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Oversquare is bore greater than stroke.
Undersquare is bore less than stroke.
Volvo B 18,20,21,23, 230's are all oversquare.
Free revving (whatever that term is in the technology of internal combustion piston engines) relates to breathing and the ability to overcome internal friction and inertia. Compared to many engines from Japan, Volvo's don't breathe particulary well, and they certainly have a great deal of internal friction. The B230 was an attempt, and a bad one, to produce an engine with less internal friction. Unlike Japanese designs, Volvo traded longevity for lower friction. When a lowly 1.5 litre Honda engine can achieve 450,000 kilometers without having the cylinder removed, it is difficult to claim that Volvo has a lock on longevity. The B230 slap pistons, and the early ones take out their crankshaft thrust washers (last seen on an MGB) so badly that the flywheels or thrust plate contact the back of the block.
Torque is a function of cylinder filling efficiency, and that makes cylinder pressure. Torque is not the ability to lug, or respond smoothly to further application of throttle. That is flexibility, for lack of a better term, and not torque.
The Ford 300 six was a great engine, but it didn't make a lot of torque or horsepower. What it did have was flexibility, and the ability to lug down to low RPM, which was a function of a very archaic intake manifold, among other factors.
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