Chevrolet Straight-6 engine
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| Straight 6 | |
|---|---|
| Manufacturer | General Motors Corporation |
| Type: | straight-6 |
| Production: | 1929 - 1990 |
| Successor: | GM Atlas engine |
The Chevrolet inline 6 of the 1930s through 1970s was the base engine in many popular cars, including the Chevrolet Camaro.
Contents |
[edit] 1929 Stovebolt Era
| First Generation | |
|---|---|
| Type: | inline-6 |
| Production: | 1929 - 1936 |
| Bore: | 3.3125 in (84.1 mm) |
| Stroke: | 3.75 in (95.3 mm) |
| Displacement: | 194 CID (3.2 L) |
| Power output: | 50 hp (37 kW) |
The first mass-produced GM inline-6 was introduced in 1929 on Chevrolet cars and trucks, replacing the company's inline-4. It was produced through 1936.
[edit] 194
It was 194 in³ (3.2 L) in size and produced 50 hp (37 kW). This engine used a forged steel crankshaft with three bearings and cast iron pistons. Bore and stroke was 3.3125 in (84.14 mm) by 3.75 in (95.25 mm). The 194 was shared with Chevrolet and GMC trucks for 1935 and 1936.
A balanced crankshaft was introduced for 1932, while a higher (5.2:1) compression ratio upped output to 60 hp (45 kW). A new cylinder head two years later pushed output to 80 hp (60 kW).
[edit] 181
A 181 in³ (3.0 L) version was used by Chevrolet and GMC trucks in 1935 and 1936.
[edit] 207
A 207 in³ (3.4 L) variant was used by Chevrolet and GMC trucks in 1934, 1935 and 1936.
[edit] 1937
The next-generation Chevrolet inline 6 was introduced in 1937 and phased out in 1953. Both were also shared with Chevrolet's trucks.
[edit] 216
This engine displaced 216 in³ (3.6 L) with a 3.5 in (88.9 mm) bore and the a 3.75 in (95.25 mm) stroke. A four-bearing crankshaft was added, along with 6.5:1 compression pistons, for 85 hp (63 kW). A new cylinder head in 1941 bumped output to 90 hp (67 kW), and 6.6:1 compression gave the 1949 model 92 hp (69 kW). This generation did not use a fully pressurized oiling system.The connecting rods were oiled using an "oil trough" built into the oil pan that had spray noozles that squirted a stream of oil that the connecting rods (which were equipped with dippers) caught on the fly and supplied the necessary oil for the rod bearings
[edit] 235
In 1941, a 235 cubic inch version of the 216 engine was introduced for use in large trucks. This engine also had a "dipper system" as described above, in reference to the oiling system, as in the 216.
The 235 in³ (3.9 L) version was added to cars in 1950 to complement the new Powerglide automatic transmission. Hydraulic lifters were used in the Powerglide 235 and a fully pressurized lubrication system was introduced in 1953, but only in cars ordered with the "Powerglide" transmissiion. Two versions were used in 1953 cars - a solid-lifter version with 123 hp (92 kW) for standard transmissions and the hydraulic-lifter 136 hp (101 kW) version for Powerglide use.
From 1954 to 1962, the high-pressure 235 cubic inch engine with mechanical valve lifters was used in trucks. From 1956-1962, all 235 cubic inch engines used in cars had hydraulic lifters.
It is interesting to note that the original 1953 Corvette engine was the high-pressure 235 cubic inch engine equipped with mechanical lifters. A 150 hp 235 engine was used in the 1954 Corvette and into 1955 (until they were all sold). The Corvette 235 was equipped with the same high-lift camshaft as used in the 261 truck engine.
[edit] 261
In 1954, a 261 truck engine was introduced as an optional Jobmaster engine for heavy-duty trucks. This engine was very similar to the 235 engine, except for a larger piston bore, two extra coolant holes (in the block and head) between three paired (siamesed) cylinders, and a higher-lift camshaft. The 261 USA truck engine had mechanical lifters and was available from 1954-62. In 1963, the 261 truck engines was available in 4x4 Chevrolet trucks (until the engines sold out).
The 235 and 261 truck engines were also used by GMC Truck of Canada (GMC truck 6-cylinder engines were also used in Canada). The 1955-1962 Canadian full-size Pontiac car had an optional 261 cubic inch engine that had hydraulic lifters. This engine was not sold in the USA but was very similar to the USA truck 261.
[edit] Generation 3
Chevrolet's third-generation inline-6 was introduced in 1962 (two years after rival Chrysler introduced its Slant Six) and produced through 1988. This generation was lighter in mass although the dimension were similar to the previous generation Stovebolts - the difference between the Stovebolt and the third generation sixes is the cast-in Chevrolet V8 bell housing pattern (similar to Chevrolet small block, big blocks, and the W-series). With the addition of the bellhousing redesign - transmission bellhousings (for manual transmissions) and automatics between Chevrolet V8s and sixes are interchangeable - this also includes the starter motors between both engines.
