Degreeing Our Four-Valve Modular Motor Camshafts - Power Puzzle - Degree Four-Valve Cams

Now it is time to check the lobe centerline against the numbers on your cam card. Rotate the crankshaft clockwise until you reach the valve's maximum lift and zero-out your dial indicator. Now, rotate the crank counterclockwise until you have dropped at least 0.100 of an inch in valve lift. Spinning the crank clockwise again, turn the engine until the dial reads 0.050. This may seem like an extra step, but it is important to always get your numbers with the crank turning the same direction as it will when it the engine is running. This eliminates the possibility of slack in the timing chain throwing off your readings. Once you have the indicator on 0.050, take a reading from the degree wheel. Most degree wheels allow you to measure in degrees from TDC (the "0" mark) in both directions. Count the degrees from TDC to your pointer along the shortest path (your reading will always be less than 180 degrees). Once you have that measurement, rotate the engine clockwise past maximum valve lift until it has dropped 0

If your readings are off, the only way to make an adjustment is actually to build a little "slop" into the timing system. You can do this by grinding some material off of the sides of the tabs on the cam sprockets. If you need to advance the cam (centerline number higher) then grind the tab so that the sprocket can be rotated more clockwise. If the cam needs to be retarded, do the opposite.

If you've done it correctly, once you put the sprocket back on the cam you should be able to wiggle it back and fourth ever so slightly.

If you need to re-compress the spring tensioners, use a small screwdriver to release the lock while squeezing the ends together and then insert your paper clip back in the hole again to hold the lock open.

Most aftermarket cams, like these from Comp Cams, have a hex that allows you to get a grip on the cam with a large crescent wrench. Leave the bolts holding the cam sprockets against the cam loose and use the crescent wrench to advance or retard the cam slightly to get the lobe centerline to match up with your cam card. Since valve movement can be slow around max lift, the easiest and most accurate method is to check the cam timing at 0.050 of an inch of lift against the cam card. If, for example, your cam card says you should have 0.050 of lift at 236 degrees (this number is totally made up) and you show 0.050 lift at 228 degrees, then you know you need to advance the cam eight degrees. Being careful to hold the crank in place (it helps to have an assistant here), locate the crank at 236 on the degree wheel and use the crescent wrench to adjust the cam so that you have 0.050 of lift at the valve. Once you get it, make sure to hold the cam securely while you tighten the cam sprocket back down to the correct t