Method of Accelerated Evaluation of Automotive Engine Durability

The paper deals with the method of probabilistic car engine durability prediction. The method is based on observation of mechanical wear of elements composing piston-rings-cylinder assembly during short-term research and allows to calculate the probability of reaching wear limit value for a given time moment or mileage. The way of assessing the prediction error is also suggested. Two examples of calculation are made on the basis of cylinder liner wear data obtained from test-stand and truck on-road operational engine research. The prediction was verified in long-term maintenance studies carried out on five medium size trucks.

Proposed method of assessing engine durability does not require complicated computations. It can be easily used for results of wear measurements done in various conditions and with different methods. The condition of efficient application of the method is knowledge of reliable value of boundary wear and usage of run-in engines during the experiments. The method can be particularly useful for controlling effects of changes introduced during modernization of piston-rings-cylinder assembly on the engine durability.