Valve flutter
Valve flutter describes an uncontrolled operating condition of a four-stroke engine , which can lead to engine damage.
It can occur in four-stroke engines that are operated at an excessive speed . In normal operation, the movement of the valves is defined by the cam's elevation curve . The valve is opened in the rising part of the curve. The task of the valve springs is to push open valves back into their valve seats against inertia as soon as the camshaft allows this. With increasing speed, this movement has to be faster and faster, i. H. with ever greater accelerationrespectively. Above a certain speed, the valve springs are no longer able to generate the necessary force for such a movement. In extreme cases, the piston touches the valve that does not close in time and causes serious engine damage. Motors with desmodromic valve control are better equipped against valve flutter.
literature
- Richard van Basshuysen, Fred Schäfer: Handbook Internal Combustion Engine Basics, Components, Systems, Perspectives. 3rd edition, Friedrich Vieweg & Sohn Verlag / GWV Fachverlage GmbH, Wiesbaden, 2005, ISBN 3-528-23933-6