Repair And Fix it

Rod bearings or connecting rods connect the pistons to the crankshaft and must be strong to withstand the internal forces from pistons directional changes as well as transmit the piston thrust to the crankshaft. Rod bearings are mainly made of aluminum for smaller engines and forged steel. The upper end of the rod bearing is connected by a piston pin to the piston and the lower end of the rod is split so that it is clamped around the crankshaft in a certain style.

I-Beam

I-beam are the most common styles of rod bearing connection and are used for performance builds and stock applications. These rods are characterized by a large flat area perpendicular to the side beams. The rod side beams are parallel to holes found in the crank journal and piston pins, providing an excellent combination of compressive and tensile strength as well as light weight. I-beam rods handle high rpm tension although they might bend or fail when exposed to high compressive forces. I-beams can be made wider or thicker so that they can handle large horsepower loads.

Oval Beams

Oval beams are also erred to as parabolic or radial beams and are a variation of the basic I-beam. They are created by leaving a rounded region next to the two beams, thus increasing the rigidity and strength. This scalloped effect created by the rounded area is aimed at improving the performance of rod bearings and minimizing bending or failure of rod bearings.

H-Beams

H-beam rods are made of two big flat-sided beams lying at a 90 degree angle to the crankshaft journal bores and the piston pin. Lateral stiffness is provided by the center region linking the two sides of the H jointly. In comparison with the I-beam, this design weighs less and has superior compressive power. H-beam style is recommended for applications with high torques generating huge amounts of power below 6,000 rpm.

Implications

Rod bearings are specifically engineered to meet particular requirements that take into consideration the amount of load produced by the engine. For example, passenger cars are not frequently full-loaded and might require different rod bearings from applications with heavier loads, such as marine or heavy duty trucks. Also take into consideration that putting more load on the bearing makes it difficult to maintain the oil film connecting the bearing and shaft, reducing the longevity of the rod bearings.