationDetails
Displacement2,999 cc
Bore × Stroke89.2 mm × 80 mm
ValvetrainDOHC, 24-valve (Dual AVCS and AVLS on EZ30R)
Compression Ratio10.7:1
Power Output206 hp (154 kW; 209 PS) @ 6,000 rpm (EZ30D); 245 hp (183 kW; 248 PS) @ 6,600 rpm (EZ30R)
Torque Output210 lb⋅ft (285 N⋅m) @ 4,400 rpm (EZ30D); 219 lb⋅ft (297 N⋅m) @ 4,200 rpm (EZ30R)
Fuel SystemMulti-point electronic injection
Block/HeadsAluminum with cast-iron sleeves
Produced from 1999 to 2009, the EZ30 emphasized Subaru's boxer layout for balance and low center of gravity, though it was prone to timing chain tensioner wear and occasional overheating if maintenance is neglected.

Applications and production

The Subaru EZ30 engine powered premium models in Subaru's lineup, primarily in North American and select other markets. It debuted in the 2000 Outback H6 wagon, continuing through the 2004 model year. The updated EZ30R variant was used in the 2005–2009 Legacy and Outback 3.0R trims, providing smooth performance for these mid-size sedans and wagons. Additionally, the EZ30 powered the 2006–2007 Tribeca SUV before the switch to the larger EZ36. As Subaru's return to six-cylinder power after the EG33, the EZ30 offered refined operation and all-wheel-drive integration, with towing capacity up to 2,700 pounds in applications. Production occurred at Subaru's Gunma Oizumi Plant in from 1999 to 2009. The engine's production ended as Subaru expanded the EZ series with the 3.6L EZ36 for larger , aligning with demands for more power in upscale trims. With proper , EZ30 engines are known for exceeding 200,000 miles, though they consume more than contemporary flat-four options.

EZ36 engine

Design and specifications

The Subaru EZ36 is a naturally aspirated, water-cooled featuring an aluminum block with 1.5 mm thick cast-iron sleeves and aluminum heads. It has a displacement of 3,629 cc, achieved through a bore of 92.0 mm and a stroke of 91.0 mm, representing an increase from the predecessor EZ30's dimensions to provide greater low-end . The employs a double overhead (DOHC) design with 24 valves (four per ) and Dual Active Valve Control System (AVCS) on both and exhaust s, offering 51° advance on and 21° on exhaust for optimized performance across the rev range. The is 10.5:1, supported by a multi-point electronic system and three timing chains for reliable operation. Key innovations in the EZ36 include its enlarged displacement and refined , which enhance delivery compared to the EZ30 while maintaining the compact boxer layout. It produces 256 hp (191 kW; 260 PS) at 6,000 rpm and 247 lb⋅ft (335 N⋅m) of at 4,400 rpm, with a redesigned cooling system to handle demands in larger vehicle applications. Asymmetric connecting rods measuring 125 mm contribute to the increased , and modified chambers improve efficiency. The engine weighs approximately 182 kg (401 lbs) dry.
SpecificationDetails
Displacement3,629 cc
Bore × Stroke92.0 mm × 91.0 mm
ValvetrainDOHC, 24-valve with Dual AVCS
Compression Ratio10.5:1
Power Output256 hp (191 kW; 260 PS) @ 6,000 rpm
Torque Output247 lb⋅ft (335 N⋅m) @ 4,400 rpm
Fuel SystemMulti-point electronic injection
Block/HeadsAluminum with cast-iron sleeves
Produced from 2007 to 2019, the EZ36 was offered in variants such as the EZ36D, which featured a strengthened cylinder block for enhanced durability; later revisions (sometimes denoted EZ36R) shared the same core specifications and output with no significant performance differences.

