Rabid Robert If you are stating the rotor phase doesn't change in relationship to the cap during mechanical advance, youd be wrong.

Further there are 2'Two' different movements going on to advance the timing at the distributer.

The first is the mechanical advance it rotates the rotor and trigger/points cam forward to cause the spark sooner. This distance is about 3/16s of a inch. Since the rotors tip is a 1/4 inch all is good.

Two now the vacuum advance, the rotor cant turn anymore as you stated, the vacuum can now rotates the pickup/points base towards the can further increasing timing Without further rotating the rotor. That's how you get get the combined amount advance degrees without rotating the rotor to far out of reach of the Caps pickup terminal. That's about a 1/4 of inch in with also.

I think you need to put that distributer back in the vise and do some more studying.

Oh, and some refunds are going to be due.

Or Maybe Im having a Hellen Keller moment, but I don't think so.

Another fish on the hook!
Don't take the bait!

The pickup is mounted to a base plate. The trigger star wheel is fixed with the rotor. The mechanical advance Rotates the rotor and its Trigger wheel in reference to the stationary pickup, thus altering the timing.

Then the vacuum advance can rotates the pick up plate in relationship to the rotor and its trigger wheel further advancing timing.


Maybe you need another nights sleep to further think this through.


If Im wrong, I only have two posts showing it. Boy , if Roberts wrong, hes got like 4 pages of Wrong.

Alright. Let me do something funny here...
RUN down the hallway of your house into a room.
Turn on the light switch. Did the light come on instantly?
Now, WALK down the hallway. Turn on the light. Did the light still come on instantly, or did it come on before you flipped the switch? Or a little after the switch?
Really, what happened before you flipped the switch is irrelevant to the light. The mechanical advance happens before the pick up.
The pick up coil IS the switch. It will "turn on the light" at the same distributor position every time.
Do we all agree that the rotor is locked to the reluctor? YES
Is the pick up "fixed" in place with no vacuum advance? YES
Then what you really need to accept(like me) that it will always trigger in the same distributor position.

Sure... IF you dont use a reference mark on
the cap and you are using a timing light...
the light will fire at the same time as the
rotor all the time.. but then look at the reference
mark on the cap... whats the use of having the slots
and springs with a movable timing plate.. I guess
they could have made it solid

The rotor Is locked to the reluctor/trigger. YES
But its relationship to its pickup Does Change with the mechanical advance.

The pickup is Fixed on a plate, But that [plate Is moved by the Vacuum advance. So No on that second statement. That plate with the pickup is indeed moved in relationship to the reluctor.

Lights are being turned on at different timing events for sure, as we see.

Further Robert made a mistake with his numbers. Hes stacking the mechanical advance with the vacuum advance to show the Rotor rotates that combined amount of degrees away from the caps pickup terminal. This says, hes missing it.

That's incorrect the Rotor and reluctor only rotates away from the cap terminal and the pickup by the Mechanical rotational advance. Witch would be 10 degrees at the cap or 20 degrees at the crank on a 20 degree mechanical advance distributer. The Vacuum advance only moves the pickup plate in the opposate direction of the rotors movement not Effecting the rotors position to the cap but indeed Further effecting the relationship between the pickup and the reluctor

The "advance" we speak of is using the engine as a point of reference.
The problem is, we are now using the distributor as a point of reference. So if it's true that the engine advances the distributor, then, isn't it also true that the distributor retards the engine?
The link between the upper distributor and the engine is the mechanical advance. This link is what changes the relationship between the engine and upper distributor. The upper distributor stays constant with itself, but not the engine.

Centrifugal force is doing the advancing based on
weights at rpm

Previous posts and even my quote here take the vacuum advance out of the equation by disabling it. So lets change your answer to YES.
We all agree that the vacuum advance will change rotor phasing.
Please explain how the rotor can be in a different position if the rotor is locked to the reluctor, and the trigger happens when that reluctor passes a fixed place pickup.

[quote=TRENDZ]Alright
The pick up coil IS the switch. It will "turn on the light" at the same distributor position every time.


This is the key right here. Got to think about this some more.

Can see where when the Two meet up reluctor/pickup that they will energize at the same spot in relationship to one another, everytime, Like Dead inline.

I can agree with that. Dead inline, bang we have fire at the Same spot. Say at 0 degrees on a 360 degree circle of the cap.

