V

The intake and exhaust valves in the head are 'poppet' type valves or (mushroom valves) with an operation as rising and falling valves consisting of a disk at the end of a vertically set stem, used in internal-combustion. ¹⁾

The distance a valve is lifted off it's seat by the camshaft lobe ²⁾

A precision instrument that measure both outside and non-cylindrical inside dimensions

Abbreviation for Vehicle Identification Number

A measure of thickness or resistance to flow of a liquid or flow-ability at definite temperatures and is one of motorcycle oils most important properties.

The viscosity index was developed by E. Dean and G. Davis in 1929. It is an empirically derived, unitless number. Based on the methodology, Pennsylvania crude (paraffinic) was set as a benchmark at one extreme, representing low viscosity changeability relative to temperature. At the other extreme was Texas Gulf crudes (naphthenic). If a lubricant was similar to the Pennsylvania crude, it was assigned a VI of 100. If it was similar to Texas Gulf crude, it was assigned a VI of 0. Halfway in between was a VI of 50, and so forth. The higher the VI, the more stable the viscosity across a range of temperatures (more desirable). The temperatures used to determine the VI are 40 degrees C to 100 degrees C. ³⁾

Kinematic viscosity is a measure of the resistive flow of a fluid under the influence of gravity. This measurement is generally displayed in most oil manufacturers respective TDS and/or SDS information data. When two fluids of equal volume are placed in identical capillary viscometers and allowed to flow under the influence of gravity, a viscous fluid takes longer than a less viscous fluid to flow through the tube. ⁴⁾ The most common unit of measure for kinematic viscosity is the square millimeter per second [mm2/s] or the centistokes [cSt]. One square meter per second is equal to one million centistokes. 1 mm2/s = 1 cSt ⁵⁾The standard evaluating temperature set for comparison is 40°C (104°F) and 100°C (212°F); example (Viscosity at 40°C ASTM D445 18.1 mm²/s)Therefore, viscosity cSt @ 40°C is 18.1 mm²/s.

(Saybolt Universal Seconds) are the number of seconds it takes for a fixed amount of hydraulic fluid to move through a standard-sized orifice at a fixed temperature. ⁶⁾

Vacuum Operated Electric Switch. Senses intake manifold vacuum from the carburetor and switches to one of two different spark advance curves. ⁷⁾

Research Voes: voes

Unit for expressing 'pressure' in a circuit. Volts= Current x Ohms ⁸⁾

Maintains voltage to the battery and load (lights, horn, ignition system etc.) at the same voltage regardless of engine speed or load. ⁹⁾

Return to Sportster Terminology Main Page