Cam Lift Question

[357windsor]

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

[Strtracer]

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]

Cool thanks!

[357windsor]

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

[billydroveit]

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]

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]

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]

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]

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]

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