I had the machine shop install the 4 degree advance key on my cam shaft and they fixed the gear runout issue today. I also came up with a better piston-stop tool, which worked better than the screwdriver method I had used earlier. I used a brake spring removal tool, which after inserting in the #1 sparkplug hole, was held tight in place with the rocker stand using a large zip-tie. After determining TDC and adjusting my degree wheel I went on to check camshaft timing. I am using the Intake Centerline method, which was outlined in my CompCam Degree kit. This method measures the total duration in degrees between the 0.050" position on either side of the cam lobe and then divides this value by 2. 52pu gave my the cam spec of 206, which is the total duration (Not divided by 2). With the straight cam key I originally came up with 205 degrees, which is pretty much on spec. Now with my 4 degree offset key installed I came up with a total duration of 192 degrees. CompCam uses the total duration divided by two to figure how far a cam is advanced or retarded. Therefore 206/2=103 & 192/2=96, and the difference 103-96 = 7 degrees advanced. If my original measurement of 205 was accurate, that would still make my cam 6.5 degrees advanced. My questions are 1) why if I installed a 4-degree offset key, am I getting almost twice that amount? 2) How will this 6.5-7.0 degree advanced cam timing effect my engine performance?
