Valve device for a combustion engine

The apparatus has housings (10) that delimits a channel (16), and a valve body (20) rotatable arranged in the channel. A shaft (18) on which the valve body is secured, and is supported in the housing. The valve body extends a portion (22) to 90 degrees over a cross-section with a rotational axis in which a radius around the rotation axis is helically increased. A recess (52) is formed in the housing of another channel (12), in which the flap body (50) is completely arranged in a releasing position of the channel.