BBSC lost belt/pulley while cruising...pics request of BBSC part

[annointed]

OK, so this afternoon I was about 3 miles from my house, when I heard a quick metallic ping and the sound of a small piece of metal bounce once or twice in the engine bay. The sound of the supercharger instantly ceased, and the battery light came on, which led me to believe I lost my SC belt.

Sure enough, that's what happened. I'm attaching pics. Does anyone have some pics of the pulley and the metal stub that the pulley mounts onto? It appears the pulley was loose and ate into the metal stub, rounding it off somewhat, especially toward the tip of the stub...but I've never seen these parts, and if others can post some pics of how theirs looks, that would be helpful. Also, the shaft the pulley mounts to still spins, so I assume my supercharger didn't sieze.

I lost the fastener that holds the pulley on. Apparently that was the metal that jingled around in the engine bay behind me.

Anyway, I'm looking for opinions on the pulley and it's mount, as I think mine looks like it was messed up by this incident. The pulley might be ok, but even it appears to have been eaten into inside the mount hold. If the pulley was loose, it could have been gradually eating away the metal that it mounts to over time until the bolt finally backed all the way out today.

Pics:

 

[96cxt]

Dang that sucks. I'll try and take pictures tomorrow.

 

[RON98]

lucky it didn't shred your fuel line.
person who did the install should be shot.:tongue:

 

[96cxt]

when you put the pulley back on, make sure you use the blue loctite on the bolt holding the pulley to the shaft.

 

[annointed]

Thanks for the support, fellas

I'd still greatly appreciate seeing other people's pictures of the pulley mount, as I'm wondering if mine is rounded off, in which case I'll start shopping for a new one. A phone conversation I had yesterday with a member who's owned a BBSC for years suggested that the way mine looks might actually be normal.

Also, I'm having a heck of a time figuring out the size bolt that the pulley mount is threaded for. None of the bolts I have on hand fit, although my tap/die set worked best with a 9x1.25 tap. Local stores don't have any 9mm bolts Tomorrow I'm going to visit a fastener specialty store, as they should have a high quality bolt that works.

Also, I bought a stock alternator belt from NAPA, so I can bypass the SC pulley to at least drive the car. Once the BBSC is back online, I'll also start keeping the stock belt and requisite tools in the trunk, just in case this ever happens again when I'm not so close to home, so I won't have to drive on battery power alone.

 

[annointed]

OK, I cannot find any place that has a 9mm x1.25 bolt. Apparently 9 mm is a virtually non-existent bolt, although it appears to be the size tap that worked in the hole (if my tap/die set has 9mm, then 9mm bolts must exist).

Does anyone have a BBSC kit laying around who can verify the size of the bolt for me? It is the bolt/fastener that holds the supercharger pulley in place.

I even drove to a fastener specialty place, and he had ZERO 9 mm bolts, even in his catalogs of special order bolts.

Maybe I don't have the bolt size correct. Any help is appreciated!

Thanks.

 

[peiserg]

It is a 3/8 fine thread bolt. NOT metric. that's from basch's mouth.

 

[annointed]

It is a 3/8 fine thread bolt. NOT metric. that's from basch's mouth.

Ah, so it is. I just tried my 3/8 x 24 tap and it went in smoothly the whole way. I don't know how I missed using that one yesterday.:redface: The difference can only be attributed to the fact that I'm sipping Yuengling this evening, unlike yesterday! :tongue:

 

[kj5000]

Here are some photos of mine. I measured the shaft and pully with a caliper. The shaft/pulley are hex shaped so min/max. My pulley has about 1mm arc of play when I wiggle it on the shaft without the bolt.

Hope this helps.

Shaft min 15.6 - 15.7
Shaft max 16.5 - 16.6
Pulley min 15.4 - 15.6
Pulley max 16.6 - 16.7

 

[annointed]

Here are some photos of mine. I measured the shaft and pully with a caliper. The shaft/pulley are hex shaped so min/max. My pulley has about 1mm arc of play when I wiggle it on the shaft without the bolt.

Hope this helps.

Shaft min 15.6 - 15.7
Shaft max 16.5 - 16.6
Pulley min 15.4 - 15.6
Pulley max 16.6 - 16.7

Now that is finally what I was looking for. Comparing your pics to mine confirms that my parts are damaged. The entire center hex section of my pulley is gone, except for that last 1/8 of an inch. At this point I need a machine shop to work some magic, or some new parts

I was wondering if another means of securing the pulley could work, such as a woodruff key?

Anyway, thank you so much for taking the time to take the pics/measurements and post them.

 

[96cxt]

Yeah the pulley is hex all the way thru and so is the pulley side of the shaft. You should be able to get away with having a key way cut in the shaft and pulley and using a W.key

 

[factorynsxtech]

What belt does it use or size?

 

[syam]

for securing the pulley to the hex shaft, you could have a stud inserted into the shaft secured using green loctite (this stuff is ridiculous) and use either a flange locking nut or a locking nut with washer to secure the pulley.

machining a small keyway into the shaft and the pulley is also a good idea, but will be expensive as a lot more machining time is needed, along with very specialized tools such as a broaching setup for the internal keyway.

 

[96cxt]

What belt does it use or size?

I have been going back and forth for the past 4 days trying to get the right size belt.

so its a 672k6 which means 67.2" and 6 rib belt. This depends on the size pulley you have on the shaft.
hope this helps.

Rahim

 

[annointed]

The belt on mine with 6 psi pulley was Napa 25-060672, which measures 13/16" x 67 3/4", or 20mm x 1722mm.

 

[96cxt]

The belt on mine with 6 psi pulley was Napa 25-060672, which measures 13/16" x 67 3/4", or 20mm x 1722mm.

The Napa part is 060672 = 06 (ribs) and 0672 (67.2")

Are you measuring a used belt?

 

[annointed]

The Napa part is 060672 = 06 (ribs) and 0672 (67.2")

Are you measuring a used belt?

Nope, on Sunday I bought a new belt from Napa and am quoting the measurements from the packaging that bundles the new belt, although your explanation of their part code is intriguing:tongue: Weird that it says 67 3/4" on the back of the packaging.

 

[factorynsxtech]

Thanks guys

 

[WOODY]

do yourself a favor and get a gatorback belt to decrease slippage

 

[4AU4LIFE]

do yourself a favor and get a gatorback belt to decrease slippage

+1.
I have heard this from more than one person that is very knowledgable with the BBSC.

 

[annointed]

do yourself a favor and get a gatorback belt to decrease slippage

Cool, I'll pick one up, thanks.

For now I'm still bypassing the supercharger until I find a replacement pulley and get to a local machine shop to have them make me a new rod.

 

[Chuck]

The part number for the Gaterback Belt used with the stock pulley with the Novi 1000 is 4060672. Remember, the belt is officially NASCAR licensed so it must be good:smile: