M20 camshaft lift measurement

[salty]

hey guys
i have a high lift camshaft from a friend which i dont have any idea about the brand or the lift degree :|

i dont really care about the brand i am more interested in the degree

i was searching around to find out and i cam up with this

https://www.youtube.com/watch?v=D0WaGnhklso

went for a second search for the rocker arm ratio i found a lot of different answers but the most common was 1.25

can anybody confirm on my conclusion
please correct me if am wrong

thnx

[e21jps]

its not so easy on an m20 because the ratio changes as lift rises. You really need to install the cam in an old old fit a light valve spring set the correct lash and rotate the cam with a dial gauge on the retainer, its the only way to get a true measurement.

If you have a degree wheel you can fit this to the front of the cam and measure the duration too (need to double the number to get crank degrees) Then you will know exactly what cam you have. Just measuring the lift gives you some indications but doesnt really tell you a lot.

[TobyB]

What e21 said. The only real way to compare cams is to degree them in a head.

I measure valve lift and timing, and ignore the rest, as I don't make cams.

Honestly, it's almost easiest to do it when the engine's together- then you
stick a timing wheel on the nose, a dial indicator in- line with the valve, and roll
it over 720 degrees.

The issue is that our 'tappets' have that curved shape, so when the lobe
goes up the inside, the ratio's lower (as in, 1:1.2) and as it goes off the outside,
it's a lot higher (like, 1:11.3) But it's not quite linear... and inlet valves are on
one side, while exhausts are on the other.... so in- head just eliminates a lot of variables.

t