OHC timing is a type of valve timing of a piston combustion engine, in which, in addition to the valves, the camshaft is also located in the cylinder head. The designation of this type of distribution is derived from the English name OverHead Camshaft.

Usually, only a rocker arm is inserted between the camshaft(s) and the valve. Thus, The OHC distribution contains a few components, which reduce inertial forces. The disadvantage of this type of distribution is only the more complicated construction of the cylinder head.

Valve timing is a mechanism using valves to control the flow of working gases (air, fuel, exhaust gases) through a piston combustion engine. This is the most common type of mechanical distribution, used mainly in four-stroke internal combustion engines.

The opening of the valves is controlled by the respective cam of the camshaft, which is driven by the crankshaft. In four-stroke engines, the camshaft rotates 2x slower than the crankshaft, because one working cycle of the engine takes two revolutions of the crankshaft.

Tire markings might confuse many people, as they cannot find their way around various numbers and letters on the tire. The markings convey important information about tires, such as size, specs, and what kind of safety standards were met.

This extensive guide will show you how to decode the markings on a specific example, so you won't get lost when you see the symbols on the rubber of a tire.