CAM LOBE HEIGHT

[steamgas]

CAN SOMEONE TELL ME THE CAM LOBE HEIGHT OF A 1952 BUICK 263 CI.ENGINE STRAIGHT 8? OR CAN SOMEONE POST A PICTURE OF A ENGINEERING DRAWING THAT SHOWS ALL THE MANUFACTURING DE-MENTIONS?

[NTX5467]

What you can do is find the "valve lift" spec for the cam.  Then find the rocker arm ratio for the rocker arms.  I suspect these specs could be in a factory service manual?  

 

Once the valve lift and rocker arm ratio are know, then divide the valve lift by the rocker arm ratio to get the "lobe lift" of the cam lobes.  Intake will usually be different than Exhaust.

 

The BEST way to check the Lobe LIft is with the cam in the engine block, dummied-up with a lifter on the particular lobe, then get a magnetic base dial indicator with a pushrod between the lifter and the plunger on the dial indicator.  Turn the engine over and watch the dial indicator needle move.  With the lifter on the "heel" of the cam, "zero" the indicator gauge, then spin the cam until a "max lift" value is achieved, repeatedly.  Then go to the other lobe next to that one.  Repeat the set-up and cycle.  With these Lobe Lift numbers, multiply by the rocker arm ratio to get to Valve LIft.

 

IF you are careful, you might use a digital-readout caliper.  Measuring the "non raised" area of the cam lobe, then rotating around about 90 degrees to get the max lift section of the lobe.  Subtract the smaller number from the larger number.  To me, this method can get you close, but not as accurate as the "in block" method I described above, which I've done on an engine I have, to evaluate valve lift profiles of several cams.

 

NTX5467

[steamgas]

thank you sir for your information. i have setup a dial indicator just as you mentioned. what i need is the factory spec. for the lobe high on a brand new cam. i need this for my base line to compare all my other findings too.