How to make a timing tape

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(New page: Making a semi-permanent timing tape is very easy, and removes any doubt as to where the timing marks are or were supposed to be- provided that: '''1.''' You know (or verify) what line on ...)
 
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Making a semi-permanent timing tape is very easy, and removes any doubt as to where the timing marks are or were supposed to be- provided that:
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==Overview==
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Making a semi-permanent timing tape is very easy. It replaces the need for a "dial back" timing light and removes any doubt as to where the timing marks are correct or not.
  
'''1.''' You know (or verify) what line on the tab is actually "0" degrees (TDC)
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==Procedure==
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'''OR-'''
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'''2.''' You find TDC by using a piston stop and fashion a timing "tab" (often a stiff piece of wire secured behind a convenient bolt) that aligns with the line on the damper to represent "0" or TDC.
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===Find TDC===
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You need to know (or verify) that the TDC or "0" degree line on the damper or balancer (henceforth to be called a "damper") and the timing tab or mark actually correctly represents "0" degrees (TDC). On the SBC for example, there are three commonly encountered timing tab/damper lines that can be mismatched, causing an incorrect reading. More on this at [http://www.crankshaftcoalition.com/wiki/Timing_tabs_and_damper_TDC_lines_SBC Timing tabs and damper lines SBC].
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One method to find TDC is by using a piston stop and fabricate a timing "tab" (often a stiff piece of wire secured behind a convenient bolt head) that aligns with the line on the damper to represent "0" or TDC. Help with this can be found at [http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center Determining top dead center].
  
Once TDC is established, the rest goes like this:
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===Once TDC has been established, the rest goes like this:===
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*Using either a string, ruler or a seamstress' cloth tape measure, measure the circumference of the damper. If you only have a straight ruler, measure the diameter and multiply by 3.1416 (pi) to get the circumference.
  
Using either a string, ruler or a seamstress' cloth tape measure, measure the circumference of the damper. If you only have a straight ruler, measure the diameter and multiply by 3.1416 (pi) to get the circumference.
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*Once the circumference is known, 1/10 (10%) of this figure represents 36º. Half of that is 18º, half again is 9º, etc. It doesn't matter what units are used to measure the circumference- metric, inch, or nanoparsecs.
  
Once the circumference is known, 1/10 of this figure represents 36 degrees. Half of that is 16*, half again is 8*, etc. Doesn't matter what units you use- metric, inch, or nanoparsec's.
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*If you want to use the metric system, multiply the circumference by 25.4 to convert to millimeters. Divide this by 360 and you'll get the measurement in millimeters that equal one degree.
  
When marking your home-made tape, starting from "0", BTDC will be to the right, ATDC to the left of "0".
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*Careful measurement and marking of the degrees in this fashion on a length of masking tape can then be applied to the damper, aligning TDC or "0" on the tape to the line on the balancer, with the degrees BTDC to the '''right''' of this mark.  
  
Careful measurement and marking of the degrees in this fashion on a length of masking tape can then be applied to the damper, aligning "0" on the tape to the line on the balancer, with the degrees BTDC to the right of this mark.  
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*You can also measure the length between the timing tab marks and transfer them onto tape, i.e. if there's 3/4 of an inch (0.750") representing 10º on the tab, two marks 3/4 of an inch (0.750") apart on your tape will also be 10º. This will work- provided that the timing tab is correct for the application and not for a different diameter damper.
  
If you are going to invest in a timing light, you might consider an inductive light with an "advance" feature. This allows you to read the timing from just the "0" point, the timing light will then adjust itself to show whatever amount of advance you want, or read the advance without regard for a timing tabs marks, except for an accurate "0" mark.
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===90 degree lines===
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It's a good idea to mark the tape at 90 degree increments starting from TDC. These 90 degree lines can be used when adjusting valves, for example.
  
They cost more than a standard light, but if you plan on tuning engines beyond the basics, it will pay for itself in the long run, IMHO.
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==Correct orientation of timing tape==
  
This sounds more complicated than it really is.
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[[File:Timing tape on dampr.jpg]]
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<br style="clear:both"/>
  
Good luck.
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==Resources==
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*[http://www.crankshaftcoalition.com/wiki/Timing_tabs_and_damper_TDC_lines_SBC Timing tabs and damper lines SBC]
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*[http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center Determining top dead center]
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*[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjust valves]
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*[[Estimating timing chain wear]]
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[[Category:Engine]]
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[[Category:Adjust valves]]
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[[Category:Good articles]]
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[[Category:Ignition]]

Latest revision as of 03:04, 17 March 2013

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