Hubbry Logo
Toyota Type A engineToyota Type A engineMain
Open search
Toyota Type A engine
Community hub
Toyota Type A engine
logo
7 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Toyota Type A engine
Toyota Type A engine
from Wikipedia

The Type A engine was a straight-six engine produced from 1935 through 1947 by Toyota and is a copy of the 1933 Chevrolet Stovebolt 207 engine.[1]

The Type B was a technically more advanced version of the Type A. There was an enlarged version of this, called the Type D, but it did not enter production.

The Type C was a straight-four engine derived from the Type A.

Many parts were interchangeable between the Type A, Type B and Type C engines (e.g. pistons, valves, rods). Many of the same parts were also interchangeable with the 1930s Chevrolet First generation Stovebolt engines, from which it was derived.

The Type E was a copy of a DKW engine.

The Type S was a straight-four engine that replaced the Type A, B and C in Toyota's passenger cars.

Type A

[edit]
Type A
Overview
ManufacturerToyota
Production1935–1947
Layout
ConfigurationI6
Displacement3,389 cc (3.4 L; 206.8 cu in)
Cylinder bore84.1 mm (3.3 in)
Piston stroke101.6 mm (4.0 in)
Cylinder block materialiron
Cylinder head materialiron
ValvetrainOHV
Combustion
Fuel systemcarburettor
Fuel typeGasoline
Output
Power output62 PS (46 kW; 61 hp)

The Type A engine was Toyota's first production engine, being produced from 1935 through 1947.

This engine was a 3,389 cc (3.4 L; 206.8 cu in) pushrod, overhead valve, 6-cylinder, three bearing engine copied from the 1929–36 Chevrolet Gen-1 3 bearing Stovebolt L6 OHV engine. By virtue of a modified intake manifold it produced 62 PS (46 kW), while the Chevrolet engine produced 60 PS (44 kW). GM used a number of local Japanese suppliers for the smaller engine parts (e.g. carburettors) while the Osaka Assembly location was open until appropriated by the Imperial Japanese Government.[2] Toyota was able to use the same suppliers for its cars. The parts were identical enough that pistons, rods, valves, etc. could be used in both the Chevrolet and Toyota engines interchangeably. There are several recorded instances of parts intended for one being used to repair the other.[1]

Toyota had initially considered copying the Ford flathead V8 engine because it was the most popular engine in Japan at the time. However, the machining of two separate banks of cylinders would add too much to the production cost, so the Chevrolet engine was copied instead.[1] The Ford Model T was also being manufactured in Japan beginning in March 1925,[3] followed by the Ford Model A in 1927; both used the flathead Ford Model T engine.

Other references to the Chevy engine claim different power figures. Different manufactures used different measuring techniques (e.g. with or without the generator/alternator connected), engines differed from year to year, and some manufacturers simply lied. In this case, Toyota did back-to-back comparisons using the same techniques, so it is likely that the Toyota engine did in fact produce slightly more power than the Chevy engine on which it was based, which was likely to be a year or two old.

Applications

[edit]
  • A1 prototype car
  • AA sedan
  • AB cabriolet
  • G1 truck
  • GA truck

Type B

[edit]
Type B
Overview
ManufacturerToyota
Production1938-1956
Layout
ConfigurationI6
Displacement3,386 cc (3.4 L; 206.6 cu in)
Cylinder bore84.1 mm (3.3 in)[4]
Piston stroke101.6 mm (4.0 in)[4]
Cylinder block materialiron
Cylinder head materialiron
ValvetrainOHV
Compression ratio6.4:1[4]
Combustion
Fuel systemcarburettor
Fuel typeGasoline
Output
Power output75-85 HP
Chronology
SuccessorToyota F engine

The 3,386 cc (3.4 L; 206.6 cu in) Type B was a more technically advanced version of the Type A. Production commenced in November 1938 with the opening of Toyota's Koromo plant.[5] The design was based on the Chevrolet 207 engine, and built under license but with metric dimensions and minor revisions to suit the local market. It had a four-bearing crank and shaft-mounted rocker arms, as did the Chevrolet engine. The type B engine remained in production until 1956 at least.

