L98 Z28

iTrader: (1)

I'm installing a used D1SC in a '92 Camaro. It came with a 12 rib crank pulley, and I swapped that for an 8 rib. When I started the engine, the belt quickly walked back over the engine side of the crank pulley. I pulled the 8 rib pulley off and compared it to the 12 rib, and the 12 rib has less offset and would sit closer to the engine. The belt would likely ride properly on the 12 rib pulley.

It looks like I need to shim the entire mounting plate to get it to sit out farther. Is there a different solution? Anyone else come across this?

Here's some pics of the belt hanging off the crank pulley, and the offset difference in the two pulleys.

no new tires

Did you get the crank pulley hub that Procharger sells? If not buy it.

http://shop.brutespeed.com/ATI-DC009...DC009A-010.htm

Call "Bob" yo see if you can buy the spacer separate.
(its listed in the option break down)

erictheviking

I had the same problem. I didn't extend the spacers for the mounting plate, as it's already not a great design. I cut down the 4 spacers holding the head unit on. Only about 1mm. Still wasn't quite right, so added a washer to the top right one. Works great now. Make sure the blower pulley is exactly straight as well. A good straight edge will show you this

L98 Z28

iTrader: (1)

Both pulleys I have are Procharger's. The one in the link above is for an 8" diameter, I got the dc009a-008 which is the stock 7.65" size.

I considered cutting the head unit's spacers down, but shimming sounded easier (safer) than removing material. Cutting puts images in my head of non-flat surfaces and slightly different length shims. Guess I can look for a metal shop that can do a quality job.

erictheviking

The reason I would suggest removing material, is that the head unit is already really stretching the limits of flexing because the bolts holding the bracket on are already far too long. The whole thing moves because of this. Also, are you using the extra brace between the head unit and back of alternator? But as I also mentioned, having the pulleys dead straight in line makes a huge difference. I also had to shim one of the bolts on the head unit.

L98 Z28

iTrader: (1)

Thanks, Eric. I ended up cutting about 4mm from each of the head unit spacers. Checked alignment with a straight edge and everything looked good. I've run it a little and the belt stays on so far.

I'll post some pictures of my set up in another thread.

erictheviking

Great, see how it goes? You can always shim it back if it needs a bit of adjustment. Mine is very straight now Before I altered it, I had a blower belt shred and come off

9192camaro

Mine has been doing exactly like yours on my 92. Did cutting down the spacers at head unit still keep belt on at high rpm?

L98 Z28

iTrader: (1)

Unfortunately, I don't yet. The car had an oil pan leak that had gotten worse. It took a while to find time to do the repair... and after the repair, the rear still leaks (warped pan maybe?). So, its waiting for me to find more time to try again.

89gta383

iTrader: (5)

Is that pic of the 8 rib 7.65 pulley above with the spacer inside of the pulley, or does the crank pulley have an offset?

I am looking for an 8-rib pulley to use with a vortech, but vortech doesn't sell and 8-rib sbc pulley anymore, only 6 or 10-rib.

DIGGLER

iTrader: (1)

i think i have a vortech 8 rib pulley for an lt1 setup i could sell.....

L98 Z28

iTrader: (1)

The installed picture shows a stock crank pulley, the 8 rib pulley, and you can also see the silver edge of a aluminum spacer behind the 8 rib pulley. I believe the spacer costs as much as the pulley.

The side view pic shows the 12 rib and 8 rib pulleys which have slightly different depths. I don't know what length offset you would need to align with the vortech. The 8 rib may or may not be close to aligning right.

89gta383

iTrader: (5)

The lt1 pulley is like 6.87 or something like that. I want something bigger like the 7.65 or 8.65 so I don't have to run a small blower pulley. I figure if I have to shim the pulley to get the alignment perfect I might as well get the biggest pulley I can find. I didn't know the tpi crank pulley had an offset. The attached pic of the ls1 pulley I bought by mistake is flat. I would use the vortech spacer and then shim from there.

86Z

iTrader: (4)

i added a couple spacers to the two long sleeves to the right of the alternator, that solved my problem, it was the exact same thing as your's, also next time, unplug the coil and just bump the starter a few times to see if the belt tracks off.

L98 Z28

iTrader: (1)

There's also a lip on the bask side that you might have to grind down. Here's someone else's picture that shows the back. It might not be the exact same pulley, but its very similar.

89gta383

iTrader: (5)

So you use the pulley that looks like the above pic with the spacer? Why would you have to grind down that lip?

L98 Z28

iTrader: (1)

My procharger spacer is made to fit with the lip. I don't know what a vortech spacer looks like or if the lip will interfere with it at all.

anesthes

iTrader: (12)

Funny I had the opposite problem, my belt was walking off towards the radiator. I had to add spacers under the crank pulley.

The design is an epic failure.

If you are convinced your balancer is all the way on, you're going to have to take some material off the spacer between the two pulleys.

-- Joe