Chevrolet Small-Block engine
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| Missing image Hotrodmagchevy.jpg Cover of Hot Rod magazine Yearbook showing Chevrolet small-block engine | |
| Chevrolet Small-Block engine | |
|---|---|
| Manufacturer: | General Motors |
| Production: | 1955–1992 |
| Successor: | GM LT engine |
| Type: | small-block V8 |
| 265 | |
| Production: | 1954–1956 |
| Displacement: | 265 in³ (4.3 L) |
| Power: | 162–240 hp (121–179 kW) |
| Applications: | 1954–1956 Chevrolet Corvette 1955 Chevrolet Sedan |
| 283 | |
| Production: | 1957–1962 |
| Displacement: | 283 in³ (4.6 L) |
| Power: | 220–315 hp (164–235 kW) |
| Applications: | 1957–1962 Chevrolet Corvette |
| 327 | |
| Production: | 1962–1968 |
| Displacement: | 327 in³ (5.4 L) |
| Power: | 250–360 hp (186–268 kW) |
| Applications: | 1962–1968 Chevrolet Corvette |
| 302 | |
| Production: | 1967–1969 |
| Displacement: | 302 in³ (4.9 L) |
| Power: | 290 hp (216 kW) |
| Applications: | 1967–1969 Chevrolet Camaro Z28 |
| 400 | |
| Production: | 1970–1979 |
| Displacement: | 400 in³ (6.6 L) |
| Power: | 240 hp (179 kW) |
| 4.3 | |
| Production: | 1975–1976 |
| Displacement: | 262 in³ (4.3 L) |
| Power: | 110 hp (82 kW) |
| Applications: | 1975–1976 Chevrolet Monza |
| 5.0 | |
| Production: | 1976–1992 |
| Displacement: | 305 in³ (5.0 L) |
| Power: | 130–250 hp (97–186 kW) |
| Applications: | 1976–1979 Chevrolet Monza 1976–1979 Chevrolet Camaro |
| 350 | |
| Production: | 1969–1991 |
| Displacement: | 350 in³ (5.7 L) |
| Power: | 125–370 hp (93–276 kW) |
| Applications: | 1969–1991 Chevrolet Corvette 1975 Chevrolet Monza |
Chevrolet's small-block V8 is one of the most famous automobile engines in history. Originally called the "mouse motor" for its compact dimensions compared to other V8 engines of the time, production began in 1955 with the 265 in³ (4.3 L) engine used to bring performance credentials to the Corvette. The displacement changed over the years, eventually reaching 400 in³ (6.6 L), but none caught on like the 350 in³ (5.7 L) small-block. This engine would be produced through 1992, with more than 90,000,000 built.
Although Buick, Cadillac, Oldsmobile, and Pontiac also designed V8 engines (see list of GM engines), it was Chevrolet's 350 in³ small-block that became the GM corporate standard. Over the years, every American General Motors division except for Cadillac used the Chevrolet small-block, and its descendents (see GM LT engine and GM LS engine) continue as the company's mainstream V8 design today.
The Small-block was on the Ward's 10 Best Engines of the 20th Century list.
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Early Small Blocks
Most current GM small-block V8s (the LT and LS series) trace their lineage to the 1954 265 in³ V8 developed for the Corvette. Displacement and power eventually reached 377 in³ and 509 hp (in prototypes) before the Corvette switched to Chevrolet big-block power. But the small-block lived on, settling in at 350 in³ for decades of performance.
265
The 265 in³ (4.3 L) V8 was the first Chevrolet small block. Designed by Ed Cole's group at Chevrolet, it filled the power gap in the 1954 Corvette lineup, producing an impressive 195 hp (145 kW). The little engine went from drawings to production in just 15 weeks. Besides its compact dimensions, the small-block was known for its novel green-sand foundry construction process.
Dimensions were oversquare - 3.75 in (95 mm) bore and 3 in (76 mm) stroke. The small-block's 4.4 in (111.8 mm) bore spacing would continue in use for decades. It was a pushrod cast-iron engine with solid lifters and a 4-barrel Rochester carburetor. A passenger car version produced 162 hp.
The 1956 Corvette introduced three versions of this engine - 210 hp (157 kW), 225 hp (168 kW) with twin 4-barrel carbs, and 240 hp (179 kW) with a high-lift cam.
