How to Degree Your Camshaft

Align the timing marks by rotating the engine until the crankshaft gear timing mark is straight up in the 12 o’clock position. Install the cam gear on the front of the camshaft. Rotate the cam until the timing mark on the cam gear is pointing straight down (6 o’clock position). Remove the cam gear and slip the timing chain over it. Slip the chain over the crank gear, making sure to keep the timing marks on both gears aligned. Slip the cam gear on the camshaft as before. Snug down the cam bolts, then use a straightedge to verify that the timing marks on both gears are properly aligned with each other.

Step Two: Locating Top Dead Center (TDC) Locating Top Dead Center on a small block Chevy is usually done on the Number One cylinder. Screw the piston stop from the degree kit into the spark plug hole until it contacts the piston and prevents it from moving. If the stop does not go in all the way, rotate the engine until the piston moves far enough down the bore to allow the stop to screw in all the way.

Attach the degree kit’s wire pointer to the front of the block as shown. Slip a crankshaft turning socket over the crank snout (Summit Racing makes a nice crankshaft turning socket). Attach the degree wheel to the socket and tighten the adjusting nut finger-tight. Turn the engine over slowly until you feel the piston firmly contact the piston stop.

Loosen the adjusting nut and turn the degree wheel until the zero degree mark is opposite the pointer as shown. Tighten the adjusting nut.

Rotate the engine in the opposite direction until the piston hits the piston stop again. Note the reading on the degree wheel; in our example, the reading is 62.5 degrees. Top Dead Center for our engine is located exactly halfway between zero and 62.5 degrees, or just past 31 degrees. Make a mark on the degree wheel at that point.

Loosen the adjusting nut again and rotate the degree wheel until the TDC mark is opposite the timing pointer as shown. This will ensure the piston is at Top Dead Center when zero degrees is indicated on the degree wheel.

Locating Maximum Intake Lobe Lift When working on engines with the heads attached, you cannot position the dial indicator and base so the indicator’s spindle is perfectly aligned with the intake side lifter. You can use a pushrod as an extension if you make sure it aligns properly with the dial indicator spindle as shown.

You must use a solid lifter, like one of these from COMP Cams, when checking lobe lift on a solid or hydraulic flat tappet cam. Place the lifter in the intake lifter hole for the Number One cylinder. Rotate the engine until the lifter is on the base circle of the cam, then preload the dial indicator with more travel than the anticipated lobe lift. Set the dial indicator to zero, then rotate the engine two full revolutions until the lifter is back on the base circle of the cam. The dial indicator should now read zero if it is properly anchored.

Rotate the engine until you see the anticipated maximum intake lobe lift on the dial indicator. Adjust the indicator to zero again, then turn the engine backwards until the indicator needle moves just past .050 inch. All valvetrain slack will now be taken into account when you make your measurements. Next, slowly rotate the engine clockwise until the indicator reads .050 inch below maximum lift. Note the reading on the degree wheel and mark it; this was 64 degrees for our sample cam. Continue rotating the engine past the point of maximum lift until the indicator reads .050 inch again. Note the reading on the degree wheel and mark it; our reading was 152 degrees. Add the two readings together and divide by two. For our cam, 64 + 152 = 216 degrees; dividing 216 by two yields 108 degrees. That is the cam’s intake centerline.

Compare the intake centerline you just calculated to the one listed on the cam card. If the measured centerline is greater than the one listed on the card, the cam is retarded. If the measured centerline is less, the cam is advanced. Our cam’s intake centerline is 108 degrees, but the cam card specified 106 degrees. Thus, our cam is two degrees retarded. We installed a two degree cam bushing in the cam gear to advance the cam to the proper position. The bushing fits in the dowel pin hole, with the “fat” side facing up as shown (to retard the cam, the fat side should face down). Snug down a cam bolt opposite the dowel pin, then bring the cam up to the point of maximum lobe lift as outlined previously. Rotate the engine and mark the degree wheel at .050 inch before and after maximum lift. We observed 59 degrees and 153 degrees respectively. Adding these together and dividing by two yields 106 degrees (59 + 153 = 212; 212 / 2 = 106). That is exactly where the cam needs to be.

To finish the task, install the remaining cam bolts and a cam locking plate. Be sure to apply a dab of thread locker on the bolts, and use a small screwdriver to bend over the locking plate tabs. Now your cam is positioned to make the power it was designed to make.