out of steel, these rods connect the crankshaft to the pistons.
The connecting rod consists
of two parts: the main beam where a hole is machined for the wrist
pin. The beam also has a machined oil squirt hole on the upper cap
mounting face. A cap, that bolts to the main beam around the crankshaft.
Two-shell type bearings placed between the crankshaft and connecting
rod provide the proper oils clearance when the cap is torqued properly.
The bearings have passageways, which allow pressurized oil from the
crankshaft passages, to be forced out of the squirt
hole, up into the inside the cylinder area.
This oil lubricates the wrist pin, cylinder wall, and piston rings. The wrist pin is
pressed into place, through a hole in the side of the piston, holding the piston
in place. The pin is smaller than the hole in the piston.
So the piston can move freely.