How important is draining hole in connecting rod? Do bearings always have holes?

[car5car]

I am installing aftermarket connecting rod bearings and they have holes. It looks like connecting rods have holes which are plugged from factory or clogged by old bearings falling apart. Oil is comming from crankshaft and draining from sides of bearings. What is connecting rod draining hole for? If holes clogged by pieces of old bearings what will hapen if I don't clean them? Dealer mechanics don't do short block jobs as far as I know. Thanks.

[JSM1284]

Those holes are what supplies oil to the bearings, They are neccessary to the engine. Without them the engine will failure very fast

[toyomoho]

The connecting rod should have a hole going from the upper bearing mount surface to the piston pin. Lubricate travels from the hole in the crank journal, through the hole in the bearing and up to the pin to provide lubrication. Make sure the hole in the rod is clear or the piston pin will seize in the rod.

The connecting rod cap normally does not have a hole in it. When installing the bearing make sure the hole in the bearing aligns with the hole in the top of the bearing mount. If no hole on the rod cap, just install the other half it will not harm the engine.