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| Joined: | 09-17-2007 |
| Location: | San Francisco, California USA |
| Posts: | 221 |
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My process has always been:
1) Line up TDC on the crank to as close to the mark as possible (hopefully this is an accurate TDC mark)
2) Mark the distributor pulley at some point (I usually line it up with the bolt that holds it onto the bracket) just to make sure you will return to a ballpark timing. I always use some red nail polish to mark it.
3) De-tension the belts (replace the belt if needed) and align the pulleys to the correct timing marks
4) The belt slack must be controlled well, it needs to be as tight as possible across the distributor pulley to the two cam pulleys, and then as tight as you can get it (just making sure there is some tension across the teeth of the belt) going down to the crank pulley. If you do not pay attention to this slack, when you tighten the belt things are going to slip out of alignment as the belt is tensioned.
5) Hold the belt across the cam pulleys and down to the crank pulley as you add tension, slowly and in a linear way. Try and make sure the distributor returns to a ballpark area of it's mark, this is difficult to do.
6) The slack should only come out between the crank pulley and the tensioner, minimizing any slip or teeth jumping at any other point.
7) Tension the belt by taking the reading with the Burroughs between the distributor pulley and the intake cam pulley
8) Rotate the engine a few times manually (always clockwise) and verify that the timing marks always return to their correct positions. This is where you loose faith- because a single jump of a tooth or a bit of slack in the wrong place can throw you out by 5-10 degrees. If it's not quite right, just repeat the entire process again. It takes some time to master.
9) Check and adjust the ignition timing. It's been my experience its very hard to get the dizzy back to the original position, and it always requires some adjustment.
NEVER rotate the crank and cam pulleys independently of each other by more than a few degrees. This is an interference engine and valves will collide with pistons guaranteed. Always keep things within a few degrees, and only make very small adjustments to the cam pulleys for timing corrections and always keep that crank on it's TDC mark. If you feel any resistance at any time, back off and rethink what's going on.
Also it's always helpful for me to remember that it takes TWO rotations of the crank, 720 degrees, to return cams to their correct TDC relative markings, not one rotation. So in other words, you are always going to have to rotate the engine at the crank twice to check if the timing marks all line up.