How to Degree a Cam With the Heads Removed

Find your own cam degree wheel by clicking here.

Degreeing a cam is something that should be done when building any performance engine.  Degreeing your cam will verify that the cam company ground the cam correctly, and it will also allow you to accurately make changes to the cam timing if you desire.  You will need a dial indicator, a piston stop, and of course a degree wheel.  You can buy degree wheels or you can make your own (if you have the proper tools).  The following photos will show you the steps that I took to degree my cam.

In order to degree a cam it is critical to find top dead center.  Top dead center  (TDC) is when the intake and exhaust valves are completely closed, and the piston is a the highest point in its stroke.  The piston has a few degrees where it does not move up or down when the connecting rod is changing directions.  The midpoint of these degrees of no movement is TDC.

The 1st step in finding TDC is to install a piston stop.  A piston stop is nothing more than a thick piece of metal that is bolted across the cylinder.  There is an adjustable stop that is threaded into it.  Rotate the engine until the piston is just below the deck on the compression stroke (both valves closed).  Screw in the adjustable stop until it makes contact with the piston.

Now it's time to install the degree wheel.  This is a degree wheel that I made.  You can make your own or buy one.

Now bolt a piece of wire to the block and bend it so that it points at the degree wheel.

Spin the engine in one direction until in makes contact with the piston stop.  Write down the number that the indicator is pointing at.

Spin the engine in the opposite direction until the piston hits the stop.  Write down this number.  TDC is the degree in between the two numbers that you wrote down.  Back off the piston stop and rotate the engine to the degree between the two numbers that you wrote down. ( Example  if your 1st number was 10 degrees after TDC and your second number was 20 degrees before TDC then the number in between those two degrees is 5)  Once you have the engine rotated to that midpoint readjust the degree wheel so that the pointer is pointing at the TDC mark.  Your engine is now at top dead center.

This is what it should look like.

I then removed the degree wheel so that I could mark the harmonic balancer's TDC.  You will not have to do this if your timing marks are visible.

The timing marks on my harmonic balancer were removed when I was preparing it for paint.  Therefore, I had to install timing tape.  Since I knew that the engine was at TDC this was a good time to install the tape.  This harmonic balancer is designed to work with different timing pointer configurations, so with the engine at TDC I could see which mark worked with my timing pointer.  I took a center punch and marked the balancer at the corresponding TDC mark

I also wrote TDC on the front in chalk

In order to use a dial indicator on a lifter you must give the tip of the indicator a flat surface to rest on.  I simply welded a bolt to the lifter.

Now I reinstalled the degree wheel, and mounted my dial indicator. 

Rotate the engine until the intake lobe is "open" the entire way and zero the indicator.  You know that the lobe is at its highest point when the dial indicator reaches its highest reading  You need you cam card for the rest of this process.  If you do not have your cam card you should be able to find it online simply be entering the cam part number into the manufacturer's website.

Next you want to verify the center line of the cam.  This process is similar to finding TDC.  Rotate the engine until the intake lifter moves down .050".  Write down what degree the pointer is pointing at on the degree wheel.  Spin the engine the opposite direction until the lifter moves down .050".  Write down this number.  The degree in between those two numbers is your cam center line.  This should match the center line degree mark on your cam card.  If it doesn't, you can advance or retard the crank sprocket to match the correct center line number.  You can also advance or retard the engine to meet you own needs.

Next I verified that the valves open when they are supposed to.  On your cam card it will tell you at what degree you valves should open.  You also need to know your valve timing number.  My valve timing number was .006".   So when my lifter moves .006" the degree wheel should match the degree on the cam card for when the exhaust valve is supposed to open. Next  I rotated the engine until the exhaust valve was down.  Then I positioned the dial indicator on the end of the modified lifter.  Once in position I zeroed the indicator.  Finally I rotated the engine until the lifter  moved .006".  I then looked at the degree wheel and verified that it was opening at the proper degree.

To check the duration first set the cam so that the lobe is in its closed position.  Set the dial indicator on the modified pushrod and zero it.  Duration is usually advertised at .050".  Rotate the engine until the dial indicator reads .050".  Write down what degree the wheel is at.  Continue to rotate the engine until the dial indicator again reads .050".  Write down what degree the wheel is at.  Determine the number of degrees between the two numbers that you wrote down.  This number should match your advertised duration@.050" lift.

Repeat the same procedures on the intake valve.  Your cam is now degreed.