Now lets put the distributer at 350 degrees, or 10 degrees before the next alignment. Add 10 degrees for the mechanical advance rotation of the rotor and reluctor and we have another perfect alignment for a energize. Sure the reluctor and pickup are now energizing at the same exact alignment , but guess what. The rotor is now 10 degrees rotational different from the cap.

The rotor is indeed 10 degrees advanced from where it was before compared to the cap , but yet the relctor/pickup alignment is the same.

I can see why this is hard to get the head around.

So

Yeah I'm old and I'm sure I forgot plenty over
the years... but WHY have a plate that MOVES..
sure could have been a cost savings to dump the
weights and springs along with a separate top
timing plate... you can twist the rotor.. correct..
WHY.. to have mech advance... its a relationship to
the rotor and cap.. yes it still fires at the same
point in relationship of the reluctor and the rotor
when using the timing light..but NOT in relationship
to the cap... put a reference mark on the cap
EDIT
why is it that when the mech timing comes in
it changes the crank timing... nothing moved

can someone define what rotor phasing is?
and see the quote from RR that i quoted in this quote (so meta)

I will definitely mark the cap as you suggest. I think this video may be a blockbuster!
When the mechanical timing comes in, it is delaying the link between the upper distributor, and the engine.

See my link to youtube in earlier post to define rotor phasing.

The point when the reluctor and rotor tip and
the cap are working together.. if you notice
the reluctor wheel has 2 roll pin slots.. they
are not 180* from each other.. in most cases you
can turn the wheel 180* and help the phasing..
in a Chrysler dist they put those 2 slots in it
to cover up any mis match in the tolerance machining
and one or the other slot would correct it

Now lets put the distributer at 350 degrees, or 10 degrees before the next alignment. Add 10 degrees for the mechanical advance rotation of the rotor and reluctor and we have another perfect alignment for a energize. Sure the reluctor and pickup are now energizing at the same exact alignment , but guess what. The rotor is now 10 degrees rotational different from the cap.

The rotor is indeed 10 degrees advanced from where it was before compared to the cap , but yet the relctor/pickup alignment is the same.

I can see why this is hard to get the head around.

So [/quote]
This is where you go wrong. If the reluctor is 10 degrees before the alignment, and the shaft is spinning fast enough to already have the advance working, that means in 10 more (shaft already advanced) degrees it will fire in the same spot as it does without the shaft advanced. The advance happens before the reluctor. The rotor will end up at the same spot as the trigger point every time.

Yeah I'm starting to get a bit Rapid, in fact I might have to just get a job (it'd be easier). Sport440 do you want in, ($10 entry fee). OK My original statement was that only vac adv and not mechanical adv changes RP & RP is how close the rotor tip is to a cap terminal when it fires & we check this with a timing light in a 1/2" drilled hole in the cap. I've observed this a dozen times when working on peoples' dists and the other day I went out & did it again cuz me & mr P body and Trendz were all three supposed to do it. Trendz seen the light (in his head) without popping the hood. I'm waiting on Mr P body. If YOU do the test (vac capped) & it moves then yes refunds/apologies are definitely due & I am a man of my word. DO the test & report back. Do the test & report back. PLEASE! drill the hole/cap the can/hookup light/rev it up/see what the rotor (RP) does/holler back. does it move or does it stay still, that the only Q at hand. Sport440 get in on this before you do the test. (I missed my steak today)

Like I said I am sending out a dist to Trendz
(Rick) most likely tomorrow and he is gonna
do the test on his dist machine and video it..
with a reference mark on the cap to show the
change with rpm... I would have sent it out
today but I never made it into town

Correct, the reluctor tooth reaches the magnet sooner cuz the weights/springs/slots are rotating the reluctor forward (in relation to the dist lower shaft) (CW in a SB) so it reaches the magnet sooner and when it does (sooner) the rotor tip (RP) will be in the same position. hold it in your hand or clamp it in a vise & you'll see (I just did it again in the kitchen). It IS a strange deal cuz it dont make sense, take 5 minutes and you'll see. EDIT Mr P I just saw your last post, we're good, I'll hang loose bro. RR. MORE EDIT, to me its kind of like an illusion or magic trick that does not make sense till you grab a dist & try it (I never woulda figured out the how and why of it till this came up but that's a good thing).

If the reluctor and the rotor are mounted to the same plate/shaft, the one advanced by the weights/springs, how can the rotor position not change in relation to the cap when the mechanical advance kicks in?

Im currently hundreds of miles from home with nothing to go pull out first hand. Maybe i can find a schematic online someplace.