I am not sure what they are technically called, I think they are engine vents. What I am trying to find out is, on the left and right side [outside]of the Panzer IV J engine compartment are flaps or I believe vents. What are they if they are not what I am calling them? If they are vents, then are they always open?

They are inlet/outlet air vents for the cooling system. If you examine the seperate rear sections of the track guards on the Revell 1/72 kit you'll see two raised panels that are divided into four sections. These represent hinged flaps that can close off the vents if necessary. I think they would only be closed under extremely cold conditions.

they are air intake vents ole boy.

Thank you guys.
Hey ukgeoff,
Can you tell me if these vents were made of steel or sheet metal? I need to determine the thickness of sheet plastic to use on my 1/72nd Panzer IV J.

Wolf,
They are sheet metal covers for the engine compartment air intake. Close them up in cold weather to keep heat in the engine, open in hot weather to release heat. Made of light gage sheetmetal (not armor plate) In 1/72 scale, I would say use a heavy typing paper to fabricate them. The photoetch thickness in 1/35 scale is .005", so approx. half that for 1/72.
Just an idea......