Double Valve Spring

For B18 or B20 heads. One inner and one outer spring. Cylinder head must be flycut for larger diameter of outer spring.

If your machine shop does not have the correct mill for enlarging the valve spring seats for double valve springs, you can purchase one from Isky Cams (part # 208).

Double valve springs are vital for maximum performance above 5,000 RPM. Performance grind cams have steeper slopes on their lobes and consequently the lifters and connected valve train have a harder time staying in contact with the lobe surface. The higher seat pressure and higher spring rate assist in making sure the valves are doing what the cam is calling for. Additionally they offer a safety margin in case one spring breaks the other will keep the valve clear of the pistion crown.