Although still considered a truck motor, the first usage was in the newly-introduced 1962 Chevy II; the following year, Chevrolet passenger cars (alongside Checker Marathons since 1965) used this powerplant until 1978 (1979 for Camaros and Novas). Chevrolet/GMC trucks, which previously used the Stovebolts (235 and 261), also used some members of this family from 1963 through 1984, as did Pontiac in 1964 and 1965. There was also a inline-4 version of this engine.
By the mid-1970s, the compact V-design (e.g. Buick 231) led to the phaseout of inline sixes in passenger cars where the inline six continued for usage in trucks and vans until 1988. It is common to find a Buick 3.8 and/or Chevrolet 4.3 in a mid-1980s GM RWD passenger cars with an elongated fan shroud since the motor's positioning is farther back than the inline six.
Overseas, the third-generation of the inline six was mass produced in Brazil. It was used at the Chevrolet Opala from 1969 (230) to 1992 (250). It was already used in light trucks as the A and Chevrolet Veraneio (this also includes the Brazilian version of the GMT400 - the Brazilian Chevrolet Silverado is powered with a 4.1 instead of the Vortec 4300). It was already converted for marine usage by Volvo Penta (the 4 cylinder version, the 151 was converted too), at stationary applications (power generation) and at Clark Forklifts.
[edit] 153
The 153 in³ (2.5 L) 153 was a straight-4 version of the family and was only used by Chevrolet. This engine is entirely different from the later 151 in³ Iron Duke, but the two are often confused today. That name was never used for this engine when it was produced.
Applications:
- 1962-1969 Chevy II
- 1967-1971 Postal Jeep
[edit] 194
The 194 in³ (3.2 L) 194 was shared between Chevrolet and GMC trucks.
Applications:
- 1962-1967 Chevy II
- 1964-1967 Chevrolet Chevelle
- 1965-1966 Studebaker Commander, Daytona ('66 only), Cruiser and Wagonaire (built by McKinnon Industries in Canada)
[edit] 215
Pontiac's 215 (1964-1965) is documented elsewhere.
[edit] 230
The 230 displaced 230 cubic inches (3.8L). It was also used by Chevrolet and GMC trucks. It produced 140 hp (100 kW). This engine was used on the following vehicles:
- 1964 Chevrolet Chevelle
- 1965-1968 Checker Marathon
- 1965 Chevrolet El Camino
- 1966-1970 Chevrolet Nova
- 1966 Studebaker Commander, Wagonaire, Daytona and Cruiser
- 1967 Chevrolet Chevelle
- 1967 Chevrolet Camaro
- 1969 Chevrolet Camaro
- 1969 Chevrolet Chevelle
[edit] 3.8
The Pontiac 3.8 was a special SOHC version of the standard 230 (3.8L) I6. An optional W53 version on the Firebird produced 215 hp (160 kW).
This engine was used on the following vehicles:
- 1967 Pontiac Firebird
- 1967 Pontiac Tempest Sprint coupe
[edit] 250
The stroked 250 version produced 145 hp (108 kW) for Chevrolet and GMC. Between 1975 - 1984, an integrated cylinder head was produced, with one-barrel intakes for passenger cars, and two-barrel intakes for trucks after 1978.
During the mid-1970s, the Buick 231 and Chevrolet V6-90 (basically a variant of the Chevrolet small block V8) was replacing the Chevrolet 250 for use in passenger cars and light duty trucks/vans. Passenger car use of the 250 (4.1L) was discontinued after the 1979 model year since the six was restricted to light truck usage (the 4.1 was discontinued after 1984 where the 4.3 V6 became the base motor). It would be GM's final inline six (along with the Chevrolet 292) until the introduction of the GM Atlas engine in late 2001.
This engine was used on the following vehicles:
- 1966-1984 Chevrolet (passenger cars to 1979, trucks/vans to 1984)
- 1968-1976 Pontiac Firebird
- 1968-1979 Chevrolet Camaro
- 1969-1979 Checker Marathon
- 1968-1992 Chevrolet Opala (Brasil)
[edit] L22
The L22 was a 250 in³ (4.1 L) I6 engine produced from 1967 to 1979. The 78' camaro had 105 horsepower (78 kW) and 190 ft·lbf (260 N·m) of torque with the 250.
[edit] LD4
The LD4 was a 250 in³ (4.1 L) I6 engine produced from 1978 to 1978.
[edit] LE3
The LE3 was a 250 in³ (4.1 L) I6 engine produced from 1979 to 1984.
[edit] 292
The 292 was only used in Chevrolet and GMC trucks; the block deck is taller, along with a relocated passenger-side engine mount. These were produced between 1963 to 1990; production of the engine shifted to Mexico after 1984.
[edit] L25
The L25 was GM's "last" straight-6 engine, produced from 1977 to 1985. It was used in Chevrolet trucks, displaced 292 in³ (4.8 L) and produced 115 hp (86 kW) and 215 ft·lbf (292 N·m).
[edit] Atlas
In 2002, GM announced a new family of straight-6 engines, the Atlas. Branded by GM under the Vortec name, the Vortec 4200 or Atlas LL8 is currently the only straight six available to the GM family of vehicles.
