Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - can someone please explain cam numbering?

uiuc240 · 01-20-2003, 01:37 AM

yeah, Jeff, he's talking lift in millimeters

so, your 248/11.0 cams are 248 degrees duration, 11.0mm max lift.

make sense? The cam is egg shaped, and the valves stay open for a rather large portion of the revolution...this is where overlap comes in to play. If you have a longer duration, this will inherently give more overlap, seeing as how the valves will be open longer (more time at the same time).

overlap = good for NA, not so important for turbo.

Eric

01-20-2003, 01:37 AM	#5
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0)	yeah, Jeff, he's talking lift in millimeters so, your 248/11.0 cams are 248 degrees duration, 11.0mm max lift. make sense? The cam is egg shaped, and the valves stay open for a rather large portion of the revolution...this is where overlap comes in to play. If you have a longer duration, this will inherently give more overlap, seeing as how the valves will be open longer (more time at the same time). overlap = good for NA, not so important for turbo. Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)