| Loads acting on a con-rod are gas load from piston and inertia loads from all reciprocating parts. Inertia loads acts as a correction to gas loads. The thrust or end loading are push pull in nature( tensile+compressive) in 4s, and purely compressive in 2s. So con rods of 4s undertake more stresses so the must be made with i beam cross sections. failure occurs in 2s if started with oil or liquid in 2s in 4s failure may occur due to fatigue failure, bearing seizure also leads o buckling. |
Since very small needle lift is obtained in the test equipment result in an unequal pressure distribution in the cut off shaft resulting in a hard contact in a small area along with high frequency oscillations, low lubricity of test oil will increase the chance of seizure. Full lift and high lubricity of heavy oil eliminates this risk of seizure during normal operation.( Always open and clean slide type valves before testing as cold sticky heavy oil along with small clearances can cause restriction in the movement of the spindle).
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