The LT-1 was the ultimate 350 cu in (5.7 L) 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 lbÃ‚Â·ft (515 NÃ‚Â·m). It was available on the Corvette and Camaro Z28. Power was down in 1971 to 330 hp (246 kW) and 360 lbÃ‚Â·ft (488 NÃ‚Â·m) with 9:1 compression, and again in 1972 (the last year of the LT-1) to 255 hp (190 kW) and 280 lbÃ‚Â·ft (380 NÃ‚Â·m).
There was also a later small-block engine called the "LT1".
GM LT1 from a 1993 Chevrolet Camaro Z28.
In 1992, GM created a new-generation small-block engine called the LT1, recalling the 1970 LT-1 moniker. It displaced 5.7 L (350 cu in) and was a 2-valve pushrod design. The LT1 used a reverse-flow cooling system which cooled the cylinder heads first, maintaining lower cylinder temperatures and allowing the engine to run at a higher compression than its immediate predecessors.
This engine was used in:
o 1992-1996 Chevrolet Corvette C4
o 1993-1997 Chevrolet Camaro Z28
o 1993-1997 Pontiac Firebird Formula and Trans Am
o 1994-1996 Buick Roadmaster
o 1994-1996 Chevrolet Caprice
o 1994-1996 Chevrolet Caprice Police Package
o 1994-1996 Chevrolet Impala SS
o 1994-1996 Chevrolet Caprice Wagon
o 1994-1996 Buick Roadmaster Wagon
o 1994-1996 Cadillac Fleetwood
There were a few different versions of the LT1. All feature a cast iron block, with aluminum heads in the Y and F bodies, and cast iron heads in the B and D bodies. Corvette blocks had four-bolt main caps, while most other blocks were two-bolt main caps.
The 92-93 LT1s used speed density fuel management, batch-fire fuel injection and a dedicated engine control module (ECM). In 94 the LT1 switched to a mass airflow sensor and sequential port injection. A new, more capable computer controlled the transmission as well as the engine and got a new name: powertrain control module (PCM). Where the ECM held its calibration information in a replaceable chip, the PCM was reprogrammable through the diagnostic port.
The early Opti-spark distributor had durability problems and a revised version was introduced on the 1994 B-Bodies and in 1995 on the Y and F-Bodies. 1996 saw major revisions for OBD-II - a second catalytic converter on the F-body cars and rear oxygen sensors to monitor catalyst efficiency. Some OBD-II features had been added to the Corvette starting in 1994 for testing purposes. The 1997 model year Camaro and Firebird were the last year for this engine in a GM production car.
The 1992 LT1 in the Y-body was factory rated at 300 hp (220 kW) and 330 lbÃ‚Â·ft (447 NÃ‚Â·m). 96 LT1 Y-bodies were rated at 300 hp (220 kW) and 340 lbÃ‚Â·ft (461 NÃ‚Â·m). The 93-95 F-bodies were rated at 275 horsepower (205 kW) and 325 lbÃ‚Â·ft (441 NÃ‚Â·m), while the 96-97 cars were rated at 285 horsepower (213 kW) and 335 lbÃ‚Â·ft (454 NÃ‚Â·m). The 96-97 WS6 and SS F-bodies were rated at 305 hp (227 kW). The 94-96 B and D-body version was rated at 260 horsepower (190 kW) and 330 lbÃ‚Â·ft (447 NÃ‚Â·m).