COMP Cams Camshaft Installation and Degreeing Procedure - Manual (Page 10)

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COMP Cams®
3406 Democrat Rd.
Memphis, TN 38118
Phone: (901) 795-2400 Fax: (901) 366-1807
www.compcams.com
Part #145
Revised 5/4/12
rotation) until the piston comes back up and touches the piston stop. Make a mark on the
number the pointer is on.
7. Remove the piston stop after marking the two points on you degree wheel. Rotate the
crankshaft to the midpoint of the two marks. This point is TDC for cylinder #1. Without
rotating the crankshaft, adjust the degree wheel to read 0 degrees at the pointer. You are now
ready to locate the intake lobe centerline relative to TDC. If you are not absolutely sure that
your 0 degree mark is set at TDC, repeat this procedure. This step-by-step is critical to proper
cam alignment.
8. Attach the dial indicator to the dial indicator mount. Position the dial indicator mount so the tip
will contact the retainer of the intake valve. It is important that the indicator plunger be parallel
to the valve stem. Any variance in the angle of the indicator will introduce geometric errors
into the lift readings.
9. Rotate the engine in the normal direction of rotation until you reach maximum lift. The dial
indicator will change direction at the point of maximum lift. At this point, set the dial to zero.
10. Back the engine up (opposite normal rotation) until the indicator reads .100.” Next, turn the
engine forward in the normal direction of rotation until the dial indicator reads .050” before
maximum lift. Record the degree wheel reading.
11. Continue to rotate the engine over in its normal direction of rotation until the indicator goes
past zero to .050” on the closing side of maximum lift. Again, record the degree wheel reading.
12. Add the 2 numbers together and divide by 2. That number will be the location of maximum lift
of the intake lobe in relation to the crank and piston. This is the intake centerline. For example:
The first degree wheel reading was 96 degrees. The second reading was 116 degrees. These
two numbers (96 + 116) added together will be 212. 212 divided by 2 will equal 106. Your
actual intake centerline is 106 degrees. Reference back to your cam spec card and see what the
recommended intake centerline is.
In the event that your camshaft did not degree in as per manufacturers’ specs, it will be
necessary to either advance (move the cam ahead) or retard (move the cam back) the cam to
meet the suggested intake centerline. Depending on the engine application, there are several
different ways for advancing or retarding the camshaft. One common method is by use of a
crank gear with multiple keyways – each one being at a slightly different relationship to the
gear teeth. A second method is to use offset bushings that fit on the cam pin and in the cam
gear. The offset will advance or retard the cam depending on how the bushing is placed on the
cam pin. Another method is by offset keys that fit into the crank gear keyway. A more
elaborate system uses an adjustable timing gear. Contact COMP Cams® for the method best
suited to your application.
Note: When degreeing a cam, remember to look at the degree wheel as a full 360 degrees,
no matter how the degree wheel you are using is marked. Many degree wheels are
marked in 90 or 180 degree increments. On wheels that are marked in 90 degree