Editing How to make a timing tape

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 the tab is actually "0" degrees (TDC)
 
'''OR-'''

'''2.''' You find TDC by using a piston stop and fabricate 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.

Once TDC has been established, the rest goes like this:

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.

Once the circumference is known, 1/10 (10%) of this figure represents 36 degrees. Half of that is 18 degrees, half again is 9 degrees, etc. It doesn't matter what units you use- metric, inch, or nanoparsec's.

When marking your home-made tape, starting from "0", BTDC will be to the right, ATDC to the left of "0".

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. 

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.

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.