Yeap, i agree, but this engine as 2 central injectors, and not 4!!!!

BUT, on the intake gasket / head to intake there is a coolant conduit, this
one is very close to the #4.... so that is my best guess.... as this
cylinder show heavy wear and groove, black spot and it was very dry....
Anyway, it's the first time i see that, and on top, this was a Honda
engine......with 220k miles one it.

Also, we flooded the engine on first start, so an hydro lock is possible, or
both, a tired cylinder/rod + the hydro lock....

Cheers, Ben
ps.: is the head missing for real!!!!!!!!!!! (he he he)