I've heard this arguement before and the conclusion was yes the length of the stoke does change the displacement. Not TOTAL displacement, but USABLE displacement. The XB9 and 12 share the same cylinder jugs, most engine manufaturers don't use the commonality of changing the stroke to create two engines. The longer stroke uses more of the bore to create 219cc more displacement than the 984. This expressed mathmatically as stroke, it's just a different way of expressing it.
So, the head work would need to consist of new valves and springs and having the head machined? Ported and polished. Any thing special?
Say you stuck an XB12 crank n rods in, retained the XB9 cylinders, and did the head work. Which would make more horses, The aforementioned engine or a bigbore kitted XB12? OR would the head work be virtually the the same and the real differnce would be in the big bore kit?
How much HP is an XB engine capable of making anyhow? 140?
Both will effect reliablity and engine life. WHat would would cryo-ing all the components do? Save expansion and contraction issues, I think they cryo the dry engine as a whole. Indy car and sports car racing teams cryo their race engines to make the metal harder and stronger. There are several places here in Indy that do this.
