anyone know how to measure a cam

[that national]

so im rebuilding my motor and the cam is supposed to be aftermarket, and i just wanna know for sure so does anyone know how to measure a cam with it out of the car?

 

[breiter]

Some machine shops have a cam spec machine that actually reads the cam lobes to provide the specs. A buddy of mine bought a SBC 383 engine that was supposed to have this awesome 600 plus lift cam in it. The engine had not been run since assembled years ago so we went back through it. The engine shop had a machine to read cams so he paid them $40 to spec the cam. Turned out to be a 450 lift very mild cam. Nothing like expected and he ended up using a different cam. Worth the $40 fee, yea!

 

[87GN_70GS]

The only other method (aside from a cam doctor mentioned above, or an adcole) is you can measure the lobe lift. With micrometers or calipers, measure the peak of the lobe to the base circle, then measure the base circle(the smallest diameter of the lobe). Subtract the 2 and it will give you lobe lift. Mulitply by the rocker ration (1.55 for stock) and you will have valve lift. Do this for an intake and exhaust lobe.

 

[dr_frankenstein]

Umm...........buy a degree kit from summit.

and use an old block and head.

:biggrin: A.j.

 

[novaderrik]

The only other method (aside from a cam doctor mentioned above, or an adcole) is you can measure the lobe lift. With micrometers or calipers, measure the peak of the lobe to the base circle, then measure the base circle(the smallest diameter of the lobe). Subtract the 2 and it will give you lobe lift. Mulitply by the rocker ration (1.55 for stock) and you will have valve lift. Do this for an intake and exhaust lobe.

this method will get you in the ballpark- i don't think that there are too many Buick V6's running in any "strock lift" dirt track classes, so just going by the lift should get you really close to figuring out what cam it is. also look at the ends of the cam- one end might have a grind number in it. it isn't always this easy, but i was once given a blown up 340 Mopar that had a cam that was stamped "HMV 272" on the back end, which told me it was an older Crane 272 cam. if it isn't that specific, just google the numbers you do find and see what you find.

 

[toofastforyou]

Try this: http://www.cranecams.com/pdf/Page658-663.pdf
Might help...

Claude. :wink: