41 replies to this topic

[mangas]

springer, on 10 January 2011 - 11:40 AM, said:

Scotty and Zachman,  I'll save each of you a pulley.  Jim Clark wants one also.  That leaves one left for now.  They haven't been made yet, so if anyone else needs one, I probably need to know within the next week.  Again, I have one left that isn't spoken for.  The cost for the pulley is $100.

I talked with Peter again today and they should be ready in three weeks.

John

Hi John

This is Peter

The pulleys are  done

call me

[07-2937]

did the whole bash on my 2 year old gates belt  no problems  and i know it bumped the rev limiter many times!!

[springer]

07-2937, on 21 January 2011 - 05:39 PM, said:

did the whole bash on my 2 year old gates belt  no problems  and i know it bumped the rev limiter many times!!

Good for you!  Wish I, and many others, could say the same.  The problem, as I mentioned in another post, doesn't appear to be the belt, but how the belt rides on the 100mm pulley.  So how does your belt ride compared to mine?   On the 100mm pulley, my belt rides at the back of the pulley instead of being centered to slightly off-center on the pulley?

Edited by springer, 26 January 2011 - 07:48 PM.

[SGT/SC#0471]

07-2937, on 21 January 2011 - 05:39 PM, said:

did the whole bash on my 2 year old gates belt  no problems  and i know it bumped the rev limiter many times!!

+1   -the rev limiter part, only got passed by Gary Patterson...and I did some passing...2 novices also drove my car...

[07-2937]

perfectly centered  on stock pullies and thumprrr

[springer]

07-2937, on 22 January 2011 - 09:33 AM, said:

perfectly centered  on stock pullies and thumprrr

That explains it then.  What I think is going on is that the pulley pedestal shoulder on the timing chain cover,where the 100mm pulley goes  through, is not milled the same on every timing chain cover.  If the pedestal shoulder is not milled enough, the pulley will ride too far out from the timing chain cover  where it causes the belt to ride on the back edge of the pulley.  When this happens, under load, the belt walks off the backside of the pulley where the sharp, pulley edges causes it to shred.   My belt is not riding anywhere near the center of the 100mm pulley.  It is riding on the back edge of the pulley.

Edited by springer, 26 January 2011 - 08:31 PM.

[springer]

For those that have been following this thread, today I received my new 100mm idler pulley from Thump RRR.  Peter did an outstanding job on the five pulleys I received.  I've attached some photos of the pulley, along with two photos depicting where the stock pulley and the new 100mm pulley ride on the timing chain cover.  The stock pulley is 7mm from touching the timing chain cover.  The new 100mm pulley rides closer to the cover, and, after subtracting the thickness of the lip (flange), it is 5mm from the timing chain cover.  I know 2 mm doesn't sound like much, but that is the thickness of one rib on a belt.  With the new pulley, belt alignment should be where it was intended and with the addition of the pulley flange, the belt should remain on the pulley now.  I ordered five pulleys and have a couple left if anyone else wants one before I list them in the classified section.  ( Jason, Dave and  Chad, I have one for each of you.  Jim C, this won't fit on the KB supercharger. Your pulley is 76mm or 90mm - definitely smaller than the 100mm.)  The cost is $103 plus shipping.  I also have one new, never installed Gates belt if anyone wants it at $95.

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Edited by springer, 27 January 2011 - 07:24 PM.

[Shelby GT/SC 1685]

Has there been any complaints on the Paxton setup for belt issues?  I've had zero problems.  The belt does come very close to the valve cover I believe.

[springer]

Shelby GT/SC 1685, on 27 January 2011 - 05:36 PM, said:

Has there been any complaints on the Paxton setup for belt issues?  I've had zero problems.  The belt does come very close to the valve cover I believe.

I haven't heard of a belt issue with Paxton superchargers so you're good there!

[zachman]

Checks in the mail.

Thanks again.

Dave

[springer]

Here are some pics from the install of my new 100mm Thump RRR pulley.  I got it on tonight and it works like a champ.  The pulley flange is 2mm away from rubbing the Whipple adjusting bracket, but it clears just fine.  If you notice in the first photo, my belt no longer rides at the edge of the pulley like it did on my original pulley.  The belt now rides 1/4" closer to the center of the pulley.

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Edited by springer, 27 January 2011 - 08:30 PM.

[SGT/SC2873]

springer, on 27 January 2011 - 08:22 PM, said:

Here are some pics from the install of my new 100mm Thump RRR pulley.  I got it on tonight and it works like a champ.  The pulley flange is 2mm away from rubbing the Whipple adjusting bracket, but it clears just fine.  If you notice in the first photo, my belt no longer rides at the edge of the pulley like it did on my original pulley.  The belt now rides 1/4" closer to the center of the pulley.

pm sent

[SGT/SC2873]

John,

I was not able to send you a pm.

I am interested in the pulley and the belt if they are still available.  I do have some questions though to make sure I have all the information to make a decision.  If you will pm your cell, I will give you a call.  thanks, Craig

[springer]

The pulleys are all sold.  SGT/SC 2873 got the last one.  Thanks Craig!

If you are interested in one of these pulleys, contact Peter at Thump RRR Racing.

