4-cylinder 8 valves OHV engine
OHV becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing OverHead Valve - an engine design where the camshaft is installed inside the engine block and valves are becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing through lifters, pushrods and rocker arms (an OHV engine also known as "Pushrod" engine). Although an OHV design is a bit outdated, it has been successfully used becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing decades. An OHV engine is very simple, has more compact size and proven to becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing durable. Downsides: it's difficult to precisely control the becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing at high rpm due to higher inertia caused by larger amount of valve train components (lifter-pushrod-rocker arm). Also it's very difficult to install more becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing 2 valves per cylinder or implement some latest technologies such as Variable Valve Timing - something that could be easily done in a DOHC engine.

4-cylinder 8 valves SOHC engine OHC or SOHC engine
OHC in general means becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing Cam while SOHC means Single OverHead Cam. In the SOHC engine the camshaft is installed in the cylinder becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing and valves are operated either by the rocker arms or directly through the lifters (as in the picture). The advantage is that valves are operated almost directly by the becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing - easy to achieve the perfect timing at high rpm. Also it's possible to install three or four valves per cylinder. The disadvantage - an OHC engine requires a timing belt or chain with related components - more complex and more becamshaftexpensiveforheadmeansoperatedOverHeadthanvalve timing design.