The first stroke of a cycle is the intake. The piston moves down to BDC, making space in the cylinder for fuel and air to be sucked or injected in through a valve. The compression stroke comes next.

starts with the piston at the top of the cylinder (TDC) and the intake valve open to admit air and fuel. At bottom-dead-center (BDC) the inlet valve is closed and the compression stroke (b) starts.

replacing the swivel handle with a homebrew pneumatic cylinder made in the shop. With a single button press, a swoosh of compressed air either clamps or releases the table. Best of all ...