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Re: Distributor phasing is a good idea
[Re: CJK440]
#312415
05/11/09 12:47 PM
05/11/09 12:47 PM
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Joined: Mar 2003
Posts: 15,493
the boonies
aarcuda
I Live Here
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I Live Here
Joined: Mar 2003
Posts: 15,493
the boonies
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Quote:
Quote:
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Alignment can be also be done on the bench using an old cap with holes drilled in it. Line up the reluctor with the pickup and look thru the spark plug wire hole to see if the alignment is correct
Or align rotor with spark plug hole, remove cap and check reluctor to pick up alignment
The vac adv plays an important part in where the "zero" position of the pickup ends up. Many times shimming the vac adv away from the housing quickly corrects any offset. You can also shorten the length of the arm on the vac adv as well if you are creative enough. Typically you will need to space the canister away from the dist body or shorten the arm length to correct any misalignments.
Again I will emphasize how much better any car runs with a phased distributor.
The pic shows the typical misalignment
let me ask- this picture shows a misalignment at idle. but, when the distributor starts advancing, the pickup will move counterclockwise and brign the misalignment back into alignment, won't it? so the net effect would be proper rotor phasing at higher rpm where its more important.
Once the rotor/terminal & reluctor tooth/pickup is phased it is not affected by mechanical or initial changes. The relationship between the relutctor and rotor is fixed and the position of the pickup to the terminal is fixed also. Only when the vacuum advance comes in will it go out of whack because the pickup now moved in relation to the cap terminal.
If your not running vac advance just shoot for dead on but with vacuum advance perhaps you want to adjust it so that the rotor is equidistant from the terminal a zero vacuum to max advance????
i dont believe thats true. i believe mechanical advance as well as the initial timing will change the orientation pickup /cap terminal to the rotor/reluctor spline
the relationship of the rotor tip and star wheel is fixed to the distrib shaft and is driven by the cam (but the relationship can be adjusted as stated above).
The cap terminal is fixed to the body of the distrib housing and will be moved back and forth as the housing is twisted CW or CCW.
When the housing is twisted CW or CCW, the pickup moved forward or aft of the reluctor. thats how mech timing is adjusted. Move housing so the pickup moved toward the reluctor spline and the coil fires off earlier thereby advancing it. move it away, the timing is retarded.
When the coil fires it sends the pulse down to the rotor to arc out to a plug terminal. it WILL JUMP A GAP here. the question is how much.
as the centrifigal advance kicks in, the rotor and the reluctor move so that the reluctor spline moves towards the pickup thereby advancing it
Now, i would imagine the width of the conductor on the tip of the rotor is such that one corner of it aligns with the front edge of the 1/4 wide contact on the cap and as the engine advances, the rotor contact swings through the terminal contact.
point is, the mech and the vac advance changes the relationship of the reluctor spline to the pickup. since the reluctor spline is tied to the rotor it will move in relation to the housing annd the cap terminal is tied to the housing.
Unless the setup was so far out of whack that the rotor tip was so far infront of the cap terminal or already behind it such that the spark couldnt jump (or would jump to the next terminal), you'd never see a problem.
Im going to play with my distributor and see what the alignment is like at my intial timing (18 deg) and compare it to a stock (4 degrees adv) and see the alignment
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Re: Distributor phasing is a good idea
[Re: aarcuda]
#312416
05/11/09 01:10 PM
05/11/09 01:10 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Can anyone provide a definitive "reality check" to this post? I've owned a number of Mopars, using several different distributors over the years and have been envolved with many many friends "back in the day" as well as having tuned up hundreds on the scope when I worked at Miramar.
You are using terms like "most need alignment"
I don't remember seeing all that many with badly burned caps--the one physical indication of misalignment
Second, there IS CONSIDERABLE leeway in the cap. As the rotor rotates, the corner of the leading edge of the rotor comes "to" the corner of one edge of the cap contact. They then move past each other, to the opposite "corner" of each contact. That must be a dimension close to or better than 3/8"!!!!
