In many small engines, splash lubrication is used unlike in cars which always have an oil pump.
I understand that when the small engine is a vertical crankshaft one like in lawnmowers, where the cylinder is horizontal, the valve mechanism is actually at the same height as the oil pan is. So it's easy to have enough oil provided by gravity at the valve mechanism.
However, many small engines actually have a horizontal crankshaft like the engines in cars. In car engines, the valve mechanism is lubricated by oil pump feeding oil to the head via oil passageways. However, this mechanism is not possible in engines that don't have an oil pump.
So, how do small engines with a horizontal crankshaft manage to lubricate the valve mechanism?