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Discussion Starter #1
I have a 66 289 4vv. According to Ponycarbs when the car's timing is correct. The centerline of the vaccuum advance should be pointing at 7 o'clock. So if you are standing at the front of the car looking at the firewall. The fireweall would be 12 o'clock and the radiator would be 6 o'clock. The centerline of the vaccuum advance on mine is pointing at 6 o'clock. So I think my distributor is off by a tooth. Anyone know which way to turn the rotor so that when my car is timed the Vac Adv is in the right position at 7 o'clock?
 
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Every 289 I've worked on, I've put it at 6 o'clock...but in reality, it doesn't matter which way your distributor points as long as it is spun to a spot where the timing is right. You don't specifically say that your timing is off...or it is OK.

If it were me, I'd slap a timing light on it, make sure it was to spec (about 6 deg BDC), then worry about something else. I'm not trying to b flip about it...sorry if it comes across that way, but functionally, the 6 o'clock position is fine if everything is timed right.
 

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I think this is splitting hairs here. If there is ample room to move the distuibutor in the clockwize and counter clockwize directions, to get the proper timing than leave the distributor where it is.

If the proper timing can not be found, than move the distributor shaft one tooth clockwize and put it back in the hole. This may even cause it to over shoot but that seems to be what you want to try. You will than also have to contend with lining up the pump drive also.

Once again, if the timing is correct like it is pointing at 6 OC than leave it alone. John
 

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Discussion Starter #4
I have put a light on it. It is correct. But at this popsition I don't have any room to get a wrench on the distributor lock down bolt. The A/C unit is in the way. I come in from the water temp side and the timing cover gets in the way. But if I move the distributor in the 7 o'clock position i have room to get a wrench on the bolt and tighten it down.
 

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Well as an alternative you could also move the cap wires one hole. If one hole is indexed for the #1 plug than this could cause a little confusion but otherwize it would be an easy fix. John
 

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Usually the only time people's distributor is "off a tooth" is when they can't twist the distributor far enough to get it in time because it hits the valve cover or the thermostat housing. As long as the vacuum advance can is positioned so that your timing is correct (according to a timing light) and you have some room to adjust it some more if needed, you're fine.
Technically, if the other bits of the engine weren't in the way, you could juggle the the distributor and wires around to time the car correctly with the vacuum advance pointing to any position on the "clock" that you like. I believe Pony Carb's statement was meant to be just an estimation, not a hard rule.
 

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Ah, they make special wrench bent at a 90 degree angle just for this. Distributor hold downs are notorious for being difficult to get a wrench on. I wouldn't change the timing just for wrench access.
 
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Well, you can bump the distributor by a tooth and get it to 7 o'clock if that helps. Here is how to handle that...

What needs to be maintained is the rotors pointing position in relation to the distributor housing. For arguments sake, lets say the rotor is pointing right at the advance unit (it helps to mark it - make a dot on the distributor housing). When all is said and done, you need to have the rotor pointing back to this position on the housing regardless of where the distributor housing points.

With that knowledge, you can pull the distributor up and rotate the housing one tooth left to it's new position.

The only troble you sometimes have is the oil pump shaft at the bottom of the distributor sometimes won't let the distributor drop back in the whole way. Give the distributor a wiggle and you should be ok.

Two other things - that oil pump shaft can come out of the oil pump altogether...typical small problem blowing up into a bigger one. Originally, there is a little lockwasher of sorts on the shaft to keep the shaft in place. More than one build skips that piece.

Last, if you get lost and the distributor gets all out of whack timing wise and you cant get the teeth to line up, you need to go back to square one...get the #1 cylinder to top-dead-center and then get the distributor in place so the rotor points at #1 position on the distributor cap.

This is a lot to absorb...chapters are written in books on this...hope this helps ::
 
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