Damn, I take a step away from RHMT for a while...that eyeball had to really add injury to insult. :yes:
To add some tech.
Sleeve failure occurs due to excessive cylinder pressure.
Making mad powa is another reason.
Another way is valve failure. If for whatever reason your exhaust valve(s) fail to open, air will never leave your engine. It will cause the cylinder to over pressurize, and kaboom.
The last method I can think of is failure because of overheating(but pressure is still the killer). If your cylinders begin to overheat, the material becomes weaker.
Not so much excessive cyl pressure, but excessive average cylinder pressure. Exert X amount of pressure on iron for Y+1 period, and it will bypass plastic deformation to all-out failure. I'm guessing that's the B16 reasoning. The "ideal" r/s ratio puts a much higher average cyl pressure given the same MAX cyl pressure - it hangs near/at TDC for a longer period. There's also the possibity that the taller sleeves and sideload from the stroke deform b18 sleeves for just enough to let the highest pressure blow by the rings. I know it's all theory and practically impossible to prove, but it goes with the metalurgy I know.
Speaking of which, ferrous materials don't weaken much at those temps. The egt's may be 1500F, but due to many factors, they don't get nearly hot enough to weaken. Cast iron can take quite a lot, and won't change in structure unless 1500F is sustained. If nothing else, it's the fact the metal is work/heat hardened, the fabled visible OEM crosshatching becomes stress risers, and that high avg pressure pushes it over the tipping point.
ohhhhhhhrrrrrrr, b16's just use shity CDM sleeves.