Originally Posted by billc
I've recently compared the UR timing marks to the OEM crank. Because of the difference in diameter and the thickness of the pulleys, I concluded it would be real hard to transfer timing marks with any accuracy.
Keep in mind that once you put the smaller crank pulley on, the distance between your timing pointer and the crank increases enough to introduce error as you move your head around while siting the timing marks with the timing light. This factor only makes it more challenging to accurately set the timing after the pulley install.
What to do? Set the base timing before the install. Mark the distributor and housing at 15* and 19*. Use these marks for future timing adjustment -- they probably will be more accurate than any marks you can put on the smaller pulley.
If you want a backup, transfer the marks to the new pulley. Then check your base timing again and see if the marks are accurate. Make notes about how the marks calibrate and how to position your head for consistency.
I've recently compared the UR timing marks to the OEM crank. Because of the difference in diameter and the thickness of the pulleys, I concluded it would be real hard to transfer timing marks with any accuracy.
Keep in mind that once you put the smaller crank pulley on, the distance between your timing pointer and the crank increases enough to introduce error as you move your head around while siting the timing marks with the timing light. This factor only makes it more challenging to accurately set the timing after the pulley install.
What to do? Set the base timing before the install. Mark the distributor and housing at 15* and 19*. Use these marks for future timing adjustment -- they probably will be more accurate than any marks you can put on the smaller pulley.
If you want a backup, transfer the marks to the new pulley. Then check your base timing again and see if the marks are accurate. Make notes about how the marks calibrate and how to position your head for consistency.
IF these come un marked i will install all 3 pulleys minus the crank pully........do all my tuning with the stock crank pulley. then simply swap pulleys once i feel everything is as i like.