Dinan supercharger belt tensioner

[creek]

Just leaving this here to update a really old thread. I recently acquired a nice 2004 M3 with some Dinan upgrades and was looking for a replacement tensioner that was not $250. So what I have found so far is that the dinan tensioner uses off the shelf dayco parts. The only difficulty is finding them as a single unit. The pulley is a Dayco 89005. This is very similar to the original but the bearings are a bit bigger now (NTN 6303LU now vs NTN 6203LH in the original. Inside bearing diameter is the same outside is slightly larger, but the pulley diameter and width are identical). I haven't been able to find this pulley mounted to a tensioner yet but the one I got from Autozone is nearly identical. I hope to find some concrete source for this in a day or two. I have attached some pictures of the original pulley and the tensioner bodies for reference.
2016-06-28 12.24.36.jpg

[creek]

A couple more pics since I hit my limit on the first post.

[MisterM52]

Thanks for posting, it would surely help many, I must ask, is it that important for you to retain the stock pulley size, I get the whole OEM/Dinan thing, but can you go a few mm up or down, the belt should adjust itself and if not you can always use it as a excuse to use a smaller or larger belt?

[geargrinder]

I have no doubt it's an off the shelf tensioner. Might help to think of it as not a "dayco" only but realize it's probably some interchangeable part and likely theres a Gates version too and who knows what.

I did same routine w our M62 VF kits , pretty quickly found it was some GM LSx tensioner that is available on the shelf at every auto parts store in America for $30. VF do swap the pulley for a sweet stainless one so I just press a new standard bearing into that and then put that into a new auto part store tensioner.

Be ready though dayco and gates have hundreds of tensioners all just a little different. It's "fun" to wade through them...

- - - Updated - - -

BTW agree w Mister you may have oppty to use slightly difft pulley / belt combo and have it be perfectly fine too. Depending.

[busterhax]

I was able to find my e36 dinan dayco pulley at autozone for around $10-15. The numbers on the pulley didn't help at all. I had to cross reference. Yours may be Dayco 89104

No. of Bearings	2
Flange	N
Bearing ID 1 (mm)	17
Pulley Material	Polymer
Pulley Type	Serpentine
Flat	Y
Max Belt Width	08 Rib
Pulley Diameter (mm)	78
Pulley Width (mm)	32.80

[Braymond141]

Gates Belt Tensioner Pulley (36094)

[bubbafett]

Ok so who is correct here? There is three answers above. lol

[geargrinder]

Ok so who is correct here? There is three answers above. lol

Clearly its not a "there is one answer" question.

realize it's probably some interchangeable part and likely theres a Gates version too and who knows what.

The Gates and 2 Dayco numbers above are essentially same pulley. The Gates is a 1/2mm narrower than the other two. The 2 Daycos are only .2mm width diff from each other. Prob doesn't matter. No surprise 3 different guys found 3 different PN's that work fine. There's probably at least a half dozen more each of Gates/Dayco that work.

[bubbafett]

Thanks Geargrinder, good to know. Any idea what gates tensioner was used above as well?

[geargrinder]

As I said above, I'm 100% certain it's some off the shelf part that probably fits a GM or Ford product, but you'll have to comb through listings to figure it out if nobody else has so far.

That's more or less what we did for our kits but I can't help w/ a Dinan E36 setups... I would say that flat wide spring suggests more Dayco to me than Gates but who knows. Comb through google image pix for Dayco and Gates tensioners and see if you see something, but its a little needle in a haystack... there's zillions of those things...

[bubbafett]

DAYCO 89202, is what another thread listed. Hope this helps someone in the future.

[philly98540]

Once you have to Dayco part number, you can cross reference to find the equivalent Gates model. For my and GG's application the Gates is superior. May be better for your application too?

[sagggas]

Hey everyone,
Keeping this thread alive. I'm running a Dinan SC kit on my Z3M (S52) and it's been 'upgraded' by RMS with aftercooler, 8 rib, more boost, etc.

I checked the image of my dinan tensioner against Creek's at the top, and the numbers on his image are very close to mine. My pulley is a bit fancier than the original, but the tensioner has not changed. It's been going out for a while, but I had the opportunity to remove it a couple years ago when the bearing's failed and it seized sending a spray of belt rubber all over the engine bay (during an HPDE of course).

Anyway, the images of the Dayco part (89202) that bubbafett mentioned looked real nice and similar. My tensioner's been getting softer ever since...

After a bit more digging, I found a Duralast part (305202) that also looks identical. The 'equivalent' Gates part didn't look close enough for me to buy and try.

