What is Meant by Degreeing the Camshaft, and Why is it Necessary?
The term "Degreeing In Your Camshaft" means you are making sure the camshaft's position in the engine coincides with that of the crankshaft, so that their rotation is synchronized. This is the only way you will know if the rise and fall of the pistons properly matches the opening and closing of the valves, so the engine will run properly. A few degrees of misalignment can affect the engine's operation dramatically.
If the circumstances were perfect, one would only need to line up the marks on the timing chain sprockets and the cam would be degreed. In reality, you are dealing with a group of components
(the camshaft, crankshaft, timing chain, and sprockets), all with their own standards and tolerances. If these tolerances stack up against you, it could throw you out of alignment. Without degreeing the cam you can never be sure that the parts are in correct position. If you have the tools and expertise, we
always recommend that the camshaft's position in the engine be degreed in.
Is There More Than One Way to Degree a Cam, and Which is Better?
Currently there are two popular methods for degreeing a cam: the centerline method, and the duration at .050"lift method. We believe it is far better to degree the camshaft with either method than not to degree the cam at all; but of the two methods, the duration at .050" lift is much more accurate.
The main problem with the centerline method is it has you finding the theoretical centerline of the intake and/or exhaust lobe and line up on it. It makes the basic assumption that the lobe you are checking is symmetrical, with its opening side being the exact same shape and size as the closing side of the lobe. The truth is that most modern lobes are asymmetrical, with the opening side of the lobe being much more aggressive and the closing side being gentler.
Therefore, when you attempt to locate the middle (or centerline) of the asymmetrical lobe there is an automatic
error factor. It could be as little as 2° off or as much as 6°, depending on the exact lobe shape and the procedure used during the degreeing operation. Neither does it verify that the camshaft has
been properly ground with the correct duration lobes, which can drastically affect performance.
Since the duration at .050" lift method is not affected by the asymmetrical lobe design, we believe it is the more accurate way to degree.
What Tools Will I Need to Degree the Cam?
The basic tools required are:
1. A degree wheel. (You can also use a professional fully
degreed damper or hub, or install degree tape to your stock damper. Be sure to
get the tape that matches the diameter of the damper. Use whatever will give you accurate
markings for 360°.)
2. A stable pointer that can be conveniently mounted to the engine.
3. A dial indicator with at least a half inch of travel in .001" increments. A rigid stand that mounts to the
engine or with a magnetic base to hold the dial indicator will also be required.
4. A positive stop device to locate T.D.C. (You can make your own by using an old spark plug. Remove the porcelain insides, then drill and tap the interior of the spark plug housing and thread a long bolt through it.)
How Do You Find Top Dead Center (T.D.C.)?
2. Clean off any excessive lubricant from the lobes and lifters
that you are checking. Thick oil, especially assembly lube (paste) can cause false readings to occur. Wipe the parts clean before checking, and remember to re-lubricate them when you are