Timing belt replacement can be easier since there are fewer camshaft drive sprockets that need to be aligned during the replacement procedure.
SOHC designs offer reduced complexity compared with overhead valve designs when used for multivalve cylinder heads, in which each cylinder has more than two valves.
The higher engine speeds thus allowed increases power output for a given torque output.
Disadvantages of the OHC design include the complexity of the camshaft drive, the need to re-time the drive system each time the cylinder head is removed, and the accessibility of tappet adjustment if necessary.
Though the system that drives the camshafts may be more complex, most engine manufacturers accept that added complexity as a trade-off for better engine performance and greater design flexibility.
The fundamental reason for the OHC valvetrain is that it offers an increase in the engine's ability to exchange induction and exhaust gases.
The multivalve Sprint version of the Triumph Slant-4 engine used a system where the camshaft was placed directly over the inlet valves, with the same cams that opened the intake valves also directly opening the exhaust valves via rocker arms.
Honda later used a similar valvetrain system in their motorcycles, using the term "Unicam" for the concept.
The OHC design allows for higher engine speeds than comparable cam-in-block designs, as a result of having lower valvetrain mass.
More than two overhead camshafts are not known to have been tried in a production engine.