Edited by springer, 08 February 2011 - 07:31 PM.

[mangas]

springer, on 08 February 2011 - 07:29 PM, said:

The pulleys are all sold.  SGT/SC 2873 got the last one.  Thanks Craig!

If you are interested in one of these pulleys, contact Peter at Thump RRR Racing.

They are on the website with some grooved pulleys

[springer]

mangas, on 24 March 2011 - 12:48 PM, said:

They are on the website with some grooved pulleys

Here is the part number for the Thump RRR Racing flanged 100mm pulley from ThumpRRR.    PM-20100-DF 100 mm Billet Aluminum Rib idler Pulley with Flange $129

Web site address:     http://www.thumpraci...ler_pulleys.htm


Here is the part number for the Thump RRR Racing 87mm grooved idler pulley that is directly below the 100mm idler pulley.  PM-2087-G   87mm Billet Aluminum Grooved Pulley  $79

Wed site address:      http://www.thumpraci...ved_pulleys.htm

Edited by springer, 28 March 2011 - 06:25 PM.

[ShelbyDW]

I too had the shredding issue on the belt.

Several factors seem to make it a perfect storm for the problem. As others, I put the 100mm Thump Dual Bearing idler on the car and the problem was fixed. (for now)

Curiosity drove me to dig a little deeper to find the problem.

1. Once an aluminum casting is machined (idler mount diameter) you will eliminate the hard skin of the casting and the surface is softer and more porous.

2. The inside diameter of the Whipple supplied 100mm bearing is longer than the idler shaft on the casting.

3. There is an air gap between the end of the cast mount and the end of the bearing surface from front to back. Didn’t measure it but guessing its 3-5mm.

4. Since there is no bearing surface at the front of the bearing it can wobble depending on machine tolerances on both the bearing and bearing mount. Reach in there, grab it and if it moves you may have a problem.

5. Any slop will be exaggerated over time and temperature.

6. The change in HP and torque  will exagerate the mis-match over time and use as well.


My Whipple Supplied bearing had 5-10 degrees play while installed and the bolt was torqued to 32 ft/lbs. The bearing in the pulley was good but it fit loose on the on the bearing shaft.

Because the Thump 100mm came with a step washer/bushing it is solid with no movement what so ever. I called and eventually talked to Art Whipple at WI and reviewed the issues. Good guys and they eventually sent me some Stepped washers and a belt for my troubles. I used the stepped washer and put it on the 90mm that had been moved from the driver’s side.

In summary, depending on the setup and QC from all involved there can be enough play in the Pulley standoff and the bushing so that it will deflect enough for the belt to ride off the back of the 100mm idler and shred the belt. My suggestion would be to call WI and ask them to send you the step washer for the 100mm idler if you’re having the problem. It may or may not fix your problem, but it’s the most cost effective start and you still have more options.

Good Luck!

Edited by ShelbyDW, 09 July 2012 - 04:10 PM.

[springer]

Great info, but I was confused after reading your post.  If you used the Thump RRR flanged, twin bearing 100MM idler pulley on the driver's side, which replaces the Whipple/Ford supplied 100MM pulley,  the belt can't come off the backside of the pulley anymore.  The other problem with the Whipple/Ford supplied 100mm idler pulley was that it did not fit close enough to the timing chain cover so when I designed the 100MM idler pulley with Thump RRR, it was milled so that it would fit closer to the timing chain cover which centered the belt much better on the pulley.  

The only other problem I had was with the Thumper RRR single-bearing tensioner arm pulley - the bearing went out and the squeaking was killing me at start-up.  I ended up modifying a Thump RRR twin bearing pulley to fit my Thump RRR tensioner arm and have not had a squeak or any issues since I installed this pulley.  Although the tensioner pulley was not flanged, I believe Thumper RRR has one now, or were in the process of making one last tome I talked to them.

Edited by springer, 09 July 2012 - 07:34 PM.

[ShelbyDW]

Yes and thanks. I had put about 1000 miles on the Whipple supplied 100mm pulley and had no issues. Once it got to a 100 Degrees here in Austin the belt must have streched and it rolled off the back of the whipple 100mm pulley. That's when I went ahead and ordered the Thump flanged dual bearing 100mm because I noticed the play/wobble in the whipple pulley. I was just curious as to what caused the fit issue and hence the rest of the info above was discovered. The Thump 100mm did indead fix the problem and I added the new whipple step washer on the 90mm on the passenger side to avoid any issues with that one just in case.

The information is just for some Whipple owners that think they might have the same problem and can quickly check the 100mm for fit issues before the belt gets shredded.

Edited by ShelbyDW, 10 July 2012 - 04:38 PM.

[springer]

I don't think you had belt stretch issues after 100 miles.  The tensioners will take-up the millimeters in stretch that the belt will eventually  have.

My guess is if the belt came off the back of the 100 idler pulley because the belt wasn't centered very well on this pulley and when you put your foot to the floor, the belt walked-off the backside of the pulley.  With the flanged 100mm pulley,  the belt is centered better on the pulley as well as the addition of the flanges to keep the belt from flying off the backside under load.  Sounds like you had the same problem I had.   Glad the pulley worked for you.

Edited by springer, 10 July 2012 - 07:39 PM.