The original output was 75 PS (55 kW) at 3000 rpm. In January 1940 this was increased to 78 PS (57 kW) at the same engine speed. Another bump, to 82 PS (60 kW) occurred at the time of the BM truck's introduction in March 1947.[5] A 1944 prototype for a large passenger car called "Toyota Large B" also received the B-series engine, although with a higher 6.9:1 compression ratio and producing 85 PS (63 kW).[6] This was also the output of the improved engine fitted to the 4-ton BA and 2.5-ton BC trucks which were built until February and July 1956 respectively.[7][8]

The Type B was complemented and eventually supplanted by the similar 3.9 L Type F which first appeared in 1951. The Type F is based on the larger OHV GMC Straight-6 engine built from 1939 until 1963 in the same way that the Type A and Type B were based on the Chevrolet engines of their times. There was also an experimental 4-liter version called the Type D.

An unrelated four-cylinder diesel engine introduced in the 1970s was also called the Type B.

Applications

[edit]
  • Toyota AC sedan
  • 1938-1942 Toyota GB truck
  • 1940-1941 Toyota HB truck, a shortened GB
  • 1942-1944 Toyota KB truck
  • 1943-1947 Toyota KC/KCY truck
  • 1944-1945 Shinyo (suicide motorboat)[9]
  • 1947-1951 Toyota BM truck, also shorter wheelbase BS model from 1949
  • 1949- Toyota BL bus
  • 1951-1955 BX/BZ truck (82 PS)[10]
  • 1951-1955 BJ Jeep (predecessor to the Land Cruiser)
  • 1952- Toyota BQ 3/4-ton 4WD truck, reserved for security and police forces
  • Toyota BH26 Police Patrol Car (using a modified Toyopet Crown RS body)
  • Toyota BH28 Ambulance
  • 1954-1956 BA/BC truck (85 PS, improved BX type)

Type C

[edit]
Type C
Overview
ManufacturerToyota
Production1939-1941
Layout
ConfigurationI4
Displacement2,259 cc (2.3 L; 137.9 cu in)
Cylinder bore84.1 mm (3.3 in)[11]
Piston stroke101.6 mm (4.0 in)
Cylinder block materialiron
Cylinder head materialiron
ValvetrainOHV
Compression ratio6.4:1
Combustion
Fuel systemcarburettor
Fuel typeGasoline
Output
Power output49 PS (36 kW; 48 hp)
Torque output152 N⋅m (112 lb⋅ft) @ 1400 rpm

The 2,259 cc (2.3 L; 137.9 cu in) Type C was produced from 1939 through 1941. It was formed by removing two cylinders from a Type A engine.

Applications

[edit]

Type D

[edit]
Type D
Overview
ManufacturerToyota
Production1944 (prototype)
Layout
ConfigurationI6
Displacement4,052 cc (4.1 L; 247.3 cu in)
Cylinder bore92.0 mm (3.6 in)[5]
Piston stroke101.6 mm (4.0 in)
Cylinder block materialiron
Cylinder head materialiron
ValvetrainOHV
Combustion
Fuel systemcarburettor
Fuel typeGasoline
Chronology
SuccessorToyota F engine

The 4,052 cc (4.1 L; 247.3 cu in) Type D was a larger version of the B engine developed in early 1944, featuring an increased bore while retaining the same stroke. It was a direct response to a national order issued in 1940, instructing Toyota to develop a higher output engine based on the B.[5] It did not enter series production, with Toyota instead developing the somewhat smaller Type F engine after the war. Output was 100 PS (74 kW).[5]

Type E

[edit]
Type E
Overview
ManufacturerToyota
Production1938
Layout
ConfigurationI2 two-stroke
Displacement585 cc (0.6 L; 35.7 cu in)[11]
Combustion
Fuel systemcarburettor
Fuel typeGasoline

The 585 cc (0.6 L; 35.7 cu in) Type E was produced in 1938 only for the prototype EA sedan. It was a copy of the two-stroke engine used in the DKW F7.

