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Video Engine Technology
Video Piston Engines
Video Combustion Engine 1
Video Combustion Engine 2
Video Combustion Engine 3
Video Combustion Engine 4
Video Combustion Engine 5
Video Combustion Engine 6
Video Combustion Engine 7
Video Combustion Engine 8
Video Combustion Engine 9

Video Four-stroke Engine
Video Intake Stroke
Video Compression Stroke
Video Combustion Stroke
Video Exhaust Stroke
Video Save energy
Video Compl. dismanteled
Video Aggregate states
Video p-V Diagram 1
Video p-V Diagram 2
Video Fish Hook Curve Diagram
Video Decel. Fuel Shut-off
Video Equaliser Shafts 1
Video Equaliser Shafts 2
Video Inertial forces + -torques
Video Int. Combustion Engine
Video Petrol Engine
Video Diesel Engine
Video Alternative Engines
Video Classic 5-cyl. Engine
Video Classic V8-Engine
Video 6-cyl. Opposed Engine
Video 6-cyl. Opposed Turbo
Video V8 Turbo Engine
Video W12 Engine
Video V8 Ferrari Engine
Video V12 Ferrari Engine
Video Formula-1 Engine (image)
Video Formula-1 Engine
Video Engine Suspension
Video Perf. Measurement 1
Video Perf. Measurement 2
Video Torque Model
Video Torque 1
Video Torque 2

Video Torque 3
Video Stroke-bore Ratio
Video Cubic Capacity
Video Power output p.l.

Video Combustion Engine 1
Video Combustion Engine 2
Video Combustion Engine 3
Video Combustion Engine 4

Video Piston Engine 1
Video Piston Engine 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

  Intake Stroke

TemperatureApprox. 100C
Pressure0,8 - 0,9 bar (naturally aspirated engine)
Up to approx. 2 bar (charged standard engine)
Up to approx. 5 bar (charged racing engine)

The piston travels from TDC to BDC. The gases flow in through vacuum.
TDC = top-dead-center, BDC = bottom-dead-center

The animated working process.


During the intake-stroke of the four-stroke engine, the cylinder should be as completely filled as is possible, in all operational areas, with fresh gas. Specific used gas proportions can then be introduced (internal exhaust gas recirculation) by the engine management in certain, exactly defined operational areas.


The air- fuel -mixture with indirect injection, or pure air with direct injection, is sucked in by the (relatively low) pressure difference between the inlet manifold and the cylinder. This is caused by the movement of the piston, whereby the combustion chamber volume is increased. 09/11

Reasons for the opening before TDC and the closing after BDC
The gas-column is relatively inert.
It reaches it's highest speed about one third before BDC.
Used gases help to suck in fresh gas.
Cam operated stroke-valves open and close relatively slowly.

The angle from Io to Ec is called valve overlap.
The anlgle Ic is particularly important for the performance development.
Io/Eo = Intake/Exhaust opens, Ic/Ec = Intake/Exhaust closes               Top of page               Index
2001-2015 Copyright programs, texts, animations, pictures: H. Huppertz - E-Mail
Translator: Don Leslie - Email:

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