Which are the intake and which exhaust valves on a Mazda 6 RF7J diesel engine?

The intake valves are located on the top of the cylinder head, and the exhaust valves are located on the bottom. The intake valves are opened by the camshaft, and the exhaust valves are opened by the exhaust camshaft. The intake valves allow air and fuel to enter the cylinder, and the exhaust valves allow the exhaust gases to escape from the cylinder.