How is a cam's "advertised duration" measured?
#1
How is a cam's "advertised duration" measured?
I've been trying to figure this out, but still don't clue. How is "advertised duration" measured? I've been trying to compare some import cams to my LE custom grind, such as the famous HKS "272/272" cam which doesn't even tell you the duration at .050 lift. I understand how duration is measured from .050 inch lift, which makes sense, but don't fully understand what advertised duration can be measured. Also was trying to figure out why these imports have barely any lift on their cams, what would be the purpose of running a lot of duration with only .400 lift? I've been looking at cams for my SI (daily driver) and the cam I am looking at is around 250/252 duration @ .050 lift, but still only has .510/.470 lift even with that much duration, I was trying to figure out why that wouldn't be a higher number.
#4