The 4.3-liter Vortec Chevy V6 was the first Vortec engine ever made in 1986 and was used in GMC and Chevy trucks. The engine boasted 155 horsepower when it first appeared. The engine is based on what General Motors calls Vortex technology. The technology produces a vortex or mini-tornado inside the combustion chamber. The idea was to blend fuel and air more efficiently in the chamber, producing more power. This engine is the mainstay of the Chevy line of light trucks and vans.
The Base Engine
Chevy gave its 4.3-liter V6 a numerical designation of “4300.” This engine was built as a 90-degree Vortec engine that displaces 4,300 cubic centimeters or 262.3 cubic inches. This engine was based on the 350-cubic inch 5.7-liter V8 small block Chevy engine. The LB4 V6 4300 engine was used only in passenger cars, and then, in 1991, the engine expanded into light trucks.