Exhaust Manifold

The exhaust manifold on a Model A, or any internal combustion engine, moves the mixture of exploded fossil fuel and air (unexploded fuel, oxygen and carbon monoxide) away from the engine, through a long, curved tube called an exhaust pipe to the rear of the car. The main function of the exhaust pipe is to move the carbon monoxide away from the passenger compartment of the Model A so that the passengers do not get sick or die. I don't know about your Model A, but there is so much fresh air getting into the car from around the doors, through the trunk, through assorted holes in the firewall and floorboard, not to mention the windshield gasket leaks.

Since an internal combustion engine sucks in a mixture of gasoline and air, it is definitely a fire hazard. That is what we are counting on. The piston on the upward slope creates pressure by squeezing the gasoline and air (about 90 lbs/square inch if you have a high compression head) and then at just the right time the spark plug fires a small amount of flame and the mixture literally explodes, pushing the piston down and propels your car down the road.