Tensioner pulley option

[secondchance]

Believe it or not, I cannot remember whether OEM tensioner pulleys on my 91 and 94 were plastic or painted steel.
Either way, our recent options for tensioner pulley has been either cheap looking plastic or billet aluminum sold as "for 5.0 Mustang".
While surfing eBay to kill boredom of being stuck inside, I ran into black powder coated steel pulley advertised as being for Range Rovers.
I got curios and for $12.98, I gave it a shot.

https://live.staticflickr.com/65535/...88fe9431_z.jpg

Well. it looks like it would work just fine. Same diameter as plastic pulley and eye-balling tells me the same offset.

I have not tried it on the car so if you decide to try, it's at your risk.

https://www.ebay.com/itm/New-Lower-A...72.m2749.l2649

[HAWAIIZR-1]

Thank for sharing Yun! That looks promising and like a good option that would work for sure.


Sent from my iPhone using ZR-1 Net Registry

[Dynomite]

Originally Posted by secondchance

I ran into black powder coated steel pulley advertised as being for Range Rovers.
I got curios and for $12.98, I gave it a shot.

Where does it say it is steel and powder coated?

https://www.ebay.com/itm/New-Lower-A...72.m2749.l2649

Manufacturer Part Number:
PQR500350

When I search that Part Number it is suggested it is Polymer.

[secondchance]

Originally Posted by Dynomite

Where does it say it is steel and powder coated?

https://www.ebay.com/itm/New-Lower-A...72.m2749.l2649

Manufacturer Part Number:
PQR500350

When I search that Part Number it is suggested it is Polymer.

I bought one since it looked like steel and it is.

[Dynomite]

Originally Posted by secondchance

I bought one since it looked like steel and it is.

I found on Ebay several of those pulleys (Manufacturer Part Number: PQR500350) that say "Polymer" and one that actually says "steel"....and several that warranty for 50,000 miles (I assume the bearing).

I recall only three Tensioner Pulleys on this Forum that failed and for one of those actually the bearing froze and the belt cut through the Polymer of the pulley. The other two (Polymer and Aluminum) may have been caused by failed bearing also or actually wore from the belt which I can only attribute to the belt flexing as it moves around the curvature of the pulley. The failure of the aluminum pulley cited above appears more like a bearing failure also. I have several aluminum pulleys and several original "polymer" pulleys that do show wear on the belt riding surface.

The smooth outside of the belt compressing as the belt is flexed around the smooth surface of the pulley. At 7,000 rpm this happens at more than 250 times a second for the tensioner pulley. The other possibility is revving the engine in neutral from 800 rpm to 7,000 rpm whereas the Belt Tensioner Pulley cannot angular accelerate that fast within a second or two. Actually the Pulley revs from 1,600 rpm to 14,000 rpm as it is half the diameter of the Harmonic Balancer.

The other smooth aluminum pulley (water pump which is also aluminum in my case) does not wear. That pulley is powder coated and twice the diameter of the belt tensioner pulley. Powder coatings offer a part greater protection from scratches, chipping, abrasions, corrosion, fading, and general wear which may explain the lack of wear on powder coated aluminum pulleys.

[Jagdpanzer]

Steel
IMG_1147.JPG


Sent from my iPhone using ZR-1 Net Registry

[secondchance]

Ok. ?The old magnet trick!? says agent 86.

[Dynomite]

This Powder Coated Steel Tensioner Pulley is beautiful



This Tensioner Pulley would last a Very Long Time as it is Powder Coated, Steel, and Exact size as Original as secondchance suggests.

This Tensioner Pulley is on Ebay from a different Vendor but appears to be identical to what secondchance bought and identical in dimensions to the original Belt Tensioner Pulley

Thank you secondchance.......I Like it (It matches my Black Powder Coated water Pump and Power Steering Pulleys)

Just in case a New Belt Tensioner is required........
New Belt Tensioner

Note secondchance: I will install the Powder Coated Steel Pulley with the Boss on the inside.
(your installation appears to have the Boss on the outside near the bolt head)

The Tensioner Pulley Boss is shown on bottom in above image.

I did check several "polymer" original Belt Tensioner Pulleys and they all show wear similar to the wear of the Belt Riding Surface of the aluminum Belt Tensioner Pulleys.
I would suggest that either the Aluminum or Polymer Pulleys will last 100,000 miles given the wear I see on the riding surface of moderate mileage Polymer or Aluminum Tensioner Pulleys .



