Your local auto parts store can help you with that.
If the plastic caps are on the ports, the blue cap is on the lowside port that is the port to fill from. If the caps are missing the lowside port is the bigger of the 2.
No. The valves and ports are in the head. Unless it's a flathead. Not used much in automobiles after 1954.
Valves
The intake valves are in the intake ports, the exhaust valves are in the exhaust ports.
In the cylinder heads. The larger valves are the intakes. You'll notice that the passageway leads to the exhaust ports where the manifolds or headers attach.
As an air/fuel mixture is drawn into the intake ports, intake valves open to allow the mixture to enter the cylinder. On the exhaust stroke of an engine, the exhaust valves open, allowing the burned air/fuel mixture to exit out the exhaust ports. Intake valves are larger than exhaust valves, and are able to be found on the "cold" or intake side of the cylinder head(s).
A port and polich cleans all the build up off of the valves and ports it makes for better seating valves and the engine will run better
Open/close intake & exhaust ports. let in fuel. let out gases after combustion.
A piercing valve is a valve with a pointed sharp tip that is used to gain access to a sealed refrigeration system that does not have service valves or Schroeder ports. And is to be used as a temporary device .
valves are use in four stroke engine, and ports are use in two stroke engine.
There are two ports on the air conditioning compressor on the Mercury Mountaineer. The refrigerant to recharge the system is to be connected to the lower port.
pull it off and clean with some carb cleaner