Applications

[edit]

Type S

[edit]
Type S
Overview
ManufacturerToyota
Production1947-1959
Layout
ConfigurationI4
Displacement995 cc (1.0 L; 60.7 cu in)
Cylinder bore65 mm (2.6 in)[11]
Piston stroke75 mm (3.0 in)
Cylinder block materialiron
Cylinder head materialiron
Valvetrainside valve
Compression ratio6.5:1
Combustion
Fuel systemcarburettor
Fuel typeGasoline
Output
Power output27 PS (20 kW; 27 hp)
Torque output98 N⋅m (72 lb⋅ft) @ 2400 rpm
Chronology
PredecessorNone
SuccessorToyota P engine

The 995 cc (1.0 L; 60.7 cu in) Type S was produced from 1947[12] through 1959. It was unrelated to previous Toyota overhead valve engines, being designed by reverse-engineering a 1930s Adler Trumpf Junior's engine, and used the less sophisticated flathead engine design which was short lived.[citation needed]

Applications

[edit]

See also

[edit]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia
from Grokipedia
The Toyota Type A engine was the first gasoline engine developed and produced by Toyota Motor Corporation, introduced in 1934 as a 3.4-liter inline-six-cylinder unit with overhead valves, designed primarily to power the company's inaugural passenger vehicles and trucks. It featured a cast-iron block and head, , and a displacement of 3,389 cc, delivering 65 horsepower at 3,000 rpm and 150 lb-ft of torque between 1,300 and 2,000 rpm. With a bore of 84.1 mm and stroke of 101.6 mm, the engine was a four-cycle, pushrod design that marked Toyota's entry into automotive manufacturing under the leadership of . Development of the Type A began in May 1934 at the Toyoda Automatic Loom Works' automotive division in Koromo, , inspired by the six-cylinder from a 1933 Chevrolet sedan to accelerate Toyota's transition from production to automobiles. The first prototype was completed on September 25, 1934, after overcoming challenges in casting the cylinder block and through innovative techniques, including the use of an oil core provided by engineer Risaburo Oshima. Initial output was modest at 48-49 hp, but redesigns to the cylinder boosted performance to the final 65 hp rating before production. The incorporated a mix of in-house manufactured components, such as the cylinder , block, and pistons, with imported parts like the and sourced from Chevrolet to expedite development. The Type A engine debuted in Toyota's first production vehicles, including the Model AA four-door sedan launched in April 1936 and Model AB phaeton in September 1936, as well as the Model GA truck launched in September 1936. Production of the AA totaled 1,404 units and the AB 353 units between 1936 and 1943, when wartime demands halted civilian vehicle manufacturing in Japan. Engine production continued sporadically until 1947, primarily for military applications, before being succeeded by the improved Type B engine in later wartime and postwar models, such as the 1943 Model AC. This engine laid the foundational engineering expertise for 's automotive expansion, influencing subsequent designs and symbolizing the company's shift to under the newly independent Toyota Motor Co., Ltd., established in 1937.

Historical Background

Origins and Influences

, son of inventor , founded the automotive division of Toyoda Automatic Loom Works in 1933, leveraging profits from the family's textile machinery business to finance vehicle development. In 1929, Sakichi had sold the patent rights to his innovative automatic loom to the British firm Platt Brothers for £100,000, directing these funds specifically to Kiichiro to pursue automotive ambitions and diversify beyond looms. This capital infusion enabled the establishment of the Automotive Production Division on September 1, 1933, marking Toyota's initial entry into car manufacturing within the existing loom company structure. The design of the Type A engine drew direct inspiration from the 1933 Chevrolet Stovebolt 207, with personally disassembling a Chevrolet passenger car in October 1933 to sketch its components and guide the engine's development. This reverse-engineering approach was facilitated by access to Chevrolet vehicles assembled at ' Osaka plant, which had begun operations in 1927 as part of GM's efforts to serve the Japanese market. By basing the Type A on this established American inline-six design, aimed to ensure reliability and manufacturability from the outset, adapting proven technology to local needs. In the 1930s, Japan's automotive sector operated amid government initiatives to foster domestic production and curb foreign dominance, as American firms like Ford and General Motors controlled much of the market through local assembly. The Automobile Manufacturing Industry Law, enacted in 1936, restricted foreign automakers' expansion—capping their output at existing levels—and mandated that new production occur domestically to build a self-sufficient industry. These policies, driven by military preparedness and foreign exchange conservation, encouraged companies like Toyoda to prioritize passenger cars and trucks as alternatives to prevalent imports from Ford and Chevrolet. This foundational emphasis on competing with imported models through localized engineering laid the groundwork for Toyota's shift toward prototyping the Type A engine and initial vehicle builds.

