Degreeing a Camshaft for Accuracy - Positioned For Power
CHP Step By Step
From the June, 2011 issue of Chevy High Performance
By Sean Haggai
Before you install the spark plugs, drop in the distributor, plumb the carburetor, and fire then engine; making sure the valvetrain is in complete harmony with the harmony with the rotating assembly should be the first priority. It’s a crucial step, too, since engine output is directly affected by the camshaft’s control over the valvetrain.
Camshafts are specifically designed from the manufacturer to open and close the valves at precise times during the rotation of the crankshaft, allowing the correct amount of air/ fuel in, and exhaust out. Verifying the camshaft’s position in relation to the crankshaft will not only prevent the valves from hitting, but also ensure that your build makes peak power as it was designed.
While degreeing a camshaft isn’t absolutely necessary for the average street build, the purpose of this practice is to correct the errors and tolerances in the machining processes of the engine. It also corrects any variances the timing chain, or for race builds, a beltdrive would create. To make up for these inaccuracies and to degree the camshaft correctly, we’ll need to measure 0.050 inch on both sides of the camshaft lobe to find our camshaft centerline. It’s the simplest method and doesn’t require any special tools, but it does require a small amount of arithmetic.
For seasoned builders, degreeing a camshaft has become second nature, and in some cases, only takes them a couple minutes to complete. For the rookie wrenchers, tackling the job alone can be an intimidating process. Don’t worry; we’ve illustrated how to degree a camshaft in the following pages to help make the job a little less stressful. In the end, degreeing a camshaft is well worth the extra time and will yield your build with great results and peace of mind, too.
 We started by installing...
 We started by installing a degree wheel, turning the crankshaft to get the number one piston near TDC, and then positioned the pointer to read zero on the degree wheel. Next, we placed a piston stop over the number one piston.
 We then rotated the degree...
 We then rotated the degree wheel over to either side of the piston stop and noted the number. In our case, we recorded 311/2 degrees on both sides; as long as the degree wheel shows the same numbers on both sides, we’re at TDC. From there, we applied assembly lube to the camshaft and slid it in.
 Next, we removed the degree...
 Next, we removed the degree wheel, applied a light film of oil to the crank snout, and installed the lower gear in the -2 (retard) position on the crank snout.
 We used a double-roller...
 We used a double-roller timing set with a Torrington bearing. Before installing the camshaft gear to the cam, you’ll also need to add a bit of oil to the bearing.
 Before we could begin...
 Before we could begin the calculations, we had to install a set of the lifters. With the lifters in place, we set up our dial indicator to the deck of the block. Note: Make sure the dial indicator has enough runout to prevent any bind.
 To find maximum lift from...
 To find maximum lift from our camshaft, we turned the engine clockwise until the dial indicator showed its maximum value (0.331 inch) just before it began to fall back in the opposite direction.
 To find our max lift value...
 To find our max lift value after TDC, simply subtract 0.050 inch from 0.331 inch, which comes out to 0.281 inch.
 Then, we continued to...
 Then, we continued to rotate the motor carefully in a clockwise fashion until the dial indicator read zero. This puts us back to square one, and we could begin to find our next value. Note: It’s not necessary to rotate the motor counterclockwise.
 To get our next reading,...
 To get our next reading, we rotated the engine over until the dial indicator showed we were now at 0.281 inch. We then recorded the value at the degree wheel; in our case, it showed 66 degrees.
 Similar to getting the...
 Similar to getting the earlier readings, we rotated the engine until we achieved max lift on the dial indicator. Once the indicator began to roll backward, we recorded that value from the degree wheel again. In our case, our degree wheel showed 157 degrees.
 The last step is simple...
 The last step is simple and all we had to do was add the two values (66 plus 157 degrees). The final number gave us a total of 223 degrees that we divided by two, revealing 111.5 degrees. Checking our COMP Cam’s card, we were within 0.5 degrees; that’s it, our cam is set and ready for the remainder of the engine assembly. CHP
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