The aluminum Pulley on the left has a riding surface wear of about .003" in over 5,000 miles. The Polymer original pulley on the right has more similar wear on the belt riding surface but more miles. The thickness of the belt riding surface of the aluminum Pulley is .106". Assuming a tolerable wear of the belt riding surface of 1/16" the life would be about 100,000 miles for the aluminum Pulley with 1/16" thickness of the riding surface left which should be adequate for structural capability. The same life estimate goes for the original Polymer pulley. The various types of Belt Tensioner Pulleys should be checked for wear periodically as Belts vary in age, texture, flexibility and tension. The Pulley Bearings should also be checked for smoothness of rotation and "play".

Also, this all depends on the Belt slippage with respect to the Belt Tensioner Pulley Riding Surface under rapid rotational acceleration of the engine (Revving) especially in neutral (Going from 800 rpm to 7,000 rpm in a second or two for example). The Belt Tensioner Pulley is probably spinning at twice that rpm given it is half the diameter of the Harmonic Balancer and just cannot angular accelerate that fast from 1,600 rpm (Idle) to 14,000 rpm in under two seconds. The Belt may actually slacken a bit between the Harmonic Balancer and Alternator during hard revving.

The three Belt Tensioner Pulley failures known appear to be the result of a failure of the Belt Tensioner Pulley Bearing

The Steel Powder Coated Tensioner Pulleys should show NO wear on the belt riding surface of the Pulley over time simply because they are Powder Coated on Steel.. The greater weight of the Steel Tensioner Pulleys will result in greater Belt slippage on the riding surface of the pulley during rapid changes in engine rpm (revs in neutral) due to greater resistance to angular acceleration.



You will notice only the Water pump Pulley and Belt Tensioner Pulley rides on the back smooth side of the belt. The Water Pump Pulley has almost a complete Belt Wrap while the Belt Tensioner Pulley has almost no wrap at all. This leads to the assumption that there is potential for much greater slippage during high REVS in Neutral of the Belt Tesnioner Pulley. You may also notice the gap between the two insides of the Belt (opposite the Belt Tensioner) on this Crate Engine which indicates considerable Belt Tension. This is unlike some where the gap is less than an inch indicating a rather loose Belt which would slip more during High Revs.

Mikey suggests all of this discussion is probably moot given the Belt Tensioner, Belt, and Belt Tensioner Pulley should probably be reconditioned between 50,000 and 100,000 miles to avoid having to carry spare Belts and Pulleys

I did install one Powder Coated Steel Belt Tensioner Pulley today and will be interesting how the Powder Coating stands up with use.

I also checked several original "Polymer" Belt Tensioner Pulley Bearings (Average 50,000-70,000 miles) and found a couple that were a bit rough when turning indicating a bearing needing replacement. Most Pulleys do allow for replacement of the bearing only.

[HAWAIIZR-1]

Originally Posted by Dynomite

This Powder Coated Steel Tensioner Pulley is beautiful







This Tensioner Pulley would last a Very Long Time as it is Powder Coated, Steel, and Exact size as Original as secondchance suggests



This Tensioner Pulley is on Ebay from a different Vendor but must be identical to what secondchance bought also.....



Thank you secondchance.......I Like it (It matches my Black Powder Coated water Pump and Power Steering Pulleys)



Note secondchance: I will install the Powder Coated Steel Pulley with the Boss on the inside.

(your installation appears to have the Boss on the outside near the bolt head)



The Tensioner Pulley Boss is shown on bottom in above image.



I did check several "polymer" original Belt Tensioner Pulleys and they all show wear exactly like the aluminum Belt Tensioner Pulleys on the Belt riding surface of the Pulley. I would suggest that either the Aluminum or Polymer Pulleys will last well over 100,000 miles given the wear I see on the riding surface of moderate mileage Polymer or Aluminum Tensioner Pulleys . The three Belt Tensioner Pulley failures known appear to be the result of a failed Pulley Bearing





The Steel Powder Coated Tensioner Pulleys should show NO wear on the belt riding surface of the Pulley over time simply because they are Powder Coated on Steel.

Thanks Mikey! I mean Cliff! [emoji38] I already changed my pulley to the aluminum one a few years ago. Thanks for your evaluation and test of this option.


Sent from my iPhone using ZR-1 Net Registry

[Erik]

Originally Posted by HAWAIIZR-1

Thanks Mikey! I mean Cliff! [emoji38] I already changed my pulley to the aluminum one a few years ago. Thanks for your evaluation and test of this option.


Sent from my iPhone using ZR-1 Net