Power Sports and Electronic Fuel Injection Glossary
VALUE ANALYSIS (VA)
Valve Device that opens and closes the combustion chamber of an internal-combustion engine to admit the fuel-air mixture or exhaust the gases.
VALVE FLOAT
A high-rpm engine condition in which the valve lifters lose contact with the cam lobes because the valve springs are not strong enough to overcome the momentum of the various valve train components. The onset of valve float prevents higher-rpm operation. Extended periods of valve float will damage the valve train.
VALVE LIFTER
Also called a "valve follower", the cylindrically shaped component that presses against the lobe of a camshaft and moves up and down as the cam lobe rotates. Most valve lifters have an oil-lubricated hardened face that slides on the cam lobe. So-called "roller lifters", however, have a small roller in contact with the cam lobe, thereby reducing the friction between the cam lobe and the lifter.
VALVES
Signifies the total intake and exhaust valves in an engine. For example, a 24-valve V-6 would have 4 valves per cylinder 24/6=4. A 16-valve V-8 would have 2 valves per cylinder 16/8=2. More valves allow the engine to breathe better at high RPM and produce more power.
VALVE TRAIN
The collection of parts that make the valves operate. The valve train includes the camshaft(s) and all related drive components, the various parts that convert the camshaft's rotary motion into reciprocating motion at the valves, and the valves and their associated parts.
VAPOR LOCK
Vapor lock occurs when an engine gets so hot, it boils the fuel traveling through the fuel lines. This creates vapor, which then prevents the engine from running.
VEE ENGINE
An engine with cylinders arranged in two rows at an angle to the common crankshaft. Has a 'V' shape when viewed from the front.
VEHICLE IDENTIFICATION NUMBER
The Vehicle Identification Number (VIN) is assigned to a vehicle by the manufacturer primarily for registration and identification purposes (consisting of numerals and letters).
V-ROD
The Harley-Davidson VRSCA V-Rod is a liquid-cooled, 1130cc V-Twin cruiser. The engine was designed by Porsche.
V-TWIN
A V-Twin is an engine having two cylinders placed at an angle to each other in the shape of a V.
