I havent read all this, its late, im tired. This is the concise answer that jumps out to me. Think about a driveshaft phasing. Thats a locked phase. Advance curve means isnt a locked phase.

Correct, the rotor/reluctor which are fixed to each other HAVE to move to get the tooth closer to the magnet so it will fire earlier for mech advance but this may convince you without a live eng test tomorrow: I just went out in the kitchen & held a dist upright & held the lower shaft immobile then turned the housing slightly till the magnet was lined up with a tooth and noted where the rotor pointed on the housing perimeter (which'll be the cap terminal location) then I turned the (SB) housing a bit CW which put the tooth a bit CCW from the magnet, then holding everything (lower shaft/housing) still, I grabbed the reluctor & turned it CW against the springs till the tooth lined back up with the magnet which would be when it would fire which is earlier (advanced) & lo and behold now with the tooth lined up with the magnet in this advanced position the rotor (rotor phasing) is in the same position on the housing perimeter/cap terminal location where it was before which is what you guys will see tomorrow when you do it on the car with a drilled cap/timing light like I have seen/done before several times (on eng with drilled cap/timing light) and I am going to do it again just to hold up my end of this threesome bargain. it's all over but the cryin! sleep tight dont let the bedbugs bite & we'll check back in tomorrow evening/later on in the day. RR

wow, look what i started! i should get a share of the booty just for getting all this going!

i looked at my rotor, and there was only one spot of discoloration, all the way on one end. with the cap off and the distributor in the engine, i set the timing at 32 on the damper, firing for cylinder no 1, and then moved the rotor to full mechanical advance. sure enough, the side with the discoloration was not in line with the terminal post.

i removed the distributor and was going to remove the reluctor, and noticed there was no roll pin. the reluctor was fairly tight on the shaft though, but who knows if it moved out of place. i have one of the modified reluctors with multiple slots, and found the one that positioned the reluctor, and so the rotor, a bit more in the direction to bring it closed to the terminal post.

put it back together, fired it up, timed it, but it was raining out, so i didn't get a chance to play with it.

i still have to take the cap and drill a hole and see if it really is where i want it, or if i have to move it again, but i think i'm good to go in that respect. whether the cap needs more ventilation, i'll try that if i still have problems.

(1) No habla Englesh (2) at 32/reluctor held against springs if you then turned the housing so the magnet lined up with the tooth the rotor discoloration location would be lined back up (if you are on the same reluctor roll pin hole). (3) yes you need the roll pin, maybe it dropped down in there. (4) Please do the test with the 1/2" hole in the cap for rotor roll pin selection and for backup for me (uncap the can & see that it does not move as you rev it). if you have a vac pump you can pump up half of the vac can arms' travel and select the roll pin hole that will center the rotor on the cap terminal.

After going to bed and thinking this through, I concede. You are correct. The timing light will only be triggered by the pickup which is effectively locked to the rotor.
Although the rotor is moving forward in relation to the engine, it is not moving from its point of reference, the pickup, unless influenced externally by retards, etc...
Thanks for the edumacation.
signed RED IN THE FACE

As I stated last night.. the rotor will change
.. I dont care if he can see it with the light..
its only gonna move about 8*(16* at the crank)

Trendz, its sounds like we're good. My PP addy is rapidrobert at intergate dot com A $10 gift is fine (I wont accept the 100 you offered as I am just too nice of a guy). I was for sure not looking forward to putting "Trendz Teaches Truth" in my sig! One down one to go. Now Mr P is a very tech savvy sharp guy from his posts I have perused especially on carburetion but he is also stubborn and opinionated (also from his posts that I have perused) & he's gonna take (alot) more convincing, OK Mr P lets cut to the chase & you put on a cap with the 1/2" hole and grab your light & we'll see if the rotor position (phasing) changes when you rev it (can capped of course).

The rotor will change position in relation to
the cap.. your light will still make it look
steady BUT look at it in relation to the cap..
the rotor will have moved

Our bet/my position/our point of contention is: only VA will change RP, the mech adv curve will not change it. Shining the light in there shows that the rotor tip clocking around the arc does not change in relation to the cap which means the RP ain't being altered by the mech curve. The rotor does NOT move, it stays in that same relative position to the cap terminal which is the very definition of RP. Give it some thought & I'm gonna get out & get some work done, we'll get together later this eve. RR

if the rotor doesn't move than the timing can't move either.

seems, the pic that trendz posted earlier of the mech adv assembly shows how it all works. that assembly (which the rotor is affixed to) rotates around to advance the timing. the length of the slots limits how far it can move and the springs limit how fast/easily it can move.
the rotor must move in relation to the cap terminal or else your timing can't move...because the cap is definitely not moving once you tighten it down.

so does the reluctor move or does the rotor move to advance timing??

Jeeesh!! What the hell happened to is thread??? I read some of it, so - let me put it to rest. THE ROTOR MOVES WIH THE ADVANCE. I watched it through the 1/2" hole I drilled next to terminal #1 ( with a timing light ) on my cap. Keep in mind, it's only about a 12 degree movement at the distributor = 12 + 12 at the crank + initial timing of 12 -14 = 36 total. The Mopar distributor as I bought it, was way out of phase ( rotor to cap relationship ). I was able to correct it with the multi slotted reluctor I bought. The 15 degree advance slot put it on the money. So, at full mechanical advance the rotor lines up perfectly with the cap terminal. This is what you want because that is when the engine load is usually the greatest. At idle, the rotor is slightly misaligned with the cap terminal due to the advance thing), but who cares at idle. I was surprised to see it that far off and I would advise anyone that uses this distributor to sacrifice a cap and run the test. I suppose you could re-index the cap to get the same results, but the multi slotted reluctor I purchased worked great to fix this problem. I might add that all caps aren't created equal. I have one cap that shows a solid burn across the entire brass terminal and I have another cap ( from NAPA ( brass terminals and looks identical to the cap that came with the dist. that shows a burn that covers only 1/2 of the brass terminals. As I said some where in this thread, "this distributor was a turd".

