Ventilverk

Ventilverk, in Swedish terminology, refers to the valve mechanism of an internal combustion engine that controls the opening and closing of the intake and exhaust valves. Its primary function is to regulate the flow of air and fuel into the combustion chamber and the exhaust gases out after combustion. The timing and duration of valve opening are crucial for engine efficiency, power, and emissions.

The valve mechanism can be arranged in several layouts. A traditional pushrod or OHV (overhead valve) design places the camshaft in the engine block and uses pushrods and rocker arms to actuate the valves. In overhead camshaft (OHC) designs, camshafts are located in the cylinder head, providing direct or near-direct actuation of the valves, often with fewer moving parts. Modern engines frequently employ variable valve timing (VVT) to adjust the timing and lift of the valves for different operating conditions. The timing of valve opening is synchronized with the crankshaft by a timing belt, chain, or gear train.

Key components include the camshaft(s), cam lobes, lifters or tappets, pushrods, rocker arms, valve springs, retainers, and the intake and exhaust valves themselves. The camshaft’s lobes translate rotary motion into the linear motion that opens valves, while springs close them when the cam lobe no longer holds them open.

Maintenance considerations involve ensuring proper lubrication, correct valve clearance, and reliable timing. Worn cam lobes, stretched timing belts, or misadjusted clearances can lead to reduced performance, increased emissions, or valve damage, especially in interference engines where valves can contact pistons if timing fails.