TorqueList Original Technical Art
Subaru EA52
Boxer4 · N/A
Subaru · EA Boxer
Subaru EA52
The 1.0-liter water-cooled boxer-four that launched Subaru's signature engine layout in the 1966 Subaru 1000.
59.5
Cubic inches
The EA52 was the first Subaru production boxer engine, establishing the low, compact layout that became central to the brand's identity.
Displacement
59.5 ci
Bore
2.835"
Stroke
2.362"
Years
1966–1969 core era
Key Takeaway
The EA52 established Subaru’s production boxer-four formula with an aluminum horizontally opposed block, OHV valvetrain, and compact 977 cc displacement. Its low, flat layout reduced engine height and helped define the packaging philosophy Subaru would continue for decades.
Technical Specifications
- Horsepower
- Varies by year/application; see documented variants
- Torque
- 7.8 kg·m @ 3200 rpm in 1966 Subaru 1000 factory specification
- Architecture
- Horizontally opposed boxer four
- Block
- Aluminum
- Cylinder heads
- Aluminum
- Valvetrain
- OHV, 2 valves per cylinder
- Aspiration
- Naturally aspirated
- Fuel delivery
- Carbureted
The EA52 established Subaru’s production boxer-four formula with an aluminum horizontally opposed block, OHV valvetrain, and compact 977 cc displacement. Its low, flat layout reduced engine height and helped define the packaging philosophy Subaru would continue for decades.
Internal Specifications
Variant-specific values are labeled. Engine families that span multiple years or RPOs can have different heads, cams, induction and rotating parts, so the exact code/year always takes priority.
Notable Applications
Strengths
- Low center of gravity
- Compact length
- Historically important Subaru architecture
Weaknesses / Watch-outs
- Very limited modern parts support
- Low output by modern standards
- Specialist restoration knowledge required
Common Upgrades
- Period-correct carburetor tuning
- Ignition modernization
- Cooling-system restoration
Racing History & Legacy
The EA52 is the beginning of Subaru’s long production-boxer lineage and the architecture that set the direction for every major Subaru engine family that followed.
References & Image Credit
Engineering Notes Worth Knowing
977 cc / 59.5 cu in horizontally opposed four-cylinder.
Aluminum block and heads with OHV two-valve-per-cylinder architecture.
Naturally aspirated and carbureted.
Introduced in the Subaru 1000, the first Subaru production model built around the boxer layout.
History · context · related reading
The Story Behind Subaru EA52
Subaru’s modern engine identity starts with the EA52. The small engine itself was modest, but its flat-four layout created the low center of gravity and compact longitudinal packaging that became a brand trademark.
TorqueList Garage Reference Series
See this engine inside the full Subaru reference catalog.
The same Engine Library data now powers a more detailed mobile-friendly catalog with technical specs, variants, engineering notes, history and related stories.