Prototyping and Early Production

The development of the Type A engine began in earnest in May 1934, when the Toyoda Automatic Loom Works' automotive division started prototyping cast parts such as cylinder blocks and pistons, drawing on sketches of the 1933 Chevrolet sedan engine as a reference. The team encountered significant engineering hurdles early on, particularly in forming the water jacket core for the cylinder block, which proved difficult to achieve with available methods; this was overcome in August 1934 through the use of an oil-based core developed by engineer Risaburo Oshima. Manufacturing capabilities were constrained, with in-house efforts limited to casting components like the cylinder head, block, and pistons, while precision elements such as crankshafts and camshafts were procured from external suppliers due to gaps in domestic tooling and expertise. These limitations highlighted broader challenges in adapting foreign designs to Japanese production realities, including frequent defective castings that accumulated in large piles and the need for manual processes like hand-hammering , reflecting tool shortages and skill deficiencies among the workforce. By September 25, 1934, the first Type A was completed after iterative trials, marking a pivotal milestone in Toyota's entry into . Building on this, the A1 prototype passenger car, incorporating the Type A engine, was assembled in May 1935 at the Kariya facility, serving as a for integrating the with a body inspired by the 1934 DeSoto sedan. Production of the AA sedan followed in 1936, with an assembly plant constructed near the Toyoda head office in May of that year to support initial output; a total of 1,404 units were built before wartime disruptions. To scale up, Toyota broke ground on the Koromo Plant in September 1937, which became operational in November 1938 as an integrated facility for , , and assembly, enabling output to ramp from dozens to hundreds of vehicles annually and solidifying the Type A engine's role in the company's nascent vehicle lineup.

Straight-Six Variants

Type A Engine

The Toyota Type A engine was a straight-six, overhead-valve (OHV) design with a displacement of 3,389 cc, serving as the foundational powerplant for Toyota's initial automotive ventures. It featured a bore of 84.1 mm and a stroke of 101.6 mm, along with a compression ratio of 6.4:1, and was constructed with a cast-iron block and head for durability in early production environments. The engine employed a three-bearing forged steel crankshaft, reflecting its direct adaptation from the 1933 Chevrolet Stovebolt 207 cubic-inch design with minimal modifications to suit local manufacturing. This configuration delivered 65 hp (48 kW) at 3,000 rpm under early gross power measurement standards, following redesigns that improved initial prototype output from 48-49 hp. Production of the Type A engine spanned from 1935 to 1947, beginning with prototypes completed in September 1934 and scaling to support Toyota's nascent vehicle lineup amid wartime constraints. It powered the A1 passenger car prototype in May 1935, marking Toyota's entry into automobile assembly. The engine's primary applications included the sedan, produced from 1936 to 1943 as the company's debut production passenger vehicle, and the AB phaeton variant, built from 1936 to 1938. Additionally, it equipped the G1 truck from 1935 to 1936 and the GA truck from 1936 to 1940, providing reliable propulsion for Toyota's initial commercial offerings with a focus on 1.5- to 2.5-ton payloads. A notable engineering aspect of the Type A was its water-cooled, four-cycle operation with a single , optimized for fuel and emphasizing simplicity for in . During wartime, adaptations included restricted civilian output and repurposing, though the core design remained unchanged until post-war evolutions. This engine's straightforward architecture, derived from proven American precedents, enabled Toyota to achieve an initial production target of 200 units per month by 1936, laying the groundwork for the company's automotive expansion.