Applications and production

The Subaru EZ36 engine powered select premium models in Subaru's lineup, primarily targeting North American and select Asian markets. It debuted in the 2008 SUV, continuing through the 2014 model year, including the refreshed version from 2011 to 2014 that featured updated styling and minor interior enhancements. The engine was also fitted to the 2010–2019 Subaru Legacy and Outback in their 3.6R trims, serving as the upscale powerplant for these mid-size sedans and wagons. As Subaru's largest-displacement production engine, the EZ36 occupied a top-tier position in the brand's portfolio, delivering V6-equivalent performance combined with the inherent balance and low center of gravity of a boxer layout, which enhanced towing capacity up to 3,000 pounds and smooth highway cruising. The EZ36D variant, used across Tribeca, Outback, and Legacy applications, produced 256 horsepower (191 kW; 260 PS), with minor efficiency improvements in later production. Production occurred at Subaru's Gunma Oizumi Plant in Japan from 2007 to 2019, aligning with the vehicle's model cycles. The EZ36's production ended with the 2019 model year as Subaru transitioned to turbocharged four-cylinder engines, such as the 2.4-liter FA24F, to meet evolving fuel economy demands and market preferences for more efficient powertrains. In the aftermarket, the engine is prized for its overall durability, often exceeding 180,000 miles with proper maintenance, though high-mileage examples may experience occasional oil consumption related to aging seals and .

References

  1. https://www.autospeed.com/cms/a_2894/article
  2. https://www.carfolio.com/subaru-xt-6-18942
  3. https://www.edmunds.com/subaru/svx/1992/features-specs/
  4. https://www.motorreviewer.com/engine.php?engine_id=55
  5. https://carbuzz.com/what-the-last-subaru-flat-six-engine-model-costs-today/
  6. https://www.automobile-catalog.com/car/1989/3218495/subaru_xt6.html
  7. https://www.motorreviewer.com/engine.php?engine_id=54
  8. http://mywikimotors.com/subaru-ez36/
  9. https://japanesenostalgiccar.com/boxing-day-50-years-of-the-subaru-boxer-engine/
  10. https://japanesenostalgiccar.com/consider-the-following-subaru-xt/
  11. https://www.hagerty.co.uk/articles/subaru-svx/
  12. https://www.possumbournemotorsport.com/ez30-info
  13. https://www.torquenews.com/1084/say-goodbye-subaru-outback-36r-why-customers-won-t-miss-it
  14. https://www.subaruofcherryhill.com/subaru-boxer-engine-design.htm
  15. https://www.sportsubaru.com/subaru-boxer-engine.htm
  16. https://reman-engine.com/size/3.3-liter-subaru
  17. https://www.diyauto.com/engines/3-3l-eg33-f6
  18. https://www.npboosted.com/products/ignition-coils-for-subaru-outback-3-0-3-6-h6-b9-tribeca-legacy-ez30d-ez30r-ez36d
  19. https://legacypic.uk/engine/search.php?code=er27
  20. https://www.ultimatesubaru.org/forum/topic/163805-er27-turbo/
  21. http://xtremeracingtuning.com/Information/H6DO/EG33%20Engine.pdf
  22. https://www.auto-data.net/en/subaru-svx-cx-3.3-24v-230hp-16203
  23. https://www.subaru-svx.net/forum/showthread.php?t=11024
  24. http://mywikimotors.com/subaru-ez30/
  25. https://www.auto-data.net/en/subaru-legacy-iv-station-wagon-3.0r-245hp-awd-automatic-16171
  26. https://www.automobile-catalog.com/car/2006/3263105/subaru_legacy_3_0_r.html
  27. https://www.caranddriver.com/reviews/a15139518/subaru-outback-h6-30-vdc-road-test/
  28. https://www.automobile-catalog.com/car/2000/3251405/subaru_legacy_outback_h6_3_0.html
  29. https://en.avtotachki.com/dvigateli-subaru-ez36-i-ez36d/
  30. https://www.automaniac.org/engine/subaru/1551/subaru-3630cc-petrol-3.6-ez36-24v-260hp
Add your contribution
Related Hubs
User Avatar
No comments yet.