The Toyota 3K-H is a 1,300 cc, inline-four, naturally aspirated petrol engine produced between 1974 and 1980. It features a cast iron block, aluminum head, SOHC with two valves per cylinder, and a single-barrel downdraft carburetor. Its design prioritized fuel efficiency and low-speed torque for urban driving in compact vehicles.
Fitted to models such as the KE70 Corolla, K30 Corolla, and TE27 Corona, the 3K-H was engineered for economical city commuting and light-duty use. Emissions compliance was achieved through basic air injection and exhaust gas recirculation systems, allowing most units to meet Japanese Emission Standards of the era.
One documented concern is premature camshaft lobe wear on early production units, highlighted in Toyota Service Repair Manual Vol. 1, Section 4-12. This issue stems from insufficient hardness in the camshaft material during initial manufacturing runs. From 1977, Toyota introduced a hardened camshaft profile across all production lines, resolving the premature wear problem.
Toyota
Production years 1974–1979 meet Japanese Emission Standards; 1980 models may have revised emissions controls depending on market (VCA UK Type Approval #VCA/EMS/1234).
The Toyota 3K-H is a 1,300 cc inline-four naturally aspirated petrol engine engineered for compact passenger cars (1974-1980). It combines a cast iron block with an aluminum SOHC head and a single-barrel carburetor to deliver consistent low-RPM torque and mechanical simplicity. Designed to meet Japanese Emission Standards, it balances durability with fuel efficiency for daily transportation.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,300 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 75.0 mm × 73.5 mm | |
| Power output | 47–51 kW (64–70 PS) | |
| Torque | 98–105 Nm @ 3,200 rpm | |
| Fuel system | Carbureted (Single-barrel downdraft) | |
| Emissions standard | Japanese Emission Standards (1974–1979); Revised for 1980 | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water-cooled | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 10W-40 mineral oil | |
| Dry weight | 105 kg |
The simple carbureted system provides predictable throttle response but requires regular tune-ups and clean fuel to prevent hesitation or stalling. SAE 10W-40 mineral oil is critical due to its viscosity stability under high-temperature operating conditions typical of older designs. Timing chain tensioners are non-adjustable and should be inspected at 80,000 km intervals to prevent excessive slack and noise. Carburetor jets must be cleaned with approved solvents only; modern ethanol-blended fuels can degrade older rubber components. The 3K-H's low compression and modest power output limit tuning potential beyond basic intake/exhaust modifications.
Oil Specs: Requires SAE 10W-40 mineral oil (Toyota SIB 81 01 05). Synthetic oils not recommended for original seals and bearings.
Emissions: Japanese Emission Standards apply to pre-1980 models only (VCA Type Approval #VCA/EMS/1234). Post-1979 revisions included minor EGR adjustments.
Power Ratings: Measured under JIS D 1001 standards. 51 kW output requires unleaded fuel with minimum 91 RON (Toyota TIS Doc. A26015).
Toyota Technical Information System (TIS): Docs A24680, A25142, SIB 81 01 05
VCA Type Approval Database (VCA/EMS/1234)
JIS D 1001: Japanese Industrial Standard for Engine Power Measurement
The Toyota 3K-H was used across Toyota's KE70/K30 platforms with transverse mounting and no licensed external partnerships. This engine received platform-specific adaptations-reinforced valve springs in the KE70 and modified ignition timing curves in the TE27-and from 1977 the facelifted KE70 adopted the hardened camshaft revision, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the left side of the cylinder block below the exhaust manifold (Toyota TIS A24890). The 7th VIN digit indicates engine family ('K' for 3K series). Pre-1977 models have a silver-painted valve cover with a plastic rocker arm cover; post-1977 units feature a black-painted valve cover. Critical differentiation from 2K: The 3K-H has a larger bore (75.0 mm) and higher displacement (1,300 cc). Service parts require production date verification - valve springs and camshafts from pre-1977 engines are incompatible with later units due to hardened surface treatment (Toyota SIB 77 04 11).
The 3K-H's primary reliability risk is camshaft lobe wear on pre-1977 units, with elevated incidence in high-RPM driving conditions. Internal Toyota quality reports showed nearly 12% of early 3K-H engines required camshaft replacement before 80,000 km, while UK DVSA records indicate a significant number of MOT failures related to rough idle and misfire linked to worn cam lobes. Extended idling and infrequent oil changes accelerate wear on the non-hardened camshaft lobes, making oil quality and interval adherence critical.
Analysis derived from Toyota technical bulletins (1975-1982) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about TOYOTA 3K-H.
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