Type B Engine

The Toyota Type B engine represented an evolution of the predecessor Type A, featuring a straight-six overhead valve (OHV) configuration with a displacement of 3,389 cc. It incorporated key mechanical upgrades, including a four-bearing crankshaft constructed from special cast steel, which enhanced reliability and durability compared to the three-bearing design of earlier models. The engine maintained a bore of 84.1 mm and stroke of 101.6 mm, with a compression ratio of 6.0:1 and wet-sump lubrication system. Power output varied by version, delivering 75 hp (56 kW) at 3,200 rpm in the standard configuration and up to 85 hp (63 kW) at 3,600 rpm in later high-compression variants, alongside torque of 22.0 kg-m (159 lb-ft) at 1,600 rpm for improved low-end performance. Production of the Type B engine spanned from 1938 to 1956, commencing with prototype development in late 1937 and full-scale manufacturing at the Koromo Plant starting in December 1938. Designed with metric dimensions, a full water , and a gear-type oil pump, it addressed limitations in the imperial-unit-based Type A while boosting output from 65 hp to an initial 75 hp. These enhancements positioned the engine for heavier-duty applications, emphasizing increased torque suited to hauling demands over passenger priorities. The Type B found primary use in Toyota's truck lineup and select sedans, powering the AC sedan from 1943 to 1947 as a civilian model. It drove the GB truck series (1939-1959), along with the KB truck (from 1942) and KC truck variants (from 1943), supporting both domestic logistics and export markets. Military adaptations included the BJ Jeep prototype (1951-1953), where the engine's robust torque enabled four-wheel-drive configurations for off-road testing by Japan's Police Reserve Force. Overall, its longevity in production underscored its role in Toyota's transition from wartime to manufacturing.

Type D Engine

The Type D engine was a straight-six, overhead-valve (OHV) prototype developed by Toyota Motor Co., Ltd. in early 1944 as part of wartime efforts to enhance engine capabilities. It served as an enlarged version of the Type B engine, with a displacement of 4,052 cc achieved through an increased bore, targeting an output of 100 hp (74 kW). Development of the Type D was spurred by Japan National Order No. 30, issued on September 13, 1940, which required Toyota to produce an engine delivering at least 85 PS by improving upon the existing Type B design for potential use in larger trucks or generators. The bore was specifically enlarged from 84.1 mm to 92 mm to boost power while maintaining the inline-six configuration and cast-iron construction common to Toyota's early engines. A single prototype was completed in 1944, incorporating advanced features such as a five-bearing that was progressive for the period. However, it underwent only limited testing amid escalating wartime constraints. The engine never advanced to production due to the end of in August 1945, acute material and resource shortages throughout the conflict, and Toyota's reorientation toward immediate military production demands that sidelined civilian and prototype projects.

Inline-Four Variants

Type C Engine

The Toyota Type C engine was a straight-four, overhead (OHV), water-cooled engine developed as a downsized derivative of the Type B engine by removing two cylinders, resulting in a displacement of 2,258 cc from a bore of 84.1 mm and stroke of 101.6 mm. It featured a of 6.4:1 and produced 50 hp (approximately 49 PS or 36 kW) at 2,800 rpm, prioritizing in line with a 1938 Ministry of Commerce and Industry request for engines under 2,400 cc to support resource conservation amid rising wartime demands. Prototype production of the Type C began in May 1937 and concluded in March 1939, with full production spanning 1939 to 1941 as Toyota shifted focus toward military output during escalating war preparations in . The engine's design incorporated many interchangeable components from the Type A and related Type B engines, such as pistons and other shared parts, to minimize costs and streamline manufacturing under material shortages. However, its production run was brief, limited by strict wartime restrictions on passenger vehicles and the redirection of resources to larger engines for trucks and military needs. Applications of the Type C were confined to experimental and utility vehicles, including the Model AE medium-sized passenger car prototypes completed in September 1939 and tested for over 1,500 km, with approximately 76 units produced by 1940. A variant, the BA model with a wooden body for steel conservation, added 17 units in May 1940, bringing total output to around 100 engines. It also powered early prototypes like the AK10 small four-wheel-drive truck in 1944, intended for light military transport but limited to experimental use due to the emphasis on heavier-duty engines. These wartime constraints curtailed broader adoption, marking the Type C as a short-lived efficiency-focused adaptation.

