That is my question. I have 1.5's and have a cam that has .480/.480 lift. What will 1.6 rockers bring my lift to and how do you come up with it? I'm sure alot of people can use this. Thanks

Divide by your current ratio and multiply by the new ratio. You'll be at .512.

cool, thanks.

(cam lift / stock rocker ratio) x aftermarket rocker ratio = total lift

example (.480 / 1.5) x 1.6 = .512

This should be put in the equations list, since more and more people are going to higher ratio rockers without changing valve springs.

Maybe it could be in the equations list, but no offense or anything but it's basic arithmetic.

Yes it is basic math once you know what to do with the numbers. I spent a good five minutes trying to figure it out and gave up, so I asked. I'm sure there are alot of people who feel confident in their arithmatic without having a second opinion, I however am not one of them. On the other hand, some people don't even know how to figure out the radius of their tires, so our site instructs them to do so. Wouldn't it be nice to give a formula to those who aren't sure of themselves, so them they can understand how they got their answer? But thanks alot or the help, I'm glad I understand now how to calculate total lift.

Here is another way.

Simply multiply the gross lift @1.5rr by 1.0666
This will give you the new lift with a 1.6rr

.480" X 1.0666 = .512"

Damn, man--I had to make it into a first-order linear ODE system and use Laplace transform.

The third worksheet on this spreadsheet gives lift, duration, timing, and acceleration rates of the valves with varying rocker ratios:

Engine Calculator.xls