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Old 11-10-2012, 06:27 PM
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Originally Posted by Stubbs82 View Post
when i brought up #1 TDC and adjusted the cam and sprocket so that it was at 6 and the crank was at 12, did i cause the timing to be off by not setting the cam and crank at 6 & 12 with the #6 TDC? I wouldnt think it would run at all if that was to happen.
When you brought #1 to TDC, you also brought #6 to TDC. They are companion cylinders, except that they are 360 degrees apart. Remember, there are 720 degrees in a complete cycle, on a 4-cycle motor, so if you put the cam sprocket at 6PM and the crank sprocket at 12PM, the motor is ready to fire #6. The cam lobes for #6 will be on the backside of the lobe, more or less on the base circle, which means both valves are closed, ready to fire. Meanwhile, #1 cylinder is 360 crankshaft degrees away from what #6 is doing, even though the piston is at TDC just like #6. The difference is that #1 is at TDC overlap, where both valves are open.

Let me explain it again. Install the crank gear with the dot at 12PM, then install the cam gear with the dot at 6PM. Pay no attention to where any of the pistons are in their respective bores. Bring the dots together where a straight edge would run between the centerline of the crankshaft, up through the crankshaft dot, up through the camshaft dot and on through the centerline of the camshaft. When you have this part of the motor installed with chain and the dots lined up, rotate the crankshaft one complete turn clockwise so that the camshaft dot is at 12PM and the crankshaft dot is at 12PM. Now, the motor is ready to install the distributor and run the wiring because both valves are closed on #1 and #6 is on overlap.
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