You say "your car runs better." Have you proof of this? You showed a picture of what I would call a MASSIVE reluctor misalignment, and imply that you've checked that against a cap, and that is a "typical" situation. Frankly, I find that a little hard to believe.
Last, why are we just hearing about this now? For years and years, various people have been making high performance igniton, people like Mallory, Accell, Vertex, and a few I've forgotten
AND NOT ONCE in any advertisements for these products have there been blazing headlines about how necessary it is to "cure" the awful rotor phasing in Mopar distributors.
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Re: Distributor phasing is a good idea
#312417
05/11/09 01:22 PM
05/11/09 01:22 PM
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Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
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master
Joined: Dec 2006
Posts: 3,533
Indiana
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My statistical data: Out of probably 6-7 cars that I converted to electronic ignition via the MP kit (and for street use only, if that matters), most of which had MSD ignition boxes (either the 5 or 6), and over a 15-year period... Only 1 displayed any issues that were corrected via rotor phasing. Would the others have run better if I experimented with phasing? I don't know...  I'd file this issue under the 'things to keep in mind' category.
Parts I seek:
driver doorpanel, 65 Sport Fury, prefer black, needs to be 7-8 on 10 scale, might buy set
16" x 6" Dodge truck wheel(s), from early 70s?, takes 9" dogdish - need for a research job so cheaper is better.
69-73 C-body caliper brackets and/or splashields
Send a PM.
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Re: Distributor phasing is a good idea
[Re: aarcuda]
#312418
05/11/09 01:32 PM
05/11/09 01:32 PM
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Joined: Jan 2003
Posts: 9,982
Ansonia, CT
CJK440
master
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master
Joined: Jan 2003
Posts: 9,982
Ansonia, CT
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Quote:
i dont believe thats true. i believe mechanical advance as well as the initial timing will change the orientation pickup /cap terminal to the rotor/reluctor spline
the relationship of the rotor tip and star wheel is fixed to the distrib shaft and is driven by the cam (but the relationship can be adjusted as stated above).
The cap terminal is fixed to the body of the distrib housing and will be moved back and forth as the housing is twisted CW or CCW.
When the housing is twisted CW or CCW, the pickup moved forward or aft of the reluctor. thats how mech timing is adjusted. Move housing so the pickup moved toward the reluctor spline and the coil fires off earlier thereby advancing it. move it away, the timing is retarded.
When the coil fires it sends the pulse down to the rotor to arc out to a plug terminal. it WILL JUMP A GAP here. the question is how much.
as the centrifigal advance kicks in, the rotor and the reluctor move so that the reluctor spline moves towards the pickup thereby advancing it
Now, i would imagine the width of the conductor on the tip of the rotor is such that one corner of it aligns with the front edge of the 1/4 wide contact on the cap and as the engine advances, the rotor contact swings through the terminal contact.
point is, the mech and the vac advance changes the relationship of the reluctor spline to the pickup. since the reluctor spline is tied to the rotor it will move in relation to the housing annd the cap terminal is tied to the housing.
Ignoring vac advance for a second.
The reluctor passing by the pickup is what triggers the coil to fire. When it does fire you want the rotor lined up with the cap terminal.
Since intial advance (rotating the distributor in the block) shifts the cap and pickup together as one, and centrifugal advance moves the rotor and the reluctor together as one the timing of when these events occur in relation to the crank may change but the rotor will always be in the same position in relation to the cap when the reluctor tooth lines up with the pickup.
The only thing that will change this is when the vacuum advance pulls the pickup around in relation to the cap terminal.
2017 Contusion Blue Challenger T/A 392 M6 "BLKNBLU"
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Re: Distributor phasing is a good idea
[Re: CJK440]
#312419
05/11/09 01:41 PM
05/11/09 01:41 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Quote:
i dont believe thats true. i believe mechanical advance as well as the initial timing will change the orientation pickup /cap terminal to the rotor/reluctor spline
the relationship of the rotor tip and star wheel is fixed to the distrib shaft and is driven by the cam (but the relationship can be adjusted as stated above).
