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Video Engine Management

Video Cylinder Head 1
Video Cylinder Head 2
Video Cylinder Head 3
Video Cylinder Head 4
Video Cylinder Head 5
Video Cylinder Head 6
Video Cylinder Head 7
Video Cylinder Head 8
Video Cylinder Head 9
Video Cylinder Head 10
Video Cylinder Head Repair
Video Cylinder Head Gasket

Video Exchange of Gases
Video Comb. Chamber Shape
Video Cam
Video Camshaft
Video Adjustable Camshaft 1
Video Adjustable Camshaft 2
Video Adjustable Camshaft 3
Video Cambelt
Video Cambelt (assembly)
Video Camshaft Timing Chain
Video Camshaft Timing Chain
Video Upright Shaft
Video Timing Diagram
Video Valves
Video Valve drive
Video Natrium Cooled Valve
Video Valve Spring
Video Valve Stem Guide
Video Valve Seat
Video Valve Seat Angle
Video Valve Stem Sealing
Video Valve Overlap
Video Valve Play Adjustment
Video Valve Contr. (desmo.)
Video Hydraulic Lifter
Video Operating Valves
Video Var. Valve Timing 1
Video Var. Valve Timing 2
Video Var. Valve Lift 1
Video Var. Valve Lift 2
Video Drawrod Engine

Video Engine Control 1
Video Engine Control 2

          A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Side ValvesCamshaft lying below in the block,
2 valves in the side of the block
(valve-disc upwards)
Over Head ValvesCamshaft lying below in the block, 2 - 5 valves in the cylinder head(valve-disc downwards)
Over Head CamshaftOverhead cam(s)
lying in the cylinder head
Single Over Head CamshaftSingle cam lying
in the cylinder head
Double Over Head CamshaftTwin-cam lying
in the cylinder head

Overhead valveValve in the cylinder head, valve-disc nearer to the piston than the valve shaft
Side valveValve in the side of the cylinder block, valve-disc upwards, valve shaft downwards


The camshaft should open the valves at the right time, lifting them an exact amount and in a precisely determined sequence and make it possible for them to be closed again through the valve spring. The modern camshaft is driven by the crankshaft through gearwheels, timing belt or timing chain. In all cases, there is a transmission ratio of 2 : 1. Thus, the camshaft rotates only half as fast as the crankshaft.

Engine control: through shape and adjustment of the cams


A distinction is made between overhead- and side valves. In the case of the OVH-control, the camshaft is installed in the bottom of the engine block. The valves however, do their job in the cylinder head and are thus called overhead valves. The camshaft causes the valves to move through pushrods and cam followers. Because when the valves close and more components have to be moved back by the valve spring, higher RPM is not possible, side-valve engines are nowadays, only found the large volume (USA) V8-motor car-engines and in truck-engines. One, or two lie horizontally in the cylinder head and are driven through rocker-arms, cam followers or directly through tappets. The timing can, through either a mechanical- or a hydraulic adjustment be changed according to the engine speed.

The camshafts are made from cast iron, nodular cast iron, tempered steel or nitrided steel. They can be either cast or hollow-bored to save weight. Their bearings and the cam-paths are mostly surface-hardened. Camshafts can also be assembled from individual parts. Thereby, the cams and the bearings are pressed into their exact position through very high (water) pressure and then fixed. In contrast to the one-piece components, the cams can then be made from sintered material. The advantages are, lower production costs and weight-saving. 01/12               Top of page               Index
2001-2015 Copyright programs, texts, animations, pictures: H. Huppertz - E-Mail
Translator: Don Leslie - Email:

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