Ama-valves uvemvane amabili, aziwa nangokuthi ama-valve avemvane asebenza kakhulu, Idlala indima ebalulekile ezinhlelweni zezimboni lapho ukulawulwa kokugeleza kubalulekile. Ngokungafani nama-valves wendabuko uvemvane, i-eccentric ephindwe kabili ifaka i-offset disc ne-shaft enikeza amakhono okubeka uphawu nokunciphisa ukugqoka ngokuhamba kwesikhathi. Lo mklamo oyingqayizivele uvumela ukusebenza okusebenza kahle,