Hub centric spacer needed?

I started to assemble the ATI damper and discovered that the aluminum spacer that was hub centric on the stock damper is WAY too small for the opening on the ATI piece. Do I need a custom machined spacer for the ATI damper or the is the remaining 3 bolts enough to center the pulley on the damper?

Here is a picture:

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01665.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01665.jpg)

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01664.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01664.jpg)

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01663-1.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01663-1.jpg)


-B

I don't see why the 3 bolts would not be able to center the hub. Its not like there is that much play in the hub for the bolts to move around.

But best to wait until one of those "experts" come in that have had this issue before :)

You need to machine the spacer so that it pilots into the hub of the ATI balancer. Its not such a big deal because it needs to be tuned anyways to make it thinner as it used to go inside the stock balancer. Machine so the overall pulley height is the same as it was with the stock balancer. Any machine shop with a lathe should be able to handle it for you, just take them all the parts in your pictures. You cannot rely on the bolts to center the pulley and hold it there, they won't.

Rats!! So this means I have to install the hub and balancer to see how it lines up with the SDCE tensioner and remove all of the components to take to the machine shop.

The only problem is that the current spacer is less than 1cm thick so I don't know how they're going to turn the spacer so that it pilots the ATI hub. There isn't enough material. Do I have to get a new spacer from ATI or can the machine shop just cut one?

-B

-B

When you bought the damper from me...... I provided the machining dimensions & belt information to you.

Give me a call & i'll try to help you out.

I checked my old emails and the measurements were there! However I just snapped off the installer rod in the crank snout trying to install the hub. =( That thing is TIGHT especially with 2 key ways.

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01686.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01686.jpg)

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01684.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01684.jpg)

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01683.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01683.jpg)

Its going to be a while before I mess with pulley. =(

-B

Man, that really, really sucks. I've done that very thing. I drilled for days. My suggestion is to have a drill guide made to fit over the crank snout so you drill the bolt dead center. Try to find a left hand drill bit, sometimes you get lucky with the drill bit.

Blown383,

That big block hub will have to honed at a machine shop to make it fit. I had a hell of a time installing that thing. The tolerances on the press fit have to be just perfect. Also I had to buy a balancer install tool from Jegs for 26 bucks. I tried installing it with a grade 8 bolt and it started stripping threads. Sorry that happened to you.:)

Do you have a part number for that balancer install tool from Jegs? Also how much did the machine shop hone the hub? Cost? Thanks!

-B

Update on my snapped crank bolt drama:

I decided to take on this challege myself since I didn't want to haul my $10K motor back to the machine shop and have them tear it apart to remove the broken bolt.

I went to Sears and purchased a hand impact tool that removes frozen or stuck bolts by striking it with a hammer.

I used a dremel and cut a slot in the protruding bolt.

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01690.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01690.jpg)

I slipped on the flat head fitting and slammed on the hammer with no results. The bit just chipped the inside of the slot. =(

So its time to break out the big guns....So I bought a 7/32 and a 1/8 inch Colbalt series drill bit from Sears. The regular black oxide or titanium drill bits won't do sh!t to the bolt so its important to use the Colbalt series.

I 1st drilled a 7/32 hole and tried my best to center it on the bolt.

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01692.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01692.jpg)

Then I used the 1/8 drill bit.

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01694.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01694.jpg)

The Colbalt drill bits went through the metal like a hot knife through butter! =)

I hammered the bolt extractor in and with a pair of vice grips twisted the bolt out.

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01696.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01696.jpg)

This is the result:

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01699.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01699.jpg)

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01701.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01701.jpg)

So inconclusion I would like to give a big THUMBS DOWN! :no: to Autozone's sh!TTY hub installer.

-B

Mine was a .001 press fit:eek: . They ground off about .004 to give me an inside diameter of 1.246. I had to make two trips to the machine shop because they didn't take enough off the first hone. The metal is so thick on the big block hub it doesn't give at all. You'll have to mic your crank and subtract .001 from the outside diameter of your crank. Here is the link for the tool. 15 bucks for the machine work.

http://www.jegs.com/webapp/wcs/stores/servlet/product2_10001_10002_753075_-1

I had my big-block hub machined too. They put a slight taper on the end as well to make it easier to get started when pressing; I can't remember what it's called but it's a common machinist's term for press fit items.

I've always had a new balancer/hub honed before the first install. Recommended tolerance fit is between .001"-.0015". If you have the means to measure the inside diameter of your hub and the outside diameter of your crank snout, the hub should be .001" to .0015" less in diameter than the snout of the crank. If it is anything more (ie. smaller still) then honing is needed. Cost should be $10-$20. Then use the good installation tool and a small amount of anti-seize and it will go together just fine. :D

HOLY CRAP!!!! You guys weren't kidding about the .001 press fit!!! :eek:

Here is the hub:

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01709.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01709.jpg)

Here is the crank:

http://i2.photobucket.com/albums/y26/Blown383/th_DSC01711.jpg (http://i2.photobucket.com/albums/y26/Blown383/DSC01711.jpg)

Now how much should I get the hub honed? I hope I measured correctly.

-B

B,

That slide caliper is probably not accurate enough. Maybe your machine shop would let you use their precision micrometer for the crankshaft measurement. Once you have that measurement just tell them you want a .001 press fit +-.0004. Also, it is better to go a little tight because you can always take more off but; well you know the saying.LOL:)

I hate how this is such a pain in the ass. Try adding a crank trigger into the mix for extra fun. :D

I hate how this is such a pain in the ass. Try adding a crank trigger into the mix for extra fun. :D

Not to steal the thread, but 95 Z/28 LT1, how's the BS3 system working out for you??? Which crank trigger did you choose to run?

I'll let you know in about 3-4 weeks. It's still all coming together at the moment.

I hate how this is such a pain in the ass. Try adding a crank trigger into the mix for extra fun. :D

Dude.... tell me about it..... plus the dual intank fuel system I bought from you is just sitting in a box since I can't run new lines till the motor is in the car. :mad:

-B