This causes excessive amounts of sludge to build up inside the engine ... and adequate engine vacuum. The valve consists of two chambers separated by a piston and a spring. The crankcase pressure ...

PVC air cannons are great, and everyone should build one of these at some point in their life, but what really makes this build exceptional is the valve. [Ben] created a piston valve for this ...

Interference engines allow the piston to go further into the combustion chamber to increase compression, and the valves to go deeper so they open wider and for longer. Both pistons and valves ...