Type S Engine

The Type S engine represented Toyota's initial foray into economy-oriented powerplants following , serving as the company's first dedicated four-cylinder design for civilian recovery efforts. Developed amid severe material shortages and the need to replenish depleted inventories of pre-war engines like the Type A, B, and C, it prioritized simplicity, fuel efficiency, and low-cost manufacturing to support Japan's economic rebuilding. This straight-four, side-valve (SV) unit was reverse-engineered with reference to the German Adler Junior's compact layout, resulting in a water-cooled inline-four configuration with a cast-iron block for durability and ease of maintenance. It featured a displacement of 995 cc (bore × stroke: 65 × 75 mm), a of 6.5:1, and simple single-carburetor fuel delivery, delivering 27 PS (20 kW) at 4,000 rpm and 5.9 kg·m of at 2,400 rpm. Production of the Type S spanned from 1947 to 1959, with the prototype completed in November 1946 and initial units entering service the following year. Its robust construction, including the side-valve arrangement and basic carburetion system, facilitated straightforward repairs using readily available parts, aligning with the era's resource constraints. The engine's emphasis on efficiency—achieved through modest power output and optimized for low-speed operation—made it ideal for light-duty transport in a fuel-scarce environment, marking a shift from Toyota's earlier six-cylinder focus toward affordable, mass-producible components. Early applications centered on recovery vehicles, beginning with the sedan and SB truck introduced in 1947. Approximately 50 SA units were produced initially for government and military use, with total SA output reaching 215 vehicles through 1952, underscoring its limited civilian rollout amid production restrictions. The SB truck saw broader adoption, with 12,796 units built by February 1952, leveraging the engine's reliability for tasks. In the , the Type S powered the Toyopet SD (from November 1949) and (from June 1950) models, facilitating Toyota's gradual return to passenger car manufacturing and contributing to the Toyopet lineup's role in domestic mobility recovery. By its discontinuation in 1959, the engine had enabled over a decade of transitional vehicle production, bridging wartime austerity to modern automotive expansion.

Experimental Engines

Type E Engine

The Toyota Type E engine represented the company's sole venture into two-stroke engine design, serving as a straight-2 powerplant copied from the DKW F7 compact car engine studied at Toyota's Shibaura Laboratory in 1936. With a displacement of 584 cc achieved through a bore of 74 mm and a stroke of 68 mm, it was engineered for compactness and lightness to suit small passenger vehicles. The engine delivered 18 hp at 3,200 rpm, emphasizing efficiency in a low-displacement configuration. Development of the Type E began in June 1937 under the leadership of for the engine and Shiguma Ikenaga for the suspension, with prototype assembly at the Kariya Plant before transfer to the Koromo Plant. Intended as a lightweight power source for economical small cars, it remained strictly a effort, with only ten units completed by 1940, some featuring wooden bodies for testing. No series production followed, as wartime restrictions on passenger car manufacturing shifted priorities toward military vehicles and technology preservation for postwar recovery. The Type E found exclusive application in the EA sedan prototype, a front-engine, front-wheel-drive developed from 1938 to 1940 to explore affordable mobility options. This layout drew directly from the DKW's innovative front-wheel-drive architecture, positioning the transverse two-cylinder engine ahead of the driver to drive the front wheels via a three-speed . Despite its potential for simple, low-cost propulsion, the engine's two-stroke cycle was ultimately sidelined in favor of proven four-stroke designs for Toyota's production lineup. Key to its operation was the two-stroke cycle employing port-based scavenging, where intake and exhaust ports in the walls facilitated without valves, enabling a power stroke every revolution for higher specific output in a compact form. This brief pre-World War II experiment highlighted Toyota's early interest in European principles, though it marked the end of such pursuits amid escalating global conflict.

References

Add your contribution
Related Hubs
User Avatar
No comments yet.