Valve springs are one of the most critical and most overlooked components in your engine. Proper selection of the valve spring begins with identifying the application and selecting all of the valve train components to achieve the engine builders’ goals.

The spring is selected to complement the system and must be matched with the entire valve train 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. Improper selection of the wrong valve spring is one of the most common causes of engine failure. Other common causes are the incorrect installation and improper handling of the valve springs.

Selecting a Spring
1. Use only the valve springs that will give the correct spring pressure with the valve both on the seat and at maximum lift.

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

3. 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 (pages 308-309), hardened steel spring seat cups and I.D. locators (page 312) 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.

Proper Spring Handling
1. Handle springs with care. Never place in a vise, grab with pliers or hit them with a hammer. This will damage the surface of the spring, which will cause a spring to fail.

3. Valve springs are shipped with a rust preventative coating that should remain on the spring throughout engine assembly. Do not clean springs with acidic or evaporative cleaners. This causes rapid drying and promotes the formation of rust on the surface, which can cause catastrophic failures. Even a slight amount of corrosion can grow to be a problem.

4. When installing springs, use COMP Cams® Valve Train Assembly Spray (Part #106) to ease assembly
and improve the life of the spring.

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

2. When checking the spring loads on a load tester (Part #5313) measure and note the thickness of the retainer where the outer spring sits. Assemble the retainer on the spring and place on the base of the spring checker.

3. Compress the spring to the desired installed height. This is the measurement between the top of the spring (on the bottom side of the retainer where the outer spring sits) and the bottom of the spring on the base.

* NOTE *
Since the retainer is installed in the spring when checking the spring loads, make certain that the thickness of the retainer is not included when calculating the installed height and is accounted for when compressing the spring. The spring load checker will show to be higher with the spring installed at the correct height.

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