I originally posted that only vac adv will change rotor phasing. RP is how close or far away the rotor tip is from the cap terminal when it fires. this is what you see/check with the timing light in the drilled hole in the dist cap. Crizila if your rotor is moving then you have the can hooked up. If you pull the hose and plug it then the rotor tip you see with the timing light will NOT move when you rev it, which is my position that only vac adv and not mech adv will alter RP. We got off on a tangent didn't we! I rarely get into these dogfights (I learned my lesson way back with the other double R) but I made a statement & they said I was mistaken so I had to defend my position! Krautrock, yes of course the rotor/reluctor/shaft all of it is moving but we are speaking of RP only (& what does and does not alter it) and vac adv will swing it thru an arc (a 11 deg can will effect a 11 deg arc that you will see in the hole in the dist cap and a good way to center that arc on the center of the cap terminal is the reluctor with the multiple roll pin holes (drill you own, I did)

Well I gather you did do the test today...
otherwise you would have seen it moves in
relationship to the cap
EDIT
I was gonna run the test today.. I just fired
up my Rampage so I was gonna do the test.. but
I only have 1 dist that will advance and its a
adjustable thats locked out.. I was gonna change
it but I dont have any heavier type springs.. the
ones in it would be full advanced by idle rpm which
is what I use to use in my other engine.. but this
engine is injected and likes the locked out dist so
the computer does the rest.. I'll look a bit more
tomorrow to see if I have a decent dist.. if I do I
will pull the one in the Rampage and video the test..
I was gonna start it with the timing light on it and
mark the back edge of the rotor as seen by the light..
then start increasing the rpm.. the whole time with the
light on it.... wish I hadnt sold my dist machine
it would have been much easier to video on it

At any rate, I have another cap that I want to use ( permanently - reads in bad weather ), so I think I am going to drill it by #1 tower to make sure it index's properly, and then make a clear Plexiglas circle that I can silicone over my viewing hole. Any thoughts on that? When you buy a new cap, drilling it is the only way to know for sure that it is indexed properly. I will put up a pic when I do this. I finally got my SB to run 1/2 decent under load. Part of the problem was the 15 degree off on the index. Other part was I live at 5000 ft above sea level. Stock primary jetting for my 3310 was #72 jets. Ended up with #67's. Time for a nap!!!

P I did not do the test when I posted above as I just popped in for a bite to eat but I went right back out & did it first thing and with the hose off/capped I revved it & no phasing change (& I did twist the rotor to make sure I had advance) then I plugged back in the can & it moved it & I revved it & no further movement ex for what the can initially provided when I plugged it in. I repeated several times just to be 100% on this even tho I have done it many times before.

ok so what moves to make the mechanical advance work?

If it didnt move your mech advance was already
in (advanced)... it will move if the mech is
still retarted.. this is FACT
EDIT
By the way.. I bought my dist machine out of
the dist lab at Chrysler.. where I worked for
1 year before I moved to the fuel lab.. I did
this test a lot and magically it moved each time
unless it was already advanced.. but the nice
thing about using a dist machine is you can start
out at zero rpm and work up to 4000 (dist rpm)to
see the total advancement on the mech.. then apply
the vac for total

it seems logical that since the rotor to reluctor clocking is fixed (unless you alter it with the reluctor with the multiple holes) then when the reluctor teeth are moved closer to the magnet (being advanced by the springs) so it will fire earlier then how could that not move the rotor (which is locked to the reluctor) the same # of degrees closer or away (as the case may be) from the cap terminal (rotor phasing). I would suggest wrap a shop towell around the dist lower shaft to protect it then clamp it reasonably snug in your vise straight up vertical then go back to one of my earlier posts & work with that procedure & you'll see. its like in a SB CW rotation dist, the springs/slots/weights let the reluctor rotate CW so a tooth reaches the magnet maybe 10 deg sooner (advanced) AND the rotor (which moves with it) is also rotated 10 deg CW so the rotor ends up exactly in the same position relative to the cap (same phasing). EDIT Krautrock this was for you. P, I thought for a second I had you convinced! When can you do the test (no need for a video). I did my part. PS Trendz manned up & paid the bet, I'm waiting on you

Believe me, I had a hard time with this also. My own argument is what convinced me. Look at the picture of the distributor. The rotor and reluctor are locked together. This by itself means that the trigger and rotor will always be "in sync" with each other.(as long as there are no external retards)
Since they are mechanically locked together, and the pickup coil and distributor housing are basically fixed in place.(assuming no vacuum advance moving the plate) Then the only thing that can happen is they will all stay in sync with each other.
Now what does happen, is everything below the plate moves to a retarded position. (When viewed from the ignition pickup's point of reference)
What is important is the point of reference.

Yes they are in sync with each other... but as the weights
move outthe advance starts.. this is the part that if
you have the engine off you can twist the rotor.. thats
the mech advance.. now when the engine is running it will
always LOOK in sync.. but put a pencil line on the cap
and start advancing it.. what occurs.. the rotor moves
BUT still looks in sync