- 1954, 1956 Chevrolet Corvette
- 1955 Chevrolet, 165 hp (2-barrel) and 195 hp (4-barrel)
283
The 283 in³ (4.6 L) V8 was introduced in 1957. It was a version of the 265 in³ (4.3 L) bored-out to 3.87 in (98 mm). There were five different versions ranging from 220 hp to 283 hp (164 kW to 211 kW) depending on whether a single carb, twin carbs, or fuel injection was used. Power was up a bit each year for 1958, 1959, and 1960.
The 1957 engine featured Ramjet mechanical fuel injection, allowing the engine to produce 1 horsepower per cubic inch, an impressive feat at the time. For 1961, an amazing 315 hp was available from this unit.
- 1957-1962 Chevrolet Corvette
327
The 327 in³ (5.4 L) V8, introduced in 1962, was bored and stroked to 4 in (102 mm) by 3.25 in. Power ranged from 250 hp to 360 hp (186 kW to 268 kW) depending on the choice of carburetor or fuel injection. The L76 version produced 340 hp (254 kW) and 344 ft·lbf (466 N·m), while the L84 was the top performer with 360 hp (268 kW) and 352 ft·lbf (477 N·m) with solid lifers, a special cam, and Ram-Jet fuel injection. The 1966 L79 was the highest-performance that year 327 at 350 hp (261 kW) and 360 ft·lbf (477 N·m). 1967 saw two higher-performance versions - the 390 hp (291 kW) L36 and 435 hp (324 kW) L71.
- 1963-1968 Chevrolet Corvette
215
The Oldsmobile/Buick 215 V8 is documented under Buick V8 engine page.
302
Chevrolet produced a special 302 in³ (4.9 L) engine for Trans Am racing. It was the product of a 327 block and 283 crankshaft, and was only used in the first-generation Camaro Z28. Conservatively rated at 290 hp (216 kW), actual output was at least 320 hp (239 kW).
Later 302 in³ engines were produced for GM trucks and sold under the Vortec brand name. This block also formed the basis for the Vortec 4300 V6.
400
A 400 in³ small-block was introduced in 1970 and produced for 10 years. Initial output was 240 hp.
Later Small Blocks
This section documents the odd-size small blocks developed after the 350 appeared in 1969. Many of these basic blocks are variations of the 350 design.
4.3
The 4.3 was a 4.3 L (262 in³) 90° pushrod V8 with an iron block and heads. Bore and stroke were 3.67 in (93 mm) by 3.10 in (78.7 mm). Power output for 1975 was 110 hp (82 kW) and 195 ft·lbf (264 N·m).
This engine was used in the following cars:
- 1975-1976 Chevrolet Monza
5.0
The 5.0 variant of the 4.3 was bored and stroked to 5.0 L (305 in³) with a 3.74 in (95 mm) bore and 3.48 in (88.4 mm) stroke.
| Year | hp (kW) | ft·lbf (N·m) | |
|---|---|---|---|
| 1976 | 140 | 245 | 332 |
| 1977 | 140 | 245 | 332 |
| 1978 | 140 | 245 | 332 |
| 1979 | 130 | 245 | 332 |
This engine was used in the following cars:
- 1976-1979 Chevrolet Monza
- 1982-1992 Chevrolet Camaro
350
The first generation of Chevrolet small-blocks began with the 1955 Chevrolet 265 in³ (4.3 L) V8. But it was the 350 in³ (5.7L) series that set the standard for high performance. The engine's physical dimensions (oversquare 4.00 in bore and 3.48 in stroke, 102 mm by 88 mm) are nearly identical to the 400 hp (300 kW) LS2 engine of today, but of course much has changed.
This engine was used in the following cars:
- 1975 Chevrolet Monza - 125 hp (93 kW)
Note that Oldsmobile produced an entirely different 350 in³ V8 (4.057 in bore and 3.53 in stroke, 103 mm by 90 mm), the L34 and LF9 from the 1980s.
ZQ3
Years: 1969, 1970, 1972-1975
The ZQ3 was the standard engine in the 1969-1970 Chevrolet Corvette. It was a 300 hp (224 kW) version of the 350 in³ (5.7 L) small-block, with 10.25:1 compression and hydraulic lifters. It used a Rochester "4MV" Quadra-Jet 4-barrel carburetor.
The 1972 ZQ3 produced 200 hp (150 kW) and 300 ft·lbf (407 N·m) with 8.5:1 compression, dropping another 10 hp (7.5 kW) in 1973. 1975 saw the ZQ3 at 165 hp (123 kW) and 255 ft·lbf (346 N·m).
