Jock itch (tinea cruris) is a fungus, the same one that causes athlete's foot and scalp ringworm. The groin area is the perfect place for the fungi to grow and cause a fungal infection because it is moist, warm and dark.
The camshaft lift is the resultant net rise of the valve from its seat. The farther the valve rises from its seat the more airflow can be provided, which is generally more beneficial. Greater lift has some limitations.
For this to happen, the spring's tension must be great enough to allow the lifter to follow the contour of the cam lobe, at idle and all the way through maximum RPM, for literally millions of cycles. If spring tension is too light, valve float and eventual engine damage can occur. If the spring is too stiff, friction-related horsepower loss and accelerated valve train wear will result. According to cam experts, one of the most common causes of premature camshaft failure is the use of improper valve springs.