This is a main big end for the Isuzu FVM and FTR model truck. A big end is the end of a connecting rod that engages with a crankshaft. The top end of the connecting rod is called the small end, and the bottom end is called the big end. He crawled under the engine every 15 miles or so to examine the big end for overheating.
A piston is a cylindrical engine component that slides back and forth in the cylinder bore by forces produced during the combustion process. The piston acts as a movable end of the combustion chamber. The stationary end of the combustion chamber is the cylinder head. Pistons are commonly made of a cast aluminum alloy for excellent and lightweight thermal conductivity.