The spring tester is one of the most prolific pieces of test equipment that Jasper Engines uses. Located in every gas and diesel production pod, these machines ensure that valve springs meet O.E. specifications before assembly. Using air pressure it compacts the spring, and makes sure that the spring produces the correct amount of force at the right height, just as it should in your engine #jetbehindthescenes | Jasper Engines & Transmissions | Facebook