I’ve been working on valve adjustment, and with some modest 
success. In a gasoline engine, the valves let the air and fuel mixture from the carburetors into the cylinders for combustion and then the burned fuel out and into the exhaust pipe. If they don’t open and close completely, the engine will lack compression and not run well.
In the first picture, the tops of each of the eight valves can be seen on the top of the engine. The carburetors are on the side of the engine, each with a large hole for air;
the thin gasoline hose connects to a white “T” fitting between them. The exhaust pipe is barely visible under the engine.
“Adjusting the valves” is in theory simple but not so easy in practice. For the theory, one needs to slide a thin metal gauge between the top of each valve and what is the rocker arm. To the right, you can see the feeler gauge marked “012” near the top of the picture. The idea is to slide it under the rocker and adjust the screw barely visible at the 
bottom of the picture until the feeler gauge just slides in between the parts. The correct measurement ensures that the valves open and close fully.
From the practical point of view, there are eight valves, each of which needs to be adjusted when the engine is hot. This means that one needs to run the engine to operating temperature, remove the valve cover, and then make the adjustments. For this, one needs to turn the crankshaft until each valve is fully closed. I used a large socket and ratchet to turn the crank, but others use the starter or push the car while in gear. I found the socket method more precise.
The success? The compression in cylinder #2, which had been low, has increased to the acceptable range.
Sunbeam 