{"id":7983,"date":"2014-09-16T14:38:47","date_gmt":"2014-09-16T21:38:47","guid":{"rendered":"http:\/\/www.racingjunk.com\/news\/?p=7983"},"modified":"2016-11-30T15:20:13","modified_gmt":"2016-11-30T23:20:13","slug":"valve-springs-primer","status":"publish","type":"post","link":"https:\/\/www.racingjunk.com\/news\/valve-springs-primer\/","title":{"rendered":"Valve Springs Primer"},"content":{"rendered":"

Drag Race 101: Valve Springs Primer<\/strong><\/p>\n

Valve springs are probably the most overlooked part of the valve train when building an engine, whether it\u2019s a daily driver econo-car or a full-blown race car. This is a shame, especially when you take into consideration how many times engine failures during a race or pass are traced back to faulty springs. If it can happen to engines that are meticulously engineered to the finest detail, it can very easily happen to yours.<\/p>\n

\"Image<\/a>
Image via Comp Cams<\/figcaption><\/figure>\n

We\u2019re going to discuss valve springs in some detail. We\u2019ll first tell you where they\u2019re located and what they do. I will next go into some detail on how valve springs can fail. There are a couple different designs that are used for valve springs, so next I\u2019ll jump in and give those a mention. After that I\u2019ll mention some of the most popular brands that are available, and finally, I\u2019ll give two short How-Tos on how to remove and replace (R&R) valve springs, both with the engine together, and disassembled.<\/p>\n

What Are Valve Springs and What Do They Do?<\/b><\/p>\n

<\/b>As their name implies, valve springs are springs that are used in conjunction with the engine\u2019s valves, both intake and exhaust. As the camshaft turns, causing the valves to open and close, a force outside the pressures generated in the combustion chambers is needed to cause the valves to close quickly and completely when the cam lobe rotates to the proper alignment. We use valve springs to perform this function.<\/p>\n

The valve spring is located in the top of the engine cylinder head and there is usually at least one valve for exhaust and one for intake per cylinder, although most high performance engines have multiple intake and exhaust valves per cylinder. The valve springs surround the valves and can be found either between the rocker arm and the head in cam-in-block engine designs, or between the camshaft and the block in overhead cam designs. The valve is inserted in the valve guide from the\u00a0 underside, the spring is installed and compressed, a set of locking clips are installed to retain the spring, and the spring is decompressed.<\/p>\n

\"Photo:<\/a>
Photo: jegs.com
An example of chamfer or interference-fit valve springs showing the internal and external spring.<\/figcaption><\/figure>\n

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How Valve Springs Can Fail<\/b><\/p>\n

A valve spring is said to have failed when it is no longer able to properly seal the valve against the seat every revolution of the camshaft. This can happen in a number of different ways, but there are two main ways this happens:<\/p>\n