Here is how I have always thought it worked.
The term L head refers to the valve configuration and the shape of the combustion chamber in relation to the cylinder bore. L head, I think, refers the the shape of the chamber with the intake and exhaust on the same side... valves both on one side of the cylinder. Hence the vertical arm of the letter L is the cylinder bore and the lower arm of the letter is the shape of the chamber.
Flat head: ie old Ford V8s, early Chrysler 6 cylinders, Model A and T Ford 4 cylinders and many others, were L heads too.
A hemi V8 has a half ball shaped chamber, usually (early Chrylser) one central cam and very long exhaust rockers to activate the exhaust valves. A double overhead cam engine has the same chamber and valve relationship with no rockers but almost direct contact between the cam lobe and the valve stems. One cam for intake and one for exhaust.(Many European and Japanese engines)
An F head (I think early Jeep engines had these) had an overhead valve (intake I beleive) and an in block exhaust valve.
Please don't think I am presuming to be an expert.... this is just the way I understood it over many years and I could be very wrong.
Comments?
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