No ohv refers to having the camshaft further down in the engine, operating pushrods connected, usually through a rocker arrangement, to the valves. A OHC is just refers to the fact that the cam is above the valves and operated on them more directly. CVH engines are OHC, but operate a type of rocker setup to allow the 8 valves to both be run from the single cam, yet still allowing them to be angled significantly. This combined with ports designed to vortex the incoming mix allowed (supposedly) more effiecient combustion, hence compound valve hemispherical CVH. Ford used to run loads of side valve engines and ones with the valves actually upside down compared to modern designs, most manifacturers engines are getting more and more similar, little individuality