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Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327717
05/26/09 12:19 PM
05/26/09 12:19 PM

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If you are sure the advance plate is not moving around, it seems to me at least two possibilites are:

A triggering problem in the light--not likely, but not unheard of. Is this a delay light?


Worn/ loose shaft bushings allowing the shaft to move in relation to the pickup. With the Mopar aluminum housings, this used to be a huge problem, and is why I eventually ended up with a Hemi dual point which has a ball top bearing (tach drive)

Re: rotor phasing experiment. whats this mean? #327718
05/26/09 12:51 PM
05/26/09 12:51 PM
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Quote:

If you are sure the advance plate is not moving around, it seems to me at least two possibilites are:

A triggering problem in the light--not likely, but not unheard of. Is this a delay light?


Worn/ loose shaft bushings allowing the shaft to move in relation to the pickup. With the Mopar aluminum housings, this used to be a huge problem, and is why I eventually ended up with a Hemi dual point which has a ball top bearing (tach drive)




those are the only two i can come up with too. i check the plate to see if it could move easy (the one the pick up mount to) and its pretty tight. doesnt want to move back and forth BUT i can tilt it and that would change the gap and most likely the timing of the spark

Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327719
05/26/09 01:23 PM
05/26/09 01:23 PM
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At lower speeds you can have bounce especially at idle. This is normally the combination of the chain slop and the mechanical advance bouncing because of it. There is not enough constant rotation at idle on the cam and it can actually want to turn the cam the other direction for a split second during idling. On some cars with big springs and low vaccuum this will happen several times a second at idle. On many cars you will see this happen for a split second as you give it throttle and when it initially maintains an RPM. If you check the timing with the timing light this will coincide with it, and although people will argue this, this is not necessarily a problem unless it is extremely bad and happens at mid to high RPM. It can be impossible to remove this bounce completely and converting to a timing belt with a tensioner can help.


Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: rotor phasing experiment. whats this mean? [Re: HealthServices] #327720
05/26/09 01:56 PM
05/26/09 01:56 PM
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Quote:

At lower speeds you can have bounce especially at idle. This is normally the combination of the chain slop and the mechanical advance bouncing because of it. There is not enough constant rotation at idle on the cam and it can actually want to turn the cam the other direction for a split second during idling. On some cars with big springs and low vaccuum this will happen several times a second at idle. On many cars you will see this happen for a split second as you give it throttle and when it initially maintains an RPM. If you check the timing with the timing light this will coincide with it, and although people will argue this, this is not necessarily a problem unless it is extremely bad and happens at mid to high RPM. It can be impossible to remove this bounce completely and converting to a timing belt with a tensioner can help.




but i should NONE that looking at what Im looking at.

the coil fires when the reluctor spline passes by it, send the bolt thru the top of the rotr, out to its tip, over too the cap terminal and out the plug wire. the timing light fires off when the bolt goes out the wire to the plug.

the rotor and reluctor never change relativce to each other. the pick up never changes cause theres no vacuum advance.

I AM seeing the tip of the rotor move ONLY when i rev it quickly and when I let go and it drops back to idle. rotor is only displaced from the terminal during that split second of Revving it, then it moves back to the terminal if I hold it at high rpm or at idle. its only during the quick rev and de-rev that it moves off the terminal

Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327721
05/26/09 02:14 PM
05/26/09 02:14 PM
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You have mechanical advance right?

Check this with your timing light at the timing mark (at the balancer) it will do something similar.


Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: rotor phasing experiment. whats this mean? [Re: HealthServices] #327722
05/26/09 02:49 PM
05/26/09 02:49 PM
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Try this.
  • Turn engine over until you see the rotor move.
  • mark the balancer at this point.
  • Now turn the balancer the other way until you just see the rotor move the other way. This is ~ how much slop you have to the distributor.
This is 'A' and ideally the amount slop you will see when you first give it gas, release the throttle, and at idle

Now if you have mechanical advance with no vacuum. If you have vacuum advance just remove and plug the hose.
  • check the timing at idle.
  • Check it again at its highest point.
Subtract the two values and you have your mechanical advance. This is 'B'

Worst case scenario the amount of timing bounce you will have is A and B together. This is if you had a weak spring in the distributor. It will never get that bad because the spring will not allow that much bounce.


