Complex sentence: The big end connects to the bearing journal on the crank throw, in most engines running on replaceable bearing shells accessible via the "connecting rod bolts" which hold the bearing "cap" onto the big end.
Split into simpler sentences: The big end connects to the bearing journal on the crank throw. In most engines, it runs on replaceable bearing shells that accessible via the "connecting rod bolts" that hold the bearing "cap" onto the big end.