Originally posted by pepengtom
how come?
e ang DOHC = double overhead cam
SOHC = single overhead cam?
so why not its depending on the 4v/cyl not on the camshaft?
let me rephrase:

1. four valves per cylinder is always better than 2 valves per cylinder because the engine 'breathes' and burns gas more efficiently.

2. most 4 valve per cylinder engines are DOHC because it's easier to design them that way. SOHC engines tend to be 2 valves per cylinder. of course, there are exceptions to both.

3. therefore, people tend to think that DOHC is better than SOHC, when in reality DOHC engines tend to be the better engines because they have two more valves per cylinder - not necessarily because they have another camshaft.