• The name Vortec can be used for a variety of GM's V8 engines.red truck engine image by Christopher Nolan from Fotolia.com
  
  For the model year 1997, GM unveiled a new LS1 Vortec engine, but only used it in the C5 Corvette that year. GMC and Chevrolet trucks and vans continued to use versions of a 5.7 Liter V8 small-block that was originally created in 1976. This was the Generation II LT1 engine, and it has the same specs with different configurations for various half-ton, light 3/4-ton models, regular 3/4-ton, and one-ton models.
  
  

Size and Power

• The 1997 LT1 Vortec engine is 5.7L, or specifically 5,733 cubic centimeters. This 190-kilowatt engine produces 255 horsepower at 4,600 RPM, or 250 horsepower for the larger Heavy Duty trims. Its torque is rated at 330 foot-pounds at 2,800 RPM.
  
  

Mechanics

• These Generation II LT1 engines feature nodular iron crankshafts, hypereutectic (as opposed to forged) pistons, and powdered metal connecting rods. There is a one-piece rear seal, and regular trucks and vans have two bolt mains while the 3500 and Heavy Duty models have four bolt mains. All are built without a mechanical fuel pump provision.
  
  The Vortec cylinder heads are 64 cubic centimeters, with an intake of 1.94 inches and a 1.5 inch exhaust.
  
  

Intake and Exhaust

• The 1997 Vortec engines feature roller camshafts with intake lift of 0.414 inches and exhaust lift of 0.428 inches. The intake duration at 0.05 inches is 191 while the exhaust duration is 196 at 0.05 inches. The lobe centerline, or degrees of separation between intake and exhaust, is 111 degrees.