The cap terminal is fixed to the body of the distrib housing and will be moved back and forth as the housing is twisted CW or CCW.
When the housing is twisted CW or CCW, the pickup moved forward or aft of the reluctor. thats how mech timing is adjusted. Move housing so the pickup moved toward the reluctor spline and the coil fires off earlier thereby advancing it. move it away, the timing is retarded.
When the coil fires it sends the pulse down to the rotor to arc out to a plug terminal. it WILL JUMP A GAP here. the question is how much.
as the centrifigal advance kicks in, the rotor and the reluctor move so that the reluctor spline moves towards the pickup thereby advancing it
Now, i would imagine the width of the conductor on the tip of the rotor is such that one corner of it aligns with the front edge of the 1/4 wide contact on the cap and as the engine advances, the rotor contact swings through the terminal contact.
point is, the mech and the vac advance changes the relationship of the reluctor spline to the pickup. since the reluctor spline is tied to the rotor it will move in relation to the housing annd the cap terminal is tied to the housing.
Ignoring vac advance for a second.
The reluctor passing by the pickup is what triggers the coil to fire. When it does fire you want the rotor lined up with the cap terminal.
Since intial advance (rotating the distributor in the block) shifts the cap and pickup together as one, and centrifugal advance moves the rotor and the reluctor together as one the timing of when these events occur in relation to the crank may change but the rotor will always be in the same position in relation to the cap when the reluctor tooth lines up with the pickup.
The only thing that will change this is when the vacuum advance pulls the pickup around in relation to the cap terminal.
To simplifiy ( I hope) this further, the rotor and reluctor/ points cam ARE ON THE SAME SHAFT so the mechanical advance has nothing to do with a change in phasing. Neither does changing initial timing.
the only thing that can affect phasing CHANGE is the vacuum advance or problems with the advance plate--loose, misaligned, etc.
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Re: Distributor phasing is a good idea
[Re: AndyF]
#312421
05/11/09 02:30 PM
05/11/09 02:30 PM
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Joined: Jan 2005
Posts: 12,492
Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,492
Kalispell Mt.
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Most important part is to get the rotor centerd in the termanal when it fires across the gap. It changes. My method is always simple, run it for a while with a new cap, there will always be some burning on the terminals and rotor, look if most burning is centered in the center of the tip of both rotor and cap terminal, this will be where YOUR engine spends most of its time and will be most important to YOU, then adjust acordingly (whatever method you prefer)to get the burn spot in the center.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Distributor phasing is a good idea
[Re: HotRodDave]
#312422
05/11/09 03:45 PM
05/11/09 03:45 PM
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Joined: Jul 2003
Posts: 2,637
Western Michigan
68Fastback
master
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master
Joined: Jul 2003
Posts: 2,637
Western Michigan
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Quote:
Most important part is to get the rotor centerd in the termanal when it fires across the gap. It changes. My method is always simple, run it for a while with a new cap, there will always be some burning on the terminals and rotor, look if most burning is centered in the center of the tip of both rotor and cap terminal, this will be where YOUR engine spends most of its time and will be most important to YOU, then adjust acordingly (whatever method you prefer)to get the burn spot in the center.
On one of my caps inside the terminal was burned evenly across, what might that indicate.
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Re: Distributor phasing is a good idea
#312423
05/11/09 04:35 PM
05/11/09 04:35 PM
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Joined: Mar 2003
Posts: 15,493
the boonies
aarcuda
I Live Here
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I Live Here
Joined: Mar 2003
Posts: 15,493
the boonies
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Quote:
Quote:
Quote:
i dont believe thats true. i believe mechanical advance as well as the initial timing will change the orientation pickup /cap terminal to the rotor/reluctor spline
the relationship of the rotor tip and star wheel is fixed to the distrib shaft and is driven by the cam (but the relationship can be adjusted as stated above).
The cap terminal is fixed to the body of the distrib housing and will be moved back and forth as the housing is twisted CW or CCW.
