Engine Drivetrain 1st Gen Cooper S Most liked posts in thread: Now I Know Why Belt Tensioner Stops Break...

No one can confirm that. You just have to spend $38.80 an find out yourself. :ihih:

I am sure they don't make a specific MINI / Merc dampers they just share the same basic parts except for the cast parts and pulleys.

 

Is it really worth all this effort? The new part is only $93 bucks?

You can buy (3) new tensioners on Amazon for the cost of (1) dealership OEM one.

It just seems like you are trying to reinvent the wheel just to run yourself over with it.

 

So true! The only thing better about DIY is DIY done cheaper than the other guy!:biggrin5:

 

Please help with the feasibility study!

@minsanity (and everyone else), I have begun a tensioner delete feasibility study to see if a stretch-belt can be substituted at a reasonable cost. My intent is to duplicate the tension that the (poorly designed) tensioner assembly creates. But it's going to take some engineering to do it right.

Probably the first question is whether a stretch-belt can be prototyped (and then made in a small batch) without being prohibitively expensive. I am contacting vendors and hoping that will turn up a good option. If not, my uncle retired after a 30 year career with Ford as a mechanical engineer and I expect he can put me in touch with someone who might be able to help in my crusade for an R52/53 stretch-belt.

For prototyping, I can afford a couple hundred bucks probably. But for the actual "kit", my goal is to keep it under $100 since that is about the cost of the OEM belt and tensioner combined. Those are the financial deal-breakers for me.

As for the stretch-belt itself, here's what I know so far:
The drive length needs to be measured. A normal belt has an effective line slightly beyond the circumference of the pulleys. This adds about 10mm to the R52/53 serpentine belt length. But a stretch-belt is about 0.1% smaller in free length (vs. the equivalent normal belt) which means the spec must be 10 to 20mm less for the R52/53 stretch-belt. In other words, it may be that simply measuring the drive length could yield the right spec for a stretch-belt. The generic form for the belt has the same cross-section as a 6PK but WITH elasticity. Tension should be about ~100N per rib => ~600N. (I figure we have about a 20% factor of safety on that to avoid damaging bearings and shafts.)

Reference material -
A) See pages 6, 12, & 13 here:
http://www.optibelt-usa.com/fileadmin/files/Catalogs_and_Manuals/TECH_MANUAL_RIBBED_BELTS.pdf
B) page 23: https://www.contitech.de/pages/produkte/antriebsriemen/antrieb-industrie/download/TD_Multirib_de_en.pdf
C) http://www.veyance.com/ProductsDetail.aspx?id=21071
D) pages 12 & 13 how to asses EPDM stretch-belt wear followed by recommendation to replace tensioner at every belt change!
http://www.gatesaustralia.com.au/~/media/files/gates-au/automotive/catalogues/drive-belt--components-catalogue-aus--nz-november-2009.pdf
E) http://www.gates.com/catalogs-and-resources/resources/repository/engineering-business-applications/design-iq

Concerns include the reduction of about 50% in the belt wrapping on the crank pulley and about 30% on the SC pulley. Study so far indicates that if the stretch-belt will do the job properly (within the tension tolerance) then it will likely wear out faster than the stock belt. I'm ok with changing the belt up to twice as often as before, just to be rid of the tensioner.

I could use some help with this project:
1) more measurement data of the drive path from other Minis
2) support in sharing the prototyping cost (including field testing on other Minis)
3) pledges to purchase the "kit" when (and if) it's ready
4) validation of the goals and calculations

Here's a 10 question survey to make it easy for you all to assist:
https://www.surveymonkey.com/r/66LX5GS
(Privacy/anonymity will be honored.)

Best regards,
Andrew

 

^^ THAT ^^

Plus, the money you have set aside for yourself to reinvent the wheel, could buy a lifetime supply of tensioners and "old fashioned" belts.

 

Still the way to go......

.http://www.motoringalliance.com/forums/redirect-to/?redirect=https%3A%2F%2Fwww.amazon.com%2FACDelco-38404-Professional-Automatic-Tensioner%2Fdp%2FB001KSDZOY%2Fref%3Dsr_1_8%3Fie%3DUTF8%26qid%3D1473687267%26sr%3D8-8%26keywords%3Dbelt%2Bdamper