General Motors Vortec engine
Vortec is a trademarked name for a line of gasoline engines for General Motors trucks. The name first appeared in an advertisement for the 1985 model year 4.3 L V6 that used "vortex technology" to create a vortex inside the combustion chamber, creating a better air / fuel atomization.
Source: Wikipedia — General Motors Vortec engine (CC BY-SA 4.0)