The performance of your engine can hinge on the quality of your valve springs. These small and often overlooked components are responsible for keeping your lifters in contact with your camshaft. Once your valve springs become worn out and brittle, they will need to be replaced right away if you want to keep your vehicle at peak performance. There are five things you need to bear in mind when shopping for new valve springs.
5 crucial valve spring specs
- Free length - This is the total length of your valve spring when it is neither installed nor under compression. It's measured by taking the total end-to-end length of the unloaded spring. This measurement directly affects the amount of pressure it exerts on the valve seat once it's installed.
- Installed height - This is the total length of the spring after it's been installed (with its retainer and all the necessary components attached). This is measured by taking the distance between the outer edge of your spring retainer and the bottom of the valve shims. The valve shims can be used to alter the installed height.
- Installed load - This is the amount of force exerted by the spring against the valve seat after it's been installed and with the valve completely closed. This is also known as seat pressure.
- Open load - This is the total amount of pressure applied by the valve spring when the valve is at its extreme open position. This value is directly affected by the overall design of the springs.
- Coil bind - This is the state wherein the valve spring is as fully compressed as possible and its coils are in contact. The amount of space between the coils before it's put in that state is equivalent to how far the spring will allow the valve to open.
Knowing these specifications will allow you to select the right springs for your vehicle.
Valve spring design
Other than the aforementioned specifications, it is also worth noting what kind of valve springs you should get depending on the kind of driving you will be doing. For example, titanium valve springs are designed for the short-term needs of high-performance drag racing competitions. Helical round wire springs, on the other hand, are far more common and are used for more casual driving.