[henk4]

Originally Posted by fpv_gtho

I rather DOHC for its better breathing and ability to rev

This has been a point of discussion all the time when the corvette C6 was being set off against european cars. Protagonists of the C6 invariably claim that pushrods are the best solution, only when you needed revs (and smaller engines) SOHC and DOHC would be a plausible solution. Of course in the US you don't need revs, as there is no replacement for cubic inches. European car tax systems have in some countries been based on displacement (a classic example of the consequences thereof is the existence of the Ferrari 208 turbo, which was the small displacement version of the 308 destined for the Italian market), resulting in optimising smaller sized engines.

So if you don't need revs you would go for pushrods. Fine, but there have been some developments in engine construction have largely escaped the avarage american (and australian) car nut. During the last ten years diesel engine developments have taken off like a space shuttle, and see what happens, these low revving engines (maximum 5000 but never necessary to go over 3500 or maximum 4000) are all fitted with one or two OHC's and 4 valves are now common as well. Why should that be? Is it because it always allows for a much better combustion process because you can place the valves in almost any position you wish? Coould well be, but for me it puts an end to the myth that pushrods are the way to go if you don't need revs.