[1000hp]

I switch to this pulley on my car, due to not being able to find a belt that I could get over the original Dinan-spec pulley which would not stretch to the bejesus and end up rubbing on itself on the other side.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This pulley allows me to run a shorter belt, which allows plenty of room to stretch over time.

[Braymond141]

The standard Dinan parts are

Tensioner; Dayco 89202 the included pulley is not used.
Pulley; Gates 36094

You don’t need a smaller tensioner pulley with the right belt combo.

Saggas, you are running an RMS pulley. The bearings are replaceable. You need two Nachi 6203 bearings.

6203-2NSE Nachi Bearing 17x40x12 Sealed C3 Japan Ball Bearings https://www.amazon.com/dp/B0045E0E8U..._TfYUAbG7RN1FH

[Randy Forbes]

I switch to this pulley on my car, due to not being able to find a belt that I could get over the original Dinan-spec pulley which would not stretch to the bejesus and end up rubbing on itself on the other side.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This pulley allows me to run a shorter belt, which allows plenty of room to stretch over time.

Another consequence of running that oh so tight belt is that you can burn the mains; top of #1 and bottom of #2 (crank flex much...).

[sagggas]

Hey Everyone,

Thanks for the help.

@Braymond, do you know if there is any difference between various bearings? For example, this PGN bearing is rated at a higher RPM (20K vs. 12K):

https://www.amazon.com/gp/product/B0...MAP3U4RK&psc=1

Not sure if it US or Chinese made.

@Randy, that was me you spoke to the other day (I'm sure you already figured that out).
Thanks,
Sean

[Randy Forbes]

Hey Everyone,

Thanks for the help.

@Braymond, do you know if there is any difference between various bearings? For example, this PGN bearing is rated at a higher RPM (20K vs. 12K):

https://www.amazon.com/gp/product/B0...MAP3U4RK&psc=1

Not sure if it US or Chinese made.

@Randy, that was me you spoke to the other day (I'm sure you already figured that out).
Thanks,
Sean

Yep Glad you're getting the support you needed!

[sagggas]

So the drama continues. Spend a good portion of Saturday removing the old tensioner and attempting to reinstall. Should be simple right?

Nope.

First problem. Looks like RMS (or possibly Dinan from 11 years ago) shaved down the pulley mount. Not a huge deal, but I don't have that kind of grinder (managed to get it done, but took more time than it should):

DSC_0416 (2018-03-31T10_33_54.000).jpg

Grinded... Ground? whatever.

Why is the pulley bolt a different size? Remember my pics from the 26Mar post above? Not sure if you can tell, but that catastrophic failure also torqued the pulley to the side - which is probably why RMS bored a larger bolt hole when they repaired it a little over two years ago. What they did not do, and why I now realize it has squeaked since then is re-spec the bearings (which for some reason fit a little bit loose now). When the pulley torqued a while back, the pulley (nice soft aluminum) was jammed or forced to spin against the outer bearing edge (stainless) and the bearing seat size increased. We didn't measure it, nor could we machine it clean. Assuming the new size is ~40.5-41mm instead of the old 40mm. So now the bearings wiggle a bit (assuming they've been wiggling for 2 years which is why the bearings are wearing out so fast - belt too as the pulley is resonating on the belt.

DSC_0415 (2018-03-31T10_33_42.000)_2.JPG

What to do... Let's spot weld a bit onto the sides of the bearings so the stay in place when pressed. It worked. Its not perfect as I can feel a bit of resistance on about 1/6 of the bearing's rotation. I need a new one anyway, so this will do for a while.

We put it all back together and turns out my new belt is too long (my fault by apparently not being able to read a chart). For my application, I need a belt with spec of 8PK1415 (the 1400 is too short and the 1425) is too long. The only manufacturer I found that makes this length is Gates, but its in their standard line. They have an RPM line which is supposed to be stronger, but they only have the 1400 and 1425. Does anyone know if another manufacturer makes an 8 rib in the 1415 length? I have 2 Gates on the way, but would like to know it will last longer than a year.

Thanks,
Sean

[Braymond141]

That would be the handiwork of RMS.

[1000hp]

You don’t need a smaller tensioner pulley with the right belt combo.

Some of my mounting bracket stuff has been modified (professionally, by a machine shop) to allow me to run a Vortech S/C with parts of a Dinan bracket kit which was originally intended for a Powerdyne S/C (the main "plate" is a new Vortech plate sourced from Dinan). This may be why the Dinan spec'd belt didn't fit properly with the original pulley. BUT, I have seen others post here with a complete original Dinan kit, with the specified belt and the pulley that comes with the kit, and their belt stretched to the point where it was about 1mm from rubbing against itself. I now have about 1" between the two sides of the belt thanks to the smaller pulley and shorter belt.

