DICTIONARY OF AUTOMOTIVE TERMS - "Hc"

HC

Acronym for unburned Hydrocarbons. They are at their worst with very rich or very lean mixtures. They combine with NOx in sunlight to form Photochemical Smog.

HCDS

Acronym for High Clutch Drum Speed

HC engine

A high-camshaft engine; the camshaft is located much higher than the crankshaft, (although not in the cylinder head), allowing for the use of shorter pushrods, thus improving the engine's revving ability.

HCFC

Acronym for Hydrochlorofluorocarbon. A gaseous compound that meet current environmental standards for minimizing stratospheric ozone depletion.

H/CMPR

Acronym for High Compression

HCV

1. Acronym for Heavy Commercial Vehicles.
2. Acronym for Exhaust heat control valve