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.
What is meant by Basic RPM? The camshaft's basic RPM is the RPM range within which the engine will produce its best power. The width of this power band is approximately 3500 to 4000 RPM with roller lifter cams.