Vibration damper error

[Barry Wolk]

While trying to time my car I found that there was a problem with the timing. I was advised to obtain a Top Dead Center tool to check that the pointer lined up with the TDC mark. It did not. It was about 3° off. Two things could have happened. Vibration dampers can turn on the center core leaving the orientation of the TDC mark off by a number of degrees. In my case, 3° was sufficient to induce knocking. Or, the vibration damper could have come off another engine.

The TDC tool inserts into the spark plug threads and has a threaded rod in the center of it. Turn the crank by hand until the marker is at TDC. screw the core in until it touches the top of the cylinder. Rotate the crank about 10°. If you can rotate it in that direction, you're half way there.

Now rotate the crank in the other direction until the top of the piston make contact with the threaded core of the TDC tool. If the core blocks the rotation turn the screw out 1/2 turn and try again. If it clears, you've found TDC. If it doesn't, back the screw off another 1/2 turn, rinse and repeat until piston barely passes the pin. Double check this measurement and you've found TDC. Remark your vibration damper or simply bend the pointer to the TDC mark for accurate timing.

http://i244.photobucket.com/albums/gg18/barry2952/1%20Mark%20II%20docs/IMG_2555.jpg

[TomPiantanida]

Another way to do it is to turn the crank by hand until it is a few degrees before top dead center, and mark the crank pulley/harmonic balancer. Then insert the TDC center tool and turn it in until it touches the top of the piston. Next, turn the crank backwards by hand until the piston once again contacts the TDC tool. Mark the crank pulley. Measure the distance between the two marks that you made; TDC is half way between them