Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Cam grind numbers
View Single Post
  #5 (permalink)  
Old 02-12-2013, 10:14 AM
vinniekq2's Avatar
vinniekq2 vinniekq2 is online now
Registered User
Join Date: Jun 2012
Location: BC,Canada
Age: 59
Posts: 11,642
Wiki Edits: 0

Thanks: 694
Thanked 1,340 Times in 1,243 Posts
duration is the length of time that the valves are open
you need to have the valves open long enough to fill the cylinder.
think of filling a jar under a tap
when its full some flows back towards the top or splashes back

now put the lid on this jar,shake it and walk into another room,open the jar and pour out the water in another sink

how fast you fill the jar depends on the neck size or opening size(valve size in an engine)the water pressure from the tap and tap size (intake runner size)
lid on as soon as the jar is as full as possible without spilling

empty jar by turning upside down with lid off(think of a long neck pop bottle Vs a short neck pop bottle for exhaust)put lid back on as fast as possible so you can go back and refill at tap.
any wasted time and spillage is cam/head/carb/header inefficiency
Reply With Quote