2003 VALVE SPRING CATALOG, 26000 Series & Pro PAC®...

COMP Cams® Performance Valve Springs
COMP Cams® has always been involved in the development of new spring designs, new materials and new processing technologies and continues to bring the best possible valve springs to the market place. Consequently, our customers are always able to take advantage of the cutting edge. From the time that the wire is made at the steel mill to the time that we place our valve springs in our customers hands, we put as much care as possible into our parts. This ensures that each and every customer can be confident that when they see our name on the box, there are only high-quality parts inside.

COMP Cams® uses only the best Super Clean materials in our valve springs because the requirements are more stringent than for any other application in the world. Metallurgist at the steel mill and spring manufacturing plant have devised methods of taking raw materials and turning them into the spring materials that only COMP Cams® has access to using. 100% of our valve spring wire is eddy current tested to check for surface defects twice. The wire is tested after the drawing process is performed and again just before the spring wire is fed into the spring coiler. Our valve springs are processed in a dedicated cell utilizing the latest in CNC equipment. This dedicated cell only produces springs made to the exacting tolerances of COMP Cams® . Each spring is CNC coiled, stress relieved, ground, shot-peened and heat set by only the best people, dedicated to that work cell and to producing consistent and accurate parts. Metallurgist at the spring plant are constantly performing destructive and non-destructive tests after each process to be sure that every spring made is as good as the last. These tests are performed on sophisticated equipment such as a Servo Hydraulic Cycle Tester, Scanning Electron Microscope and X-Ray Diffraction Residual Stress Machine.

We design our valve springs for specific applications because there is no such thing as a one-size-fits-all valve spring. Valve train components are matched by testing the dynamic interactions between them using a cycle tester, strain gages, load cells, laser displacement transducers, high-speed videos and more. By doing this, we can assemble the best combination of parts for an application by reducing the stresses and increasing the life of each part in the system. We do all this so our customers can be sure they have the correct and best part for their engine.

Every batch of every part number is statistically tested when received to ensure consistency and eliminate batch to batch variations. This will help make sure that each time a set of springs leaves COMP Cams® it is the same as the last box of spring sent out in the same part group.

Valve springs are one of the most critical and most over-looked components in your engine. They must be matched to your cam in order for the engine to reach its full potential. It does absolutely no good to install a cam that will RPM to 8000, if you do not have the correct springs. The use of the wrong valve springs is one of the most common causes of engine failure. Another is the incorrect installation of the valve springs.

Valve Spring Checklist
1. Use only the valve springs that will give the recommended spring pressure with the valve both on the seat and at maximum lift.

2. COMP Cams® has matched each set of springs for load consistency. A variance of + or -10% is acceptable for new springs.

3. The outside diameter of the recommended valve spring may require that the spring pocket of the head be machined to a bigger size.

4. One of the easiest and sometimes most costly mistakes made in racing engines is not positively locating the spring. A valve spring that “dances” around on the cylinder head or retainer causes harmful harmonics and excessive wear. A spring that is forced onto a retainer is likely to fail at that coil. That is why we have such a large selection of steel and titanium retainers (page 316-317), hardened steel spring seat cups, and inner spring seats (page 313) to better match our springs. A spring that is contained properly at the retainer and the cylinder head will offer the longest possible service life.

5. With the springs removed from the heads you are ready to check the installed spring height (Diagram A). This is the distance from the bottom of the retainer to the surface where the spring rests on the head. This distance is what the spring sees when the valve is on the seat. The valves, retainers and valve locks will be used in this step. First install the valve in the guide, then install the retainer and valve locks. Pull the retainer tightly against the valve locks while holding the valve assembly steady. Measure the distance between the spring seat and the outside step of the retainer using your height micrometer (part #4928 or 4929) or a snap gage and a pair of calipers. Repeat this procedure for all the valves and record your information. After you have measured all the valves find the shortest height. This will become the springs installed height on your heads. If your combination includes a dual or triple spring assembly, it will be necessary to allow for the inner steps of the retainer.

6. Once you have determined the shortest installed height, it will be necessary to use shims to obtain this installed height (±.020" is acceptable) on the remaining valves. These are available through our catalog or at any of your local COMP Cams® dealers.

7. Before removing the retainers, measure the distance from the bottom of the retainer to the top of the valve seal. (Diagram A). This distance must be greater than the lift of the valve. If not, the guide must be machined. This is a very common cause of early camshaft failure.

8. Once the valve springs have been installed, it is important to check for coil bind. This means that when the valve is fully open there must be a minimum of .060" clearance between the coils of both the inner and outer springs. If this clearance does not exist, you must change either the retainer or the valve to gain more installed height, or change to a spring that will accommodate more lift or machine the spring seat for extra depth.

9. When installing the springs you must make sure that the correct retainer is used. The fit between the retainer and the spring may be snug, but excessive pressure should never be used to install the retainer.

10. Always check for clearance between the retainer and the inside face of the rocker arm. This will be most evident while the valve is on the seat. Rocker arms are designed to clear specific spring diameters, so you should check to see that you have the proper rocker arm / retainer combination. This situation can also be the result of improper rocker geometry, and may be corrected with different length pushrods or a different length valve.

11. It is important for new springs to take a heat set. Never abuse or run the engine at high RPM when the springs are new. Upon initial start-up, limit RPM to 1500 to 2000 until the temperature has reached operating levels. Shut off the engine and allow the springs to cool to room temperature. This usually will eliminate early breakage and prolong spring life. After the spring has been “broken-in”, it is common for it to lose a slight amount of pressure. Once this initial pressure loss occurs, the spring pressure should remain constant until the spring becomes overstressed. Then the springs must either be replaced or shimmed to the correct pressure.