Originally Posted by augy
How low were they? Were these flat head engines basically an upside-down over-head valve engine, with the oil on top? Sorry, the logistics of this are a bit foreign to me
Bored as I am, I made a picture.
Note how huge the combustion chamber had to be. They where generally low compression engines because of this, plus the flow from the side mounted valves sucked. The engine is oiled normally, by crankcase spash and oil galleys.
Then along came overhead valve engines, and cars became significantly faster.