L46
Years: 1969, 1970, 1972
The L46 was an optional engine on the 1969-1970 Chevrolet Corvette. It was a 350 hp (261 kW), 380 ft·lbf (515 N·m) version of the ZQ3 with higher 11:1 compression. The 1972 ZQ3 produced just 200 hp (150 kW) and 300 ft·lbf (407 N·m) with an 8.5:1 compression ratio.
LT-1
Years: 1970-1972
The LT-1 was the ultimate 350 V8, becoming available in 1970. It used solid lifters, 11:1 compression, a high-performance camshaft, and a Holley four-barrel carburetor on a special aluminum intake to produce 370 hp (276 kW) and 380 ft·lbf (515 N·m). It was available on the Corvette and Camaro Z28. Power was down in 1971 to 330 hp (246 kW) and 360 ft·lbf (477 N·m) with 9:1 compression, and again in 1972 (the last year of the LT-1) to 255 hp (190 kW) and 280 ft·lbf (380 N·m).
Note that there was a later small-block engine called the "LT1".
More information (http://www.nastyz28.com/camaro/z28lt1.html)
L48
Years: 1971, 1976-1979
The L48 was the standard engine on the 1971 Chevrolet Corvette. It produced 270 hp (201 kW) and 360 ft·lbf (477 N·m) with an 8.5:1 compression ratio.
The 1976-1979 L48 was the standard Corvette engine and produced 180 hp (134 kW) and 270 ft·lbf (366 N·m). The 1980 L48 stood at 190 hp (142 kW) and 280 ft·lbf (380 N·m) from 8.2:1 compression.
L82
Years: 1973-1980
The 1973-1974 L82 was a performance version of the 350 producing 250 hp (186 kW) and 285 ft·lbf (386 N·m) from 9:1 compression. It was down to 205 hp (153 kW) and 255 ft·lbf (346 N·m) for 1975. It was the optional engine again in 1976-1977, producing 5 hp (4 kW) more. The 1978 L82 recovered somewhat, producing 220 hp (164 kW) and 260 ft·lbf (353 N·m), and 5 hp (4 kW) and 10 ft·lbf (14 N·m) more for 1979. 1980 saw another 10 hp (7.5 kW) and 15 ft·lbf (20 N·m).
More information (http://www.nastyz28.com/camaro/z28l82.html)
LG4
Years: 1982-1987
The LG4 was the "low output" 305 in³/ 5.0L (compared to the L69). It produced 145–170 hp (110–125 kW) and 240–250 ft·lbf (325–340 N·m).
L81
Years: 1981
The L81 was the only Corvette engine for 1981. It produced 190 hp (142 kW) and 280 ft·lbf (380 N·m) from 8.2:1 compression, exactly the same as the 1980 L48.
L83
Years: 1982, 1984
The 1982 L83 was again the only Corvette engine (and only available with an automatic transmission) producing 200 hp (150 kW) and 285 ft·lbf (386 N·m) from 9:1 compression. This was again the only engine on the new 1984 Vette, at 205 hp (153 kW) and 290 ft·lbf (393 N·m). The L83 added Cross-Fire fuel injection (twin throttle-body fuel injection).
L98
Years: 1985-1991
The new 1985 L98 added tuned-port fuel injection, which was good for 230 hp (172 kW) and 330 ft·lbf (447 N·m). It was standard on all 1985-1991 Corvettes. 1987 versions had 10 hp (7.5 kW) and 15 ft·lbf (20 N·m) more thanks to 9.5:1 compression. Compression was up again in 1991 to 10:1 but output stayed the same.
LM1
More information (http://www.nastyz28.com/camaro/z28lm1.html)
Generation II
See the GM LT engine page for more information on the newer small-block V8s.
Generation III/IV
See the GM LS engine page for more information on the newest small-block V8s.
See also
From the 1950s through the 1970s, each GM division had its own V8 engine family. Many were shared among other divisions, but each design is most-closely associated with its own division:
- Buick V8 engine
- Cadillac V8 engine
- Chevrolet Big-Block engine
- Oldsmobile V8 engine
- Pontiac V8 engine
GM later standardized on the later generations of the Chevrolet design:
- GM LT engine - Generation II small-block
- GM LS engine - Generation III/IV small-block
- List of GM engines