Chevrolet Small-Block engine
Manufacturer:
General Motors
Production:
1955– 1992
Successor:
GM LT engine
Type:
small-block V8
265
Production:
1954– 1956
Displacement:
265 inł (4.3 L)
Power:
162–240 hp (121–179 kW)
Applications:
1954–1956 Chevrolet Corvette
1955 Chevrolet Sedan
283
Production:
1957– 1962
Displacement:
283 inł (4.6 L)
Power:
220–315 hp (164–235 kW)
Applications:
1957–1962 Chevrolet Corvette
307
Production:
1968– 1973
Displacement:
307 inł (5.0 L)
Power:
115–200 hp (86–149 kW)
327
Production:
1962– 1968
Displacement:
327 inł (5.4 L)
Power:
250–360 hp (186–268 kW)
Applications:
1962–1968 Chevrolet Corvette
302
Production:
1967– 1969
Displacement:
302 inł (4.9 L)
Power:
290 hp (216 kW)
Applications:
1967–1969 Chevrolet Camaro Z28
400
Production:
1970– 1979
Displacement:
400 inł (6.6 L)
Power:
240 hp (179 kW)
4.3
Production:
1975– 1976
Displacement:
262 inł (4.3 L)
Power:
110 hp (82 kW)
Applications:
1975–1976 Chevrolet Monza
5.0
Production:
1976– 1992
Displacement:
305 inł (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 inł (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 inł (4.3 L) engine used to bring performance credentials to the Corvette. The displacement changed over the years, eventually reaching 400 inł (6.6 L), but none caught on like the 350 inł (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 inł 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.
Early Small Blocks
Most current GM small-block V8s (the LT and LS series) trace their lineage to the 1955 265 inł V8 developed for the Corvette. Displacement and power eventually reached 377 inł and 509 hp (in prototypes) before the Corvette switched to Chevrolet big-block power. But the small-block lived on, settling in at 350 inł for decades of performance.
265
The 265 inł (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 1955 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 inł (4.6 L) V8 was introduced in 1957. It was a version of the 265 inł (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
307
A 307 inł (5.0 L) 307 version was produced from 1968 through 1973. Engine bore was 3.875 in (98.4 mm).
The 307 replaced the 283 in Chevrolet cars and produced 200 hp (149 kW) SAE gross in the 1960s. The later emmissions-modified versions produced just 115 hp (86 kW) SAE net, giving the engine one of the lowest power-per-displacement ratings of all time.
327
The 327 inł (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 375 hp (186 kW to 280 kW) depending on the choice of carburetor or fuel injection. The L76 version produced 340 hp (254 kW) and 344 ftˇlbf (466 Nˇm), while the L84 was the top performer with 360 hp (268 kW) and 352 ftˇlbf (477 Nˇm) 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 ftˇlbf (477 Nˇm). 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 inł (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 inł 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 inł 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 inł) 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 ftˇlbf (264 Nˇm).
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 inł) with a 3.74 in (95 mm) bore and 3.48 in (88.4 mm) stroke.
The first generation of Chevrolet small-blocks began with the 1955 Chevrolet 265 inł (4.3 L) V8. But it was the 350 inł (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 inł 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 inł (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 ftˇlbf (407 Nˇm) 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 ftˇlbf (346 Nˇm).
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 ftˇlbf (515 Nˇm) version of the ZQ3 with higher 11:1 compression. The 1972 ZQ3 produced just 200 hp (150 kW) and 300 ftˇlbf (407 Nˇm) 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 ftˇlbf (515 Nˇm). It was available on the Corvette and Camaro Z28. Power was down in 1971 to 330 hp (246 kW) and 360 ftˇlbf (477 Nˇm) with 9:1 compression, and again in 1972 (the last year of the LT-1) to 255 hp (190 kW) and 280 ftˇlbf (380 Nˇm).
Note that there was a later small-block engine called the "LT1".
More information
L48
Years: 1971, 1976-1979
The L48 was the standard engine on the 1971 Chevrolet Corvette. It produced 270 hp (201 kW) and 360 ftˇlbf (477 Nˇm) with an 8.5:1 compression ratio.
The 1976-1979 L48 was the standard Corvette engine and produced 180 hp (134 kW) and 270 ftˇlbf (366 Nˇm). The 1980 L48 stood at 190 hp (142 kW) and 280 ftˇlbf (380 Nˇm) 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 ftˇlbf (386 Nˇm) from 9:1 compression. It was down to 205 hp (153 kW) and 255 ftˇlbf (346 Nˇm) 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 ftˇlbf (353 Nˇm), and 5 hp (4 kW) and 10 ftˇlbf (14 Nˇm) more for 1979. 1980 saw another 10 hp (7.5 kW) and 15 ftˇlbf (20 Nˇm).
More information
LG4
Years: 1982-1987
The LG4 was the "low output" 305 inł/ 5.0L (compared to the L69). It produced 145–170 hp (110–125 kW) and 240–250 ftˇlbf (325–340 Nˇm).
L81
Years: 1981
The L81 was the only Corvette engine for 1981. It produced 190 hp (142 kW) and 280 ftˇlbf (380 Nˇm) 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 ftˇlbf (386 Nˇm) from 9:1 compression. This was again the only engine on the new 1984 Vette, at 205 hp (153 kW) and 290 ftˇlbf (393 Nˇm). 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 ftˇlbf (447 Nˇm). It was standard on all 1985-1991 Corvettes. 1987 versions had 10 hp (7.5 kW) and 15 ftˇlbf (20 Nˇm) more thanks to 9.5:1 compression. Compression was up again in 1991 to 10:1 but output stayed the same.
LM1
More information
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:
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