Advance or retard ignition timing tuning on a built GM Quad 4 W41 2.3L DOHC quick-burn engine Running a 200 shot ZEX nitrous kit in a 1992 Oldsmobile Achieva SCX W41.

Unfortunately, many small overhead cam mills utilize a timing belt to drive the camshafts (as opposed to a more durable timing chain), making them interference engines.