Good day,


I'm looking for a double sided supercharger belt to fit my 1999 XJR with upper and lower SC pulley upgrades and the updated idler pulley and tensioner. It seems what I need is the updated Jaguar part or aftermarket W0133-1800567 but 2.2 inches longer. Anyone know a good way to decode lengths and find the correct size?


Perhaps a stretch racing belt? x-D


Any help is greatly appreciated.


Thank you!

 

Double sided? Are you speaking of ribbed on both sides, I've never seen that? I'm guessing you did the upgrades and now need the belt?
You should have a part number on your belt somewhere for reference for initial length and width (most folks forget the width, ultra important). I'm replacing mine on my 2000 and the part number is still there and its original. My issue was finding that supercharger belt (NCC7740AE, 51.58 inches), I finally got one on eBay. Some vendors list the lengths there and they list alternate part numbers for reference. As a matter of fact, if you can find it on Amazon, they almost always list the length and widths for their items.
As for the extra length you speak of, I had to do this with my Corvette and the underdrive pulley's I put on. I went to a parts store (Autozone in my case) they pulled out the original spec then began finding matching ribs and measuring until we found one. Tedious but welcome to custom. A local shop may make them also, check with a speed shop.

 

Not sure who made your pulleys, but when we do a lower pulley on any 4.0/4.2/5.0 we convert it to a single sided s/c belt. The double sided belts are not used much and do not come in that many different sizes.


Mike

 

I've researched this for long enough that my OP sounds retarded. Racing "stretch" belts are self tensioning and not designed to work with tensioners from what I've found. I'm fairly certain as Mike has stated that a belt meeting my specs does not exist. I did find 6 and 7 ribbed belts in the correct width and length, but not 8. Thought maybe I could alter the pulley's to work with a 7 ribbed belt, but someone told me that wouldn't work.

I'd also rather not return to the original tensioner and idler pulley as I'd have to change from the updated Jaguar version. Unless there was a mechanical advantage, I'd rather source a belt.

I will look into a custom fabricator and report back.

Thank you!

 

perhaps you could change to a larger diameter idler or tensioner
pulley to increase the run length. that will not change the drive
ratio, but will increase the overall required belt length.

There'll be some arithmetic involved to solve the required diameter
without resorting to trial and error

 

That's a thought however the jump in size is pretty big from what's available if my memory serves me correctly. I'll just use two 4 ribbed belts and call it a day, lol.

 

So I'm going to go ahead and order a dual sided belt 10mm smaller than the specification I need and see if I can make it fit.

What I'm trying: Continental ContiTech® D4080534 - Gatorback? Poly-V Dual-Side Serpentine Belt
Part numbers(the internet is never wrong): D4080534, 8DPK1355, JAGUAR C2C37055.

Likely part number for what I want that does not exist: D4080537 or 8DPK1365.

I'll let you know if it works out.

 

7 rib belt on 8 rib pulleys will be fine. I run some mismatched pulleys on my 4.0/4.2 and they are fine.

 

I'll go with this if I can't get the shorter belt to work. It doesn't seem like a custom v-belt fabricator is going to be interested in a one-off order, though there is a place in the UK that seems to advertise they'd do it,...

One step at a time. The belt arrives Saturday.

 

I confirmed that 8DPK1355 aka D4080534 worked for my situation.


If you have a Supercharger pulley upgrade requiring the longer v-belt 8PK1365, don't be afraid to change the tensioner and idler pulleys to Jaguars updated double sided version.


You should be able to use a this slightly shorter belt just fine.

Thank you all for you comments!


-Erick

 

Hello Erick,

I'm wondering if you have an update on your serpentine belt. I have the Eurotoys pulley update and upon attempting to update the water pump etc tensioners the newer style belt didn't fit -- I'm assuming the same problem you were having.

I didn't update the upper pulley though, wondering is that would make a difference.

JJ

 

My belt is working out great so far. 8DPK1355 aka D4080534 works with my set-up. I'm not sure on what length you need. I didn't use Euro-toys, but I'd check with them on your situation.

Standard 4.0 length should be the 1310mm or 51.57 inches. My setup required a length of 1365mm or 53.74 inches. Unfortunately, there were no double sided belts in that size so the closest thing I could find was 1355mm and it works fine.


This site is fairly useful to see what sizes are readily available:
Poly-V® Belts with Quiet Channel Technology? | Continental ContiTech

 

Please let us know how your situation panned out! Also, I had a scare recently regarding this topic. My belt starting riding forward on the lower pulley recently and I thought I had a fit problem. Switched back to the single sided belt setup and thought everything was fine until my Taper Collet (cone) that connects to the crankshaft cracked and deadlined my Jag. Wasn't sure what the problem was at first, but it's safe to say that the Damper Bolt needs some Loctite,... am I right?

 

That cone shaped piece has 1 split in it normally. The crankshaft bolt comes with loc-tite already on the bolt (new from Jaguar) and as long as it is torqued properly it "will not" come loose.


Get a new bolt (blow out threads with air), look at the pulley hub including the o-ring groove on the inside of the hub and the front seal for damage.


Mike