Those little spirally things that seem so simple… are one of the most relied upon components of an engine. Without proper valve springs suited to your setup you run the risk of a catastrophic engine failure!
The valve springs principle function is preventing valve float which is most likely to happens at high engine speeds with aftermarket camshafts with lobe designs more aggressive and more lift than factory camshafts. Essentially at speed the valve train isn’t able to follow the closure of the cam lobe profile and is considered out of control, so a valve would “float” and not close as it should straight away.
Preventing this is done by replacing the factory valve springs with new springs that have a higher rating of seat pressure, open pressure and a higher max lift. Increasing these numbers results in better control of the valve and greatly improved engine reliability. Going to high though can have a negative effect on other components though.
Depending on your intended use and engine build VCM Performance offers 2 styles of upgraded Valve springs; Single Springs and Dual Springs. As their names suggest single springs utilise 1 spring per valve while dual springs uses 2. There are some drawbacks for both types though.
Single springs are a direct replacement to the factory ones with the benefit of being able to support high lift (up to 0.625” with the PSI Performance Singles) with increased seat/open pressure that is not overly heavy or hard working on the rest of the valve train; so valve train components like lifters, pushrods, timing chain etc. aren’t excessively stressed. The concern with single springs is that if in the unfortunate case of a valve spring breaking there is every bit of potential that the valve will drop down into the cylinder and hit the piston –destroying everything! Usually single springs are recommended for daily, weekender style setups, where for the most part the engine won’t be bouncing on the limiter and heavily abused. In saying that they will cop a bit of punishment, but as with any performance engine in general regular checking and maintenance is needed.
Dual Springs do take a little more to get fitted. Having an inner and outer spring means that new seats, stem seals, locks and retainers will need to be changed to suit, which are included in the kits VCM supply. The benefits of a dual spring over a single is if again in an unfortunate event a spring is broken there is a second spring to hold the valve up and prevents it from dropping in to the cylinder. Which does put a lot of peoples mind at ease. Downside is that dual’s generally have a lot more seat/open pressure, and can take its toll on the valve train especially if you’re reusing your factory lifters etc. Duals are commonly used with really high lift camshafts (up to 0.660” with the K-Motion and Manley’s), in full engine builds and in engines being used in racing, burnouts and the like where a lot of revs are sustained for a while.
If you are unsure of which springs would be best suited to your setup, get in contact with us and we’ll help out as much as we can.