I think there are errors in the math as well as your formula. You should
not have done the "x5" since the 5 degrees was already accounted for in
the 72 number.

Mark

B.J.R. wrote:
> Hey David,
> Just a side note.
> Going through your equation below, I did my measurements on the crank pulley,
>  62cm = 620 mm/72 = 6.21111x5=43.055/10=4.30cm
> so taking that and marking that distance on the pulley I get A measurement
> But while doing this I found the chewed up timing scale stuck into pulley itself
> And found that the above equation result was way bigger then the actual timing marks spacing
> This morning it occured to me,
> 2 rotations equals one stroke so does that above equation need to be divided by 2?
>
> So I was able to time it temporarily mounting the demolished timing scale
>
> But I thought Id point out the discrepancy for others future use
>
> B
>
> 1) mechanically determine firing-stroke TDC on #1 cylinder, using a
>
> probe into the plug-hole.  For check, the mark on the crank pulley
> should be in about the right place per the picture in Bentley.
>
> 2) Mark that position in the place where the scale should be.
>
> 2a) :-)  Measure or otherwise discover the circumference of the crank
> pulley, then calculate the distance (circumference / 72) represented
> by five degrees.  Assuming the engine turns to the right, mark the
> crank pulley that distance to the left of the TDC mark.  Now time
> using basic timing light, but matching the 5-degree mark to the case mark.
>
>
>
> --
> David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
> '84 Westy "Dutiful Passage," '85 GL "Poor Relation"
>
>
>