Can a distributor REALLY be one tooth off? lets discuss this...

99FiveOh

10 Year Member
May 20, 2006
2,050
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99
J-Ville, FL
I see it all the time here and other forums. "I stabbed my dizzy, car runs like crap...."

Then someone says something to this effect:

"Your dizzy is one tooth off, pull it out and restab it in the correct position."

Now, even if you restab it with the rotor pointing in a total opposite direction, you could, in theory, turn the dizzy all the way around and find your timing again.

No matter where the rotor is pointing, you can ALWAYS line it back up. Now, is it one tooth off in relation to the original position? Yes, it can be. Most dizzy's have a little notch on the bottom that lines up with a notch in the block. If you want those notches to line up again then you must get it right on the money.

However, if you don't get the notches lined back up and it IS timed correctly via timing light, it will the EXACTLY the same as it was before, and this will NOT cause the engine to run any worse than if those little "notches" did line up.

This is one of my pieves when I see that kind of advice given about being a tooth off :eek:

What are you guys' thoughts on this? :shrug:
 
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hmmmm....


So you're saying that you can pretty much throw the dizzy in and not worry about where its at and just simply advance or retard it until you get the right timing to get the engine to start?


I guess that makes sense...once you "mesh" the gears on the dizzy gear you turn the dizzy to advance the timing, which you could have actually got that timing by going in at a different tooth.
 
Agreed, the "one tooth off" thing is BS for our cars. You can be 180* out, which refers to the relation between the crank and cam - the crank turns twice for every turn of the cam. I suppose you could be "one tooth off" if there isn't enough reach in the spark plug wires or in the harness to the PIP in the distributor, but that's a different situation.

Now, it's good to mark where the rotor is pointing when removing the distributor, so it's easier to re-time the engine afterward - you should then be close to your original timing. But if you're off a tooth, just rotate the distributor to re-set your timing.
 
nice! So we're in agreement. No posts to the contrary yet. I see this all the time and I tried thinking about it in my mind how the dizzy could possibly be a tooth off but I couldn't come up with a good answer. It actually kept me up for a little while last night! I know, I know.. get a life right....
 
Now, even if you restab it with the rotor pointing in a total opposite direction, you could, in theory, turn the dizzy all the way around and find your timing again.

This is one of the things you gotta look at :D

No matter where the rotor is pointing, you can ALWAYS line it back up.

This is the other thing you gotta look at :D

I've always seen it as ... Its all about how you reference the dizzy :)

In the real world ... You can't always get it to work if the dizzy is one or
two teeth off in one direction or the other

You got plug wires that won't stretch or something that gets in the
way of twisting the dizzy enough to be in time :(

Some cars have more of those issues than others :shrug:

Yes ... if one can twist the dizzy enough ... it can't be off a tooth or two
then again
If one has a concern to put it back EXACTALY as it was before they pulled it

Then ... Sure it can be off a tooth or two and they will find it won't have
the same range of movement in both directions as it did before they
pulled it to do the work.

You just gotta see the bigger picture

I can assure you ... some of the cars that had sbf's of old ...
They did not have all that much range of twisting ability

Hey ... maybe its like that old saying :shrug:

You say too maa tow ... I say too mau tow :rlaugh:

Grady
 
The only place it really applies is when the gears are really worn in. I've seen certain cars where it was a tooth off, and it made a slight whining noise because the gears had worn together in a certain pattern. From an ignition standpoint though, it doesn't matter.

Kurt
 
Sounds like something I've been saying for a long time on here now. :)

I think where a lot of the idea comes from is that in the old days if you were a mile off on your stab, you could shift all your plug wires around and get it to run fine. With our PIPs, you cannot do this.
 
Why can't you be a tooth off?

If you install the dizzy and lets say you mesh the teeth a couple off from where you should be. Then the rotor is not pointng to where it should be so it won't fire. You can't rotate the dizzy enough to make it fire because there might not be enough adjustment. This is why people say you are off a tooth. I have had this happen on my 67. I was a tooth off and the dizzy wouldn't rotate enough let it fire.

Now I have seen guys install them where ever on old school SBF's. They have it on TDC install the dizzy then they put the #1 wire where the rotor is pointing...so now all the wires on the cap are in a different spot but it runs fine.

I would rather keep all my wires at the factory spot so I install it exactly how the factory had it...not a tooth or more off.
 
One tooth off would only put the rotor slightly to the right or left or where it should be, only necessitating a slight turn of the dizzy to compensate.

I think what he meant was leaving the distributor gear itself in place and turning the housing a hair/click (a tooth) right or left (adjusting timing). Again, you will know how far its off right away. If done correctly #1 at TDC, etc. then the guess work is eliminated and so does the myth.
 
I think 1 tooth off is about all that you may have adjustment for in turning the Dizzy to get it to run.
Like Grady said "In the real world ... You can't always get it to work if the dizzy is one or two teeth off in one direction or the other. You got plug wires that won't stretch or something that gets in the way of twisting the dizzy enough to be in time then it won't be even turning both ways."
I agree with his statement.

If you get it retarded then have to turn it to advance it to get it to run you might not have enough adjustment left to advance it more to say 12 or 14 if you wanted to.

Anyway I think what people mean after looking at the start of the thread is that they take it out and when they put it back in it runs bad....so people tell them they are off a tooth. Pull it back out and get it right and it will run o.k. which is true.

Why wouldn't you want it back in the original spot how it was installed from the factory?:shrug: It's not hard to put it in right.
 
I agree, I always end up getting it right back where I started. I just hate when someone is having trouble with their car, or it's not running correctly people suggest the dizzy is a tooth off, which isn't possible if their timing reading is correct 10*, 12* etc. That's all I'm saying.
 
I agree, I always end up getting it right back where I started. I just hate when someone is having trouble with their car, or it's not running correctly people suggest the dizzy is a tooth off, which isn't possible if their timing reading is correct 10*, 12* etc. That's all I'm saying.


Well ... I gotta agree with what you say
but
When those peeps have issues ........

They're just trying to get the dad gum thing to fire :rlaugh:

At that point ... in time :D ... they'd have no clue about spark value :scratch:

Again ... most of this stuff is how you look at it

Like said above ...
I wanna get the dizzy back in like it was before :Word:

Another thing I've always done is .............

You know how everybody says use your finger to feel the air rushing
out of the plug hole to ensure you're on the squeeze stroke

I've never done that :nono:
cause
I'm always by myself and got nobody to turn over the motor :(

I always line everything up and see if it fires off :D

If it won't fire right off :shrug:

I lift up the dizzy and turn the rotor 180 and it always fires up :nice:

I mean it IS or it is NOT on the compression stroke ;)

Grady
 
I've never done that crank it over method. I usually just stick my right nose picking finger in the number one spark plug hole, and turn the engine over with a ratchet with my left hand. When I feel the compression on my nose picking finger, I know it's on the compression stroke, and just turn it till it's about 14 degrees, drop the distributer and line it up. I find it takes about the same time as cranking the engine over, and you get it right every time.

Kurt
 
I've never done that crank it over method. I usually just stick my right nose picking finger in the number one spark plug hole, and turn the engine over with a ratchet with my left hand. When I feel the compression on my nose picking finger, I know it's on the compression stroke, and just turn it till it's about 14 degrees, drop the distributer and line it up. I find it takes about the same time as cranking the engine over, and you get it right every time.

Kurt

LOL old thread.....


but Kurt, im trying to imagine this, dont u mean your left nose picking finger and cranking the engine over with your right hand? Unless you are laying on top of the engine from the driver's side...how can u put your right hand in the #1 cylinder and crank with your left?! :eek:

:p
 
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