Distributor indexing
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,990
From: Connecticut, USA
Distributor indexing
Where are you guys running the vac can in relation to the valve cover?
I never use the chrome sheilding and have set them so the vac can is pointing to the # 6 cylinder area.I checked the AIM and it shows it behind #8, must be for the sheilding clearence? that might put a kink in the tach cable?
Gary
I never use the chrome sheilding and have set them so the vac can is pointing to the # 6 cylinder area.I checked the AIM and it shows it behind #8, must be for the sheilding clearence? that might put a kink in the tach cable?
Gary
Pro
Joined: Sep 2000
Posts: 552
Likes: 0
From: Oneida WI
I had a discussion with Lars on this subject a couple yrs. ago and he pointed out that the distributor shaft has a hole in it which lines up with a hole in the block for oiling purposes. This would put the vacuum advance canister ahead of shielding. Pointing towards the #6 cyclinder.
Instructor
Joined: Jun 2004
Posts: 220
Likes: 0
Mine's pointing to the #8 cylinder. After I broke a tach drive gear and wiped out the distributor shaft I switched from 6 to 8. At the # 8 position there is no binding in the tach drive cable and the shield still fits.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Originally Posted by gtr1999
Hi Gordon,
Are you running the sheilding on your car now?
Also are they holding that Crovette show and drag race again this summer at E -Town?
Thanks,
Gary
Are you running the sheilding on your car now?
Also are they holding that Crovette show and drag race again this summer at E -Town?
Thanks,
Gary
Yes they are having the show/race/autocross this year at Etown. It is on August 6th. www.racewaypark.com
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Where ever u want to put it.
U can put that vac can where ever u want as long as u maitain the firing order 18436572 and the rotor points at #1 while TDC/0 degrees(becareful not #6). Yes if your running ign shields u need to pay attention to a dimple on the dist housing & gear to fit the vac can between the intk runner and firewall/ign wire cover/shielding - lars corrected me on this. The old '70 LT1 was really tight with the hi-rise intk runner and ign wire shields with mech tach drive. But i don't use no shields and i'll place that vac can where ever i want - right now it's pointing at #4 or #6. I set mine to reduce bending stress in my mech tach cable - smooth as possible bends - as i have alot of tach error. And if needed i could set at #3 or #5.
Take a little while to figure it but i drew some circles for crank, cam, and dist and numbered them with the firing order. Try it a few times and sleep on it if needed.
cardo0
Take a little while to figure it but i drew some circles for crank, cam, and dist and numbered them with the firing order. Try it a few times and sleep on it if needed.
cardo0
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
Hello,
I had a similar problem with interference between the chrome shields and the vac. cannister. But I also had a large bend in the tach cable going to the tach drive in the distributor.
Someone from the Forum posted a Chevrolet Bulletin that described the solution for this, which was to rotate distributor clockwise, but maintaining the relationship of the firing order. That will allow the distributor to rotate and alllow for a better angle of the tach drive cable, which removes a lot of the strain on it.
As long as the relationship between the firing order, rotor and spark plugs are not changed, you should be able to locate the position of the vac. cannister to where it will not have any interference. If you know the position of the rotor when you take off the distributor cover, and always align the corresponding spark plug wire over that position upon reinstallation, you will still maintain the correct firing order of 18436572
I looked for a copy of the service bulletin but could not find it in my computer. I think that it was sent to me by Paul67
kdf
I had a similar problem with interference between the chrome shields and the vac. cannister. But I also had a large bend in the tach cable going to the tach drive in the distributor.
Someone from the Forum posted a Chevrolet Bulletin that described the solution for this, which was to rotate distributor clockwise, but maintaining the relationship of the firing order. That will allow the distributor to rotate and alllow for a better angle of the tach drive cable, which removes a lot of the strain on it.
As long as the relationship between the firing order, rotor and spark plugs are not changed, you should be able to locate the position of the vac. cannister to where it will not have any interference. If you know the position of the rotor when you take off the distributor cover, and always align the corresponding spark plug wire over that position upon reinstallation, you will still maintain the correct firing order of 18436572
I looked for a copy of the service bulletin but could not find it in my computer. I think that it was sent to me by Paul67
kdf
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Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
Hey Gary, I'm still running the shielding on mine. I didn't like the kink in the tach cable at all. My canister was forward of the shielding upright. I didn't restab the distributor....just jumped the wires over one tower and retimed it. Now my canister is just behind the upright...and the tach cable is nice and straight. I don't know....maybe this is a touch of bubba, but it's worked fine like this for years now.
Last edited by goinbroke; Jul 27, 2005 at 05:54 PM.
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,990
From: Connecticut, USA
To follow up I just got back to this. I looked at the alignment of the can in the #8 position vs the #6 and didn't like the #6 strain on the tach cable. The cabel had a "S" bend to it at #6 and the tach will stop at times. I bought a new cable from Bairs and will index ti at #8 like the AIM shows. I do llike the fact the oil hole lines up in the block though so I'm going to mill a slot in the housing where the hole is to open it up enough to have the oiling at #8.
Here is the present stock setup. If you look you'll see the chisel mark from the factory to align it to the manifold and the #8 spot. I marked the center line of the block hole in red on the distributo too to show where the slot needs to be positioned. I don;t know how much it really matters and if I didn't have access to a Bridgeport I would even bother.
Gary
Here is the present stock setup. If you look you'll see the chisel mark from the factory to align it to the manifold and the #8 spot. I marked the center line of the block hole in red on the distributo too to show where the slot needs to be positioned. I don;t know how much it really matters and if I didn't have access to a Bridgeport I would even bother.
Gary
