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The compression springs of the valves of automotive engines are key elements in the dynamic behavior of the engine. Its wear is slow, gradual and progressive; so the driver of the vehicle eventually get used to the decrease in the engine performance. The compressive force losses cause the valves to close slower than expected and, consequently, the engines lose their efficiency. Professionals in the area of automotive maintenance apply empirical tests with varying criteria to evaluate and to determine the life cycle end at which the springs must be replaced. This article describes the development of a workbench for compression springs based on existing models on the market and the main premise is the low cost. Correspondent loads involved were determined and the components were modeled in CAD, allowing to develop a robust device able to handle the loads generated by the compression spring.

Automotive shock absorbers are key elements in the dynamic behavior of vehicles. Their degradation is slow, gradual and progressive, so that the driver of the vehicle eventually gets used to the decrease of the damper's performance without noticing it. This article describes how a test bench was developed based on existing market models, however having as its main goal the low cost of production. The Crankshaft and Scotch Yoke mechanisms were studied in an analog way and simulated in CAD software. After this analysis the Scotch Yoke system was chosen because its motion describes a perfect sine function. To drive the system it was used a 5HP electric motor, and a frequency inverter to control the motor's speed with capability of 7.33A, allowing the device to have the ability to test not only production line vehicles but also competition dumpers.