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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

Exchange of Gases

The exchange of burnt mixture for fresh gases in the cylinder is also referred to as exchange of gases. With the two-stroke engine one speaks of scavenging.

Open exchange of gases

It develops when inlet and outlet ports are open at the same time for a certain period of time. Fresh gas could directly end up in the exhaust gas and vice versa. This problem is less dramatic for the four-stroke engines because the time frame is limited to the period of the valve overlap. Besides, the valve timing and channels are designed such that mixing of fresh gas and old gas does not take place. It is rather a problem for two-stroke engines, affecting negatively exhaust gas emissions and mileage.

Closed exchange of gases

Valves open and close the inlet and outlet ports in such a way that as little as possible fresh gas escapes into the outlet port and a good filling without old gases is ensured. The closed exchange of gases is typical for the four-stroke engine. However, there are also valve-controlled two-stroke engines. 06/08               Top of page               Index
2001-2015 Copyright programs, texts, animations, pictures: H. Huppertz - E-Mail
Translator: Don Leslie - Email:

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