BB Distributor Orientation Question--
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 3,023
Likes: 2
From: TEXASTEXASTEXASTEXAS TEXASTEXASTEXASTEXAS
St. Jude Contributor
BB Distributor Orientation Question--
I haven't had my vacuum advance hooked up in the past, so I haven't worried about this, but I just installed a new adjustable vacuum can & want to hook it up.
Here's the problem. The way it was when I pulled it out of the car, the outlet for the can is pointed directly at the support for the distributor sheilding--no way to attach the hose. If I shift the wires around one tower clockwise, the outlet points foward enough to clear the support nicely, but there's no way to get the distributor body that far clockwise with the tach cable hooked up--just won't go that far. If I shift them counter-clockwise, the vacuum can ends up against the firewall and I have no play for setting timing.
How is it supposed to be oriented stock? Is the little dwell setting door supposed to be squarely facing the front of the car (that's the position where I can't get it to with tach cable attached)? Do I just have to resign myself to getting one of those right angle adapters for the tach cable. I don't really want to do that because I understand it can cause excessive wear on the tach gear.
JB
Here's the problem. The way it was when I pulled it out of the car, the outlet for the can is pointed directly at the support for the distributor sheilding--no way to attach the hose. If I shift the wires around one tower clockwise, the outlet points foward enough to clear the support nicely, but there's no way to get the distributor body that far clockwise with the tach cable hooked up--just won't go that far. If I shift them counter-clockwise, the vacuum can ends up against the firewall and I have no play for setting timing.
How is it supposed to be oriented stock? Is the little dwell setting door supposed to be squarely facing the front of the car (that's the position where I can't get it to with tach cable attached)? Do I just have to resign myself to getting one of those right angle adapters for the tach cable. I don't really want to do that because I understand it can cause excessive wear on the tach gear.
JB
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: BB Distributor Orientation Question-- (JB)
I bet somewhere down the line someone removed the dist and when they put it back in the had it one tooth off. On vettes with the tach drive and ignition shielding there is only one correct way to drop the dist in. On many other cars its not such a big deal since the dist will rotate far enough to compensate. I delt with this when dropping my dist back in after a cam swap. On the vettes yur movement is limited by the tach cable. so theres only one way everything will work. I had to play with mine in different positions(tooth engagement) and wire positions till I finally found the one and only way to make everything work the way it was intended. If you do decide to try a different tooth engagement position, youll also have to move the oil pump shaft to a different position to get the dist to fully engage and drop down all the way.
Advanced
Joined: Aug 2000
Posts: 75
Likes: 0
From: Hamilton, OH USA
Re: BB Distributor Orientation Question-- (JB)
I installed mine per the AIM. When installed properly, the centerline of the distributor cap hold-down screws should be 15 degrees CW from being parallel with the firewall. In other words, the vacuum advance nipple should be pointing towards the right front tire, and the dwell window should be slightly offcenter. I am glad I have a tach cable adapter, as I don't think the tach cable would work without it (at least without kinking it). I believe they went to a longer cable because of this.
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Re: BB Distributor Orientation Question-- (JB)
If you don't solve the mystery, don't worry. Just make it run well enough to get to San Antonio in a couple of weeks! :yesnod:
Melting Slicks
Joined: Jun 2001
Posts: 2,340
Likes: 2
From: Moro IL
Re: BB Distributor Orientation Question-- (JB)
JB, mines set up very close to how you described, my vacuum line has to make a pretty hard turn out of the canister to clear the shielding support.
:cheers:
Pat Kunz
:cheers:
Pat Kunz
Safety Car
Joined: Dec 1999
Posts: 4,148
Likes: 5
From: Roxbury NJ
Re: BB Distributor Orientation Question-- (73 LS-4)
Mine is real tight too, but it works just fine. The tach cable is bent and pressed against the firewall when the advance can is pointed out the correct opening in the shield. Unfortunately, there's no good way to fix it with the stock parts, since the tach drive and vacuum canister are both firmly attached to the distributor body. Stabbing the distributor into another position will rotate the whole thing, then nothing will fit.