Another consequence of running that oh so tight belt is that you can burn the mains; top of #1 and bottom of #2 (crank flex much...).

My belt is not oh-so-tight. The tension on the belt itself is no higher than with the Dinan-spec'd belt and pulley. It is a sprung tensioner, which is now not as far into its stroke (but not maxed-out in either direction) due to the shorter belt. It's not putting any more tension on the belt with the shorter belt and smaller pulley.

[ppapadidio]

/I'm from the future/ and glad I finally found this thread as I too have a Dinan Supercharger.

I've got a Dinan 7 and am in need of a replacement Supercharger Tensioner and pulley (bearings are not turning freely - just a matter of time)

Dinan wants $249 for it and they say they have 4 of them left. But I can't imagine paying that.

Does anyone have an inkling as to if the tensioners are similar depending on model of car?


I'll have to get the measurements of the pulley and detailed pictures of the arm and post for comparison but in the interim:
Supercharger tensioner arm.jpg
Here are the belts that fit my setup:

Super Charger Belt
NAPA Micro V AT 25-060594
Belt Poly K 60.25in OC 6 Rib


GATES 060594
Number of Ribs 6
Outside Circumference (in) 59.968

Hey everyone,
Keeping this thread alive. I'm running a Dinan SC kit on my Z3M (S52) and it's been 'upgraded' by RMS with aftercooler, 8 rib, more boost, etc.

I checked the image of my dinan tensioner against Creek's at the top, and the numbers on his image are very close to mine. My pulley is a bit fancier than the original, but the tensioner has not changed. It's been going out for a while, but I had the opportunity to remove it a couple years ago when the bearing's failed and it seized sending a spray of belt rubber all over the engine bay (during an HPDE of course).

Anyway, the images of the Dayco part (89202) that bubbafett mentioned looked real nice and similar. My tensioner's been getting softer ever since...

After a bit more digging, I found a Duralast part (305202) that also looks identical. The 'equivalent' Gates part didn't look close enough for me to buy and try.

[540-S3]

When you disassemble your setup be sure to note all washers and offsets between the pulley and tensioner. Also the pulley bolt is reverse thread.

For my 540 setup here is what I recorded.
SC Dayco idler pulley - 89005
SC Dayco tensioner - 89201

[540-S3]

I also had my SC pulley coated by these guys. Works awesome.

http://www.carbiniteracing.com/pulley/pulley.html

[sagggas]

/I'm from the future/ and glad I finally found this thread as I too have a Dinan Supercharger.

I've got a Dinan 7 and am in need of a replacement Supercharger Tensioner and pulley (bearings are not turning freely - just a matter of time)

Dinan wants $249 for it and they say they have 4 of them left. But I can't imagine paying that.

Does anyone have an inkling as to if the tensioners are similar depending on model of car?


I'll have to get the measurements of the pulley and detailed pictures of the arm and post for comparison but in the interim:
Supercharger tensioner arm.jpg
Here are the belts that fit my setup:

Super Charger Belt
NAPA Micro V AT 25-060594
Belt Poly K 60.25in OC 6 Rib


GATES 060594
Number of Ribs 6
Outside Circumference (in) 59.968

Hey, I can't tell from the pic, but your tensioner looks identical to the E36/M Coupe tensioner we have listed above:
Dayco part (89202)
Duralast part (305202) (Autozone)

You should be able to pick it up for $35-$45

If you look at the back of your tensioner, see if '202' is inscribed somewhere. Its in both part numbers I listed and also in my first pic from my 26Mar post. The pulley will likely need to be replaced, but I'm certain you can find something similar at your local parts store - bring the old setup with you and they'll help you find what you need... I had to go back and forth over a couple of days for various pulley and belts to arrive. The pulley should cost anywhere from $16-$65 depending on material and quality of bearing. Also someone above mentioned the tensioner to pulley bolt was reverse thread. They Duralast one I picked up was regular thread.

For everyone else, I ended up needing a new custom pulley as the 3ish inch one from RMS immediately stretched the new belt so that it touched itself - no not like the song. My buddy has a mill and lathe in his garage, so we spend 8 hours designing and building a 2.1" pulley using the 6203 spec bearings mentioned previously. I'm also back to an 8PK1400 belt and have about 3/4" of space between the sides of the belt (Its really tight, so I'm forced to push it onto the top of the SC pulley and then use a wrench to turn the pulley until it seats all the way - def not ideal, but serviceable). Your application is different, though and I can't help you with the length. It should start with 6PK... Good luck - perhaps your current belt will last a bit longer?