Detroit Racing Forums

Detroit Racing Forums (http://www.detroitracing.com/forums/index.php)
-   The Shop (http://www.detroitracing.com/forums/forumdisplay.php?f=6)
-   -   Cam Lift Question (http://www.detroitracing.com/forums/showthread.php?t=2300)

357windsor 11-14-2005 11:17 AM

Cam Lift Question
 
How do you figure lift w/ different rocker ratios. I know there's a formula to figure this out. Anyone know it?

Strtracer 11-14-2005 11:59 AM

Quote:

Originally Posted by 357windsor
How do you figure lift w/ different rocker ratios. I know there's a formula to figure this out. Anyone know it?

simplified way. devide by stock ratio, then mutiply by new ratio. ie, if lift is .450 at 1.5 and you want lift at 1.6.---.450/1.5=.300. .300x1.6=.480

357windsor 11-15-2005 09:26 AM

Cool thanks!

357windsor 07-11-2007 10:26 PM

Shouldn't this be made into a sticky here? I'm sure someone else is gonna ask this question. Just a thought.

billydroveit 12-13-2008 11:34 PM

Quote:

Originally Posted by 357windsor
Shouldn't this be made into a sticky here? I'm sure someone else is gonna ask this question. Just a thought.

Most people don't know going with a longer ratio rocker adds duration. See Comp Cams for clarification, they have a great tech article on this somewhere.

johnquick302 12-13-2008 11:58 PM

you can mess with the duration with lash too. every .004 is 1 deg of duration.

if you have a cam card you can multiply lobe lift by the rocker arm length. if it says .450 you multiply that at 1.6 and it equals .720 lift or 1.7 is .765

357windsor 12-14-2008 01:02 PM

Quote:

Originally Posted by johnquick302
you can mess with the duration with lash too. every .004 is 1 deg of duration.

if you have a cam card you can multiply lobe lift by the rocker arm length. if it says .450 you multiply that at 1.6 and it equals .720 lift or 1.7 is .765

Thanks, never knew that!

billydroveit 12-15-2008 09:28 AM

Quote:

Originally Posted by johnquick302
you can mess with the duration with lash too. every .004 is 1 deg of duration.

if you have a cam card you can multiply lobe lift by the rocker arm length. if it says .450 you multiply that at 1.6 and it equals .720 lift or 1.7 is .765

Does that pertain to Solids only, or does it also affect (most likely not as much) Hydraulics? I.E. Valve lifter preload being .050 if you go to .075 would that affect the duration? Also do you have a tech article on this?

Thanks Roger

(the numbers are just examples)

johnquick302 12-15-2008 10:56 AM

Quote:

Originally Posted by billydroveit
Does that pertain to Solids only, or does it also affect (most likely not as much) Hydraulics? I.E. Valve lifter preload being .050 if you go to .075 would that affect the duration? Also do you have a tech article on this?

Thanks Roger

(the numbers are just examples)

im guessing its only for solid rollers. ronny sharp told me this a few years ago.

billydroveit 12-15-2008 12:53 PM

Quote:

Originally Posted by johnquick302
im guessing its only for solid rollers. ronny sharp told me this a few years ago.

I kinda figured, but i wanted to ask. Thanks


All times are GMT -5. The time now is 07:17 AM.


All posts and images belong to DetroitRacing.net and its owners.