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Drivetrain => The Nailhead => Topic started by: dlmwtvl on January 07, 2017, 09:59:59 AM
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Hello,
Can someone tell me what is the max cam lift, where port flow stops increasing on the stock heads.
Also, the same question with the larger 194/155 valves.
Certainly no sense putting a .510 lift cam in, if the port flow wont support it.
Sincerely,
David
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I see you just posted on V8 too. Should get some knowledgeable replies there.
http://www.v8buick.com/showthread.php?317533-1966-401-374603-cylinder-head-flow-question&p=2645851&posted=1#post2645851 (http://www.v8buick.com/showthread.php?317533-1966-401-374603-cylinder-head-flow-question&p=2645851&posted=1#post2645851)
Flow at max lift isn't the important factor. You want the valve open LONGER at the lift where there is the best flow. I'll guess that's roughly around 0.500". To do that, you have to overshoot that lift number.
An ideal cam lobe would have a 'square' profile..... open valve to 0.500", keep it there, then close. Square lobes don't work so that's why higher lifts are used!
Concept is commonly referred to as 'area under the curve', except you are only looking at the area under the 0.500" height.
Would be far easier to explain if I could draw a picture...