A screw-shaped camshaft is a type of variable mechanical valve actuation system ( VVA ) .
A helical camshaft is a type of mechanical variable valve actuation ( VVA ) system .
A helical camshaft is a type of mechanical variable valve actuation ( VVA ) system .
Write a paraphrase for the sentence: A screw-shaped camshaft is a type of variable mechanical valve actuation system ( VVA ) . Output: