How do you measure max lift on a set of cams?

Crim · 05-12-2004, 06:56 PM

I used the search but didn't come up with much of use.

Anyone care how to explain how to measure max lift on a set of cams, trying to determine if these cams are S3's or just OEM DE cams (They're not marked in any way)

Crim · 05-12-2004, 06:58 PM

I have a set of calipers btw...

A friend said to measure the smallest diameter on the lobe, and then the largest, largest - smallest, but I came up with something like 6mm that way.

I measured the camshaft, and then measured the camshaft + highest point on the lobes, subtracted the two and got ~11mm, which sounds about right for S3's...

am I totaly wrong in how I'm going about this?

SlateBlueSR20 · 05-12-2004, 09:27 PM

Sounds like you are doing it right, but the measurments seem off...measure one of the lobes and then subtract the base circle (32mm)....this will give you cam lift.

Or if you just want to measure one of the lobes, it should be around 39.2mm on the S3 and a little bit less on a stock cam.

Josh

honkeybizkit · 05-12-2004, 09:42 PM

you measure the base circle, then the highest point on a lobe, then you have to multiply that measurement by 1.6 (rocker arm ratio)... so if you had 6.xxmm the lift would be like 9.xx-10.xx.

Slartibartfast · 05-13-2004, 12:22 PM

Don't forget that a lot of manufacturers specify valve lift at 0.05" lift to make sure any slack has been removed.