Recently I've run into a series of problems with my car and one of them turned out to be weak valvesprings. I was able to get my hands on a spring tester that allowed me to test the closed pressure on some of my springs. I say some only because the size of the guage did not allow me to get to the springs under the cowl. I was able to access the first 5 springs on the drivers side pretty easily and found one to be reading pretty low when compared to the others (85 lbs to open) compared to the other 4 that required 130 lbs. Since my heads/cam package came from ARE I decided to give them a call to see what they recommended I replace the originals with. I was told K-Motion 750s. I ordered them and installed them once I got them. Reading a post recently, I saw someone talking about maintaining proper valvespring height. Can someone please explain the reason behind this, possible problems that can occur, and the right way to determine and set the right height. I installed the springs on the spacers that were used for the previous springs. Can I cause possible damage to the motor? I called ARE today but they weren't able to tell me what kind of springs they installed or what the correct height should be. Please help. Sorry for the lenght of the post.

 

The reasons for this is because the spring should match the cam, if the springs are installed improperly it may not be able to properly take the lobe of the cam without floating valves or other issues. You actually can play with spring seat height if you know what your doing, but you have to look at the math and come up with an excuse to do so.

If the cam you have recommends x and y pounds of pressure (closed/full lift), then you can test a spring and see at what height these measurements are obtained at that are acceptable, and go from there.

 

Go to Crane Cams website, they have an excellent explanation and pictures on how to measure correct spring height.