....... - but apparently the engineers back in the day knew what they were doing. So does it REALLY matter WHY?
I'm going to make the following comments, and then I'll move on....
Yes it matters, at least to me....from both an engineering as well as a historical perspective. For the sake of completeness of the CRG report, I would hope that it matters as well - if nothing more than to add a footnote in the report noting that 32 deg out of phasing of the yokes is well outside of normative engineering practice and at this time the reason(s) are not known.
I have been pondering why this happened for almost 30 years; since July 1992 when I had the driveshaft in my '69RS corrected to in phase yokes. I would simply ask that you take 2-1/2 minutes to watch the following video from Spicer:
https://www.youtube.com/watch?app=desktop&v=Idk3BVDVHq4The demonstrator they use in the video, both visually as well as audibly, shows the effect of:
1) not maintaining the same operating output angle between driveshaft ends (first two minutes) and
2) what happens when you change the yokes from in phase to out of phase.
I don't doubt that the engineers knew what they were doing.......one possibility is that they had discovered a high rpm driveshaft resonance problem. An inexpensive fix for a driveshaft resonance issue could have been to offset the yokes which would effectively stiffen the driveshaft and shift a resonance frequency(ies).
They could have accomplished the same thing by changing the diameter/thickness of the driveshaft tube material, but that would probably be a more expensive route to take.
Of course the downside of knowingly offsetting the yokes would be that they were fully aware that they would be introducing a 2X vibration into the driveshaft along with both inertial and torsional forces and resulting vibration(s). One could argue that as long as the driveline lasted the length of a race or for 5 years for the general public.....
Richard