When the housing is twisted CW or CCW, the pickup moved forward or aft of the reluctor. thats how mech timing is adjusted. Move housing so the pickup moved toward the reluctor spline and the coil fires off earlier thereby advancing it. move it away, the timing is retarded.
When the coil fires it sends the pulse down to the rotor to arc out to a plug terminal. it WILL JUMP A GAP here. the question is how much.
as the centrifigal advance kicks in, the rotor and the reluctor move so that the reluctor spline moves towards the pickup thereby advancing it
Now, i would imagine the width of the conductor on the tip of the rotor is such that one corner of it aligns with the front edge of the 1/4 wide contact on the cap and as the engine advances, the rotor contact swings through the terminal contact.
point is, the mech and the vac advance changes the relationship of the reluctor spline to the pickup. since the reluctor spline is tied to the rotor it will move in relation to the housing annd the cap terminal is tied to the housing.
Ignoring vac advance for a second.
The reluctor passing by the pickup is what triggers the coil to fire. When it does fire you want the rotor lined up with the cap terminal.
Since intial advance (rotating the distributor in the block) shifts the cap and pickup together as one, and centrifugal advance moves the rotor and the reluctor together as one the timing of when these events occur in relation to the crank may change but the rotor will always be in the same position in relation to the cap when the reluctor tooth lines up with the pickup.
The only thing that will change this is when the vacuum advance pulls the pickup around in relation to the cap terminal.
To simplifiy ( I hope) this further, the rotor and reluctor/ points cam ARE ON THE SAME SHAFT so the mechanical advance has nothing to do with a change in phasing. Neither does changing initial timing.
the only thing that can affect phasing CHANGE is the vacuum advance or problems with the advance plate--loose, misaligned, etc.
the mechnical advance rotates the slotted plate (wrt to the pickup) which IS the rotor/reluctor mount.
So as the mechanical advance kicks in, it moves the rotor and reluctor wrt to the pickup, so the rotors alignment wrt the cap contact changes cause the cap contact didnt move. it has to
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Re: Distributor phasing is a good idea
[Re: aarcuda]
#312425
05/11/09 06:51 PM
05/11/09 06:51 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
So as the mechanical advance kicks in, it moves the rotor and reluctor wrt to the pickup, so the rotors alignment wrt the cap contact changes cause the cap contact didnt move. it has to
NO!!!!!
You are not thinking correctly. As the mechanical advance rotates BOTH the reluctor AND the rotor change TOGETHER. Their mutual relationship DOES NOT CHANGE.
There are two relationships here.
ONE THe relationship between the points/ reluctor and the CAP
TWO The fixed relationship between the rotor and reluctor.
If the reluctor is off in relation to the rotor, you have a phasing problem.
BUT ONCE YOU FIX/ verify that, then the postion of the mechanical advance means not. THEY ROTATE TOGETHER
The vacuum plate DOES move the pickup/ points, which changes position IN RELATION TO THE CAP
You can NEVER have absolute dead center phasing with a vacuum advance, because THIS MUST HAPPEN. so now you have two choices:
ONE Optimise the vacuum advance position and live with what should be minor phasing change, or
TWO Align the phasing perfectly and weld the advance plate and do without vacuum advance.
I've seen hundreds and HUNDREDS of caps and rotors in my lifetime, and I'm getting to be on in years. In my opinion, this is an overblown "problem"
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Re: Distributor phasing is a good idea
[Re: sch1966]
#312429
05/13/09 11:10 AM
05/13/09 11:10 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
I dont run vacuum advance. only mechanical.
ditto!
I think vacuum advance in a steet driven hot rod or strip operated car is meaningless anyway unless you frequently drive long distances.
I've gotten 14mpg out of a warmed over 440 doing 70mph with 3.23 gears and mechanical advance only. Better than I ever thought I'd get!
I can't tell you how many Mopar electronic distributors I've gone through for friends because they just can't get their car to run properly! It's not like it's a black art, they just treat it like it is!
Stuck weights, broken springs, and nasty corroded internals are all par for the course. 
