Evo's are not unreliable at all, I have NEVER had one that we have tuned die or even break down at all for that matter, not even a reported missfire in 8 years of tuning them. When modded right they are pretty bomb proof, which is of course one of the main reasons they they are so popular.

Normally the standard components are pushed past their already high limit, or they are replaced with sub-standard components. Not the cars fault in either scenario, just bad tuning in 99% of cases.

Yours ma well just be a case of bad luck, all marques have Cases of bad luck, but i feel its unlikely since you suggest the bottom ends been replaced, and its a part of the bottom end that just broke.