I think everyone is assuming mechanical advance is doing what you see in the video. Some of it could be the multi spark to single spark crossover at ~3000 rpm, and whatever timing curve they have programmed into their box.

MSD's own rotor phasing instructions make no reference to mechanical advance at all, only vacuum changing the rotor phasing.

http://08961cd535df487cd1c1-bda68e188d86291aa366f725b37d442b.r87.cf1.rackcdn.com/84211_tb.pdf

You can see that the rotor MOVED.. its a mech
advance dist only... multi spark has nothing
to do with making the rotor move

The timing curve programmed in the box would change it, and they are specifically talking about timing being retarded for nitrous use in the video. You both are assuming the mechanical advance is doing it, but there is no evidence to prove or disprove that.

where is the video, I cant find it

Can you see the rotor position has changed...
you tell me how electricity will change the
physical position of the rotor.. that isnt a
optical illusion
EDIT
that video is talking about phasing the rotor
and talks about what COULD happen if the rotor
doesnt line up... and he talks of retarding the
timing in the case f running spray... the title
of the vid was rotor phasing

Mr P I see a gaggle of em on youtube, which one is it?

In Trendz post on one of the first few pages..
I just seen you asked it a couple of post back
sorry didnt see it

thanks bro, let me scroll back & find it. EDIT Found it & he says that if you change timing you need to check/possibly reset RP and he said something about a possible 25 deg arc (RP) change. I looked close but could not see a vac can but the movement of the rotor tells me it is operational. I am going to call him tomorrow (got free LD on my new phone so might as well put it to use). I'll post what he says. I ain't up on the start/retard stuff he mentioned but I'm looking forward to talking with him (Joe Pando)

There isnt any vac pot on it.. I have the
same dist on my W-9.. its their race unit
EDIT
it has a adjustable mech advance plate.. either
use advance or lock it out

The initial advance is set by hand. The rotor phase is set at that baseline. If you twist the dizzy, you are changing the rotor phase. Since we need a spark event sooner as rpm rises, and we cant reach out there and give another twist, the mechanical inside does the job.

Why else would mech advance be there? No way something that elaborate was conceieved and installed in a trillion cars otherwise. The vac advance does the same job, but needed a third way of changing rotor phase based on load.

It doesnt follow the pickup or ecu or anything else is determining when to switch on to give a spark event sooner. That is the only way you could get a spark sooner for the mech portion of the program, if the idea is the rotor phase isnt alerted by the mech advance. Im talking strictly about stock parts here, no multispark, crank triggers, fixed distributors, etc.

From your post, it seems you think rotor phase has an effect on ignition timing. It doesn't, unless you are so far off that it can cross to the next terminal.
The timing is triggered by the pick up.
The pick up is stationary when not in vacuum advance.
The reluctor is fixed to the rotor.
Nothing in the upper half of the distributor changes without vacuum.
Timing change at the ENGINE is caused by the distributor shaft being delayed by the mechanical advance. That is all there is to it.

Your second sentence is not correct. Moving the rotor in relationship to the reluctor ( phasing ) will have an effect on ignition timing. I just did this. Installed a different reluctor ( 15 degrees advanced ) in order to get the rotor to line up with the cap terminals. When I checked the timing, it was advanced 15 degrees. Had to retard the dist. to get the mechanical timing back where it belongs.

All of those sentences are correct. You may be interpreting it wrong.
Moving the reluctor has an effect on timing, but moving the rotor does not.

Yes, it does have an effect. Twist a distributor and tell me if changing where the rotor is in relation to the terminal has an effect.

The rotor's job is to direct the "already timed" spark from the coil to the correct cylinder. It has no inflence on timing.

" interpreting it wrong" is a big part of this thread.

Grab a dist & do my procedure. it'll take 3 minutes (if that). you'll see the "magic". EDIT I just got off of the phone with MSD & he said that in Joes video their retard (nitrous app I'm assuming) box that electronically delays the timing to retard it, the timing does change RP (seen in the pic) & he went on to say that with regular mech adv the RP does not change

X2. If moving the reluctor position makes a difference, moving the shaft it is mounted to has to also make a difference.

This needs to go in the archives next to the pinion angle and 8 and 3/4 posts 😊

That video shows the advancement of the rotor as
the mech advance comes into play.. plane and simple
do you agree