The amount of slop in 'A' will cause a certain amount of bounce or timing slop. But the amount of 'A' in combination with 'B' will cause a larger amount of bounce.

Either way this slight bounce is nothing to be concerned with because you are just returning to idle or you are just giving it gas, taking the slack out of 'A'. Unless of course you have a supercharged blown funny car running nitro methane, in which case an errant spark can it can potentially blow the supercharger or the head off.


Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: rotor phasing experiment. whats this mean? [Re: HealthServices] #327723
05/26/09 04:15 PM
05/26/09 04:15 PM
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i know i have slop. but the check i am doing wont see that. the light will fire when the reluctor passes- WHENEVER the reluctor passes. The rotor's position inside the cap gets illuminated by the timing light.

and slop in the distributor wont change the relationship of the rotor to the reluctor except for slop in the rotor to shaft or if there was any slop in the reluctor to the shaft (but its tight there).

and the amount of play i have in the rotor to the shaft is miniscule. Im seeing maybe .001-.003" play in the rotor to shaft but I am seeing 1/2" to 5/8" of jump in the position of the rotor when I shine the light on it and rev it

Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327724
05/26/09 04:20 PM
05/26/09 04:20 PM
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If you have mechanical advance this is what you are seeing.


Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327725
05/26/09 04:23 PM
05/26/09 04:23 PM
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Quote:

i know i have slop. but the check i am doing wont see that. the light will fire when the reluctor passes- WHENEVER the reluctor passes. The rotor's position inside the cap gets illuminated by the timing light.

and slop in the distributor wont change the relationship of the rotor to the reluctor except for slop in the rotor to shaft or if there was any slop in the reluctor to the shaft (but its tight there).




And the rotor in relationship to the reluctor will change when you have mechanical advance. The rotor will advance as rpms increase, but this advance is thru the the use of two weights and two springs.




and the amount of play i have in the rotor to the shaft is miniscule. Im seeing maybe .001-.003" play in the rotor to shaft but I am seeing 1/2" to 5/8" of jump in the position of the rotor when I shine the light on it and rev it




Correct basically there is no way you can see any of this movement with a just a timing light.

Re: rotor phasing experiment. whats this mean? [Re: HealthServices] #327726
05/26/09 04:28 PM
05/26/09 04:28 PM
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Quote:


And the rotor in relationship to the reluctor will change when you have mechanical advance.






i disagree. both the reluctor and the rotor mount solidly to the same shaft. they mount to this (see pic). When one moves, the other moves right with it. As the weights fly out and move the reluctor, the rotor tip changes with it.

Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327727
05/26/09 04:29 PM
05/26/09 04:29 PM
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If the rotor and reluctor is rigid (do not change in relation to each other) no you should not have a change.


Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: rotor phasing experiment. whats this mean? [Re: HealthServices] #327728
05/26/09 04:30 PM
05/26/09 04:30 PM
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Quote:

Why is there a slot?




the slot is so the reluctor AND rotor and move wrt to cam shaft

Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327729
05/26/09 04:32 PM
05/26/09 04:32 PM
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everything I am viewing is from this plate up. i wont see any changes in the timing chain, cam drive, distrib drive.

all i can see is when the spark comes out the wire and where the rotor tip is

Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327730
05/26/09 04:44 PM
05/26/09 04:44 PM
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You are right I was trying to apply the timing error or delay that you see at the timing mark and balancer to the phasing of the distributor. This would not apply to the distributor phasing itself.


Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: rotor phasing experiment. whats this mean? [Re: aarcuda] #327731
05/26/09 05:19 PM
05/26/09 05:19 PM
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Quote:

Quote:


And the rotor in relationship to the reluctor will change when you have mechanical advance.






i disagree. both the reluctor and the rotor mount solidly to the same shaft. they mount to this (see pic). When one moves, the other moves right with it. As the weights fly out and move the reluctor, the rotor tip changes with it.




I agree, you are correct, phasing is the relationship between the rotor and the reluctor wheel - it has NOTHING to do with anything else...

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