Diesel Engine Connecting Rod Bearing Failure

The following are typical assembly errors most often made in the installation of engine bearings.

Diesel engine connecting rod bearing failure. Of all the things that can take your engine out bearing failure is one of the most insidious. The piston cooler if bent can cause a piston to seize and cause the piston pin bearing to fail. Excessive idling can result in an oil film that can not support the load needed. Also shown is a damaged piston cooler.

2 4 correct reversed position of offset connecting rod reversed bearing caps in wrong or. Sometimes a fairly new engine can have fatigued connecting rods if it is a rebuilt engine and the mechanic used cheap parts or the wrong parts for the engine. But bearing wear can have broad ranging. This paper presents the results of a failure analysis investigation conducted in a connecting rod from a diesel engine 18 v four stroke used in.

When a connecting rod or main bearing cap is installed in the wrong position. Engine bearings will not function properly if they are installed incorrectly. Failures in con rods have been reported in the literature being associated to fatigue overload bending bearing failure improperly adjusted bolts spalling and assembly deficiencies. Such a failure may or may not be the rod s fault.

The small end attaches to the gudgeon pin also called piston pin or wrist pin which can swivel in the piston. The above pictures show two areas of failure the connecting rod bearing and the cylinder kit. Typically the big end connects to the crankpin using a plain bearing to reduce friction. In many cases misassembly will result in premature failure of the bearing.

Catastrophic connecting rod failure can be as a result of incorrect clearances causing bearing failure incorrect torque applied to the fasteners engine over speeding resulting in hyper articulation of the connecting rods and connecting rod bolt failure. If a bearing isn t set into place securely lubrication will be insufficient and cause failure. Other causes of engine bearing failure. Either way the engine is going to need a new rod.

Careful installation procedures are of course critical in every aspect of engine building careless errors are always expensive. Pin failure the pin that connects the connecting rod to the piston called the piston pin wrist pin or gudgeon pin gets a lot of wear. A connecting rod for an internal combustion engine consists of the big end rod and small end. If the oil film between the rod bearing and crank journal goes away for any reason even for an instant it can overheat and seize the bearing.

Car oriented types tend to try to ignore bearing issues compensating for them by using ever thicker oil and an eye on the gauges instead of just replacing them as necessary. If a connecting rod or main bearing cap is installed in the wrong position or a bearing isn t set into place securely lubrication will be insufficient and cause failure.