It is quite a chore to get the connecting rods out of some engines. On many small bore European engines, the big end of the connecting rod is too large to go through the cylinder sleeves which, when removed, will allow the rod to come through the block opening. In many engines the rod is split at an angle, to facilitate removal. Note that cap screws with locking plates, rather than studs or bolts, are used to hold the rod bearing cap in place with this type of construction.
An unusual situation is found in one English engine. The connecting rod will not come out through the cylinder bore, and the piston will not clear the crankshaft. The solution in this case, however, is to remove the connecting rod cap and push the piston up out of the bore on top. The floating piston pin is then removed to free the piston, and the rod is removed from below.
The opposed, or pancake, engine usually has a barrel crankcase split longitudinally, and it is necessary to dismantle the engine to get the robs out. Sometimes it may be possible, with the engine out of the car, to get one rod out by removal of the cylinder barrel on the opposite side.
Generally, on U.S. engines, the first step is ridge reaming to remove the unworn portion of the cylinder wall above piston ring travel. Then the rod caps are removed, and the entire piston and rod assembly is pushed up and out of the cylinder. Rods and their respective caps must be kept together and marked for cylinder location.