plemetal.blogg.se - How a dual overhead cam works

Using two camshafts to actuate the rotation of the valves allows engine builders to control the intake and exhaust valves separately, instead of other arrangements with only one camshaft that lack that precision.īy taking control of the exhaust and intake valves independently, this arrangement offers engineers greater control over the fuel consumption of the engine and the exhaust flow created by combustion.

The energy created by combustion in the cylinders yields the power that turns the wheels and drives the car, as well as hot exhaust gasses that must escape the cylinders and flow out of the car.Īccordingly, engines have a series of valves that control the flow of the intake and exhaust. Motors have an engine block, housing the cylinders where internal combustion happens.Ī mix of fuel and air feeds that process, and combustion occurs when a spark ignites the mixtures. We have to talk about some engine basics to understand what that means. You first have to know that DOHC stands for Dual Overhead Camshaft. But what does it mean when you notice the DOHC emblem or insignia on a vehicle or when listed on the spec sheet for a particular engine?

DOHC Engine Advantages and DisadvantagesĬarmakers use combinations of letters to denote their unique models, advanced systems like Electronic Stability Control (ESC), and sometimes even the name of their company.

The camshaft rotates at half engine speed. Camshaft drive belt A toothed belt - often called the timing belt - drives the camshaft from a sprocket mounted on the end of the crankshaft. A pipe from the oil pump draws up the oil through a strainer. Sump The sump contains the lubricating oil for the engine's moving parts. Crankshaft The crankshaft transmits power to the road wheels through the gearbox. Connecting rod The connecting rod converts the up-and-down movement of the pistons into rotary motion through a treadle action. It helps to transmit the engine power and to smooth out the individual impulses of the pistons so that the power flows evenly. Flywheel The flywheel is a heavy disc attached to the end of the crankshaft. Piston The piston is fitted with steel rings which fill the gap between it and the cylinder wall.

The parts of an overhead-camshaft engine Camshaft The camshaft has pear-shaped lobes which actuate the valves - usually one inlet and one exhaust valve for each cylinder.