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Re: Distributor phasing is a good idea
[Re: ThermoQuad]
#312430
05/13/09 11:25 AM
05/13/09 11:25 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Wow the cauldron of discontent...
I am amazed that a simple check for a problem and a fix that really works gets so much discourse.
Phasing works and the car runs better. Another perfect example of why some cars are faster & run better than others.
I have checked a number of used caps-the good ones-not the elcheepos-and there is no geometric tolerancing problem with the index slot and the positioning of the terminals. Are there any other forensic questions??
Here is a pic of the test cap terminals,that came off an un-phased distributor. Please look at the pic post #1 and look at the difference. Higher resistance in an electrical path reduces the efficiency of the circuit. E=IR
You keep making wild statements like "the car runs better" but you haven't been able to back this up with any factual evidence.
You show us this one cap, here, and proclaim that it is an example of the badness at hand, but....evidently you have run no electrical analysis on this specific cap/ dist setup. You should be able to actually MEASURE the loss of power and possibly see it on an ignition scope.
I=E/R indeed. The secondary circuit is by nature a VERY high impedance circuit BY DESIGN. Let's add up the losses:
Several ohms in the two terminal connections at the coil/ cap tower, net loss= nearly zero
More than several ohms in the coil resistance wire (if used) and more yet in the resistor plug wires (if used)
A few more ohms lost in the terminal connections at the plug wire ends
MANY ohms lost --by design--at the rotor contact and gap. BEAR IN MIND that in the case of GM a "short" rotor was used on some cars BY DESIGN so in this case we are talking EVEN MORE gap
Now to the plugs. Some plugs have a gap in the insulator, some are resistor, and nearly all have a spring loaded arraingment in the ceramic, a few more ohms lost, and of course finally...
We have the plug gap itself, and whatever the firing conditions are in the chamber
The point? The HT voltage has got to be WAY more powerful than any of these losses, which are in the system by design and by necessity.
Now you post this last picture....how do you know that this cap is a problem? I see no obvious tracking on the cap, it MAY WELL BE POSSIBLE that as I mentioned earlier, the "corners" of the rotor/ contact came into alignment as the spark fired, and it stopped where you see the end of the arc in the middle of the contact. Or, the other way around.
YOU STILL HAVE NOT presented any viable proof that what you are presenting here is actually making any difference in performance, and worse yet, any quantifiable evidence of how good or bad the situation gets with a given misalignment, for example, .020" off from center causes 5hp loss, etc.
I guess the point I'm trying to make is that you simply haven't proved your arguement. There may well be bigger fish to fry. Spark scatter, for instance, has always been a problem with factory Mopar ignition, due partly to the design of the dist. drive and the dist. itself, and of course slop in the cam drive. It may well be, for example, that while you are fine tuning the dist for phasing, you may well have bad enough scatter that your efforts are for naught.
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Re: Distributor phasing is a good idea
[Re: 68Fastback]
#312433
05/19/09 05:45 AM
05/19/09 05:45 AM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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Quote:
I double checked my setup and on two of the cylinders the reluctor gap is tighter than the other six. Is this ok.
You can trim the 2 teeth(gap & angle of the gap) & you would want the (min) gap at the closest teeth but 1st w a vacuum pump pull the vac can thru its range of travel & check clearances of each & every tooth. Alot of work but this kind of detail(in every system of the car) will let you outrun the next guy. EDIT you might contact Nacho as he has done extensive work with this issue.
Last edited by RapidRobert; 05/19/09 08:14 AM.
live every 24 hour block of time like it's your last day on earth
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Re: Distributor phasing is a good idea
[Re: 68Fastback]
#312434
05/19/09 06:53 AM
05/19/09 06:53 AM
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Joined: Mar 2003
Posts: 15,493
the boonies
aarcuda
I Live Here
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I Live Here
Joined: Mar 2003
Posts: 15,493
the boonies
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Quote:
I double checked my setup and on two of the cylinders the reluctor gap is tighter than the other six. Is this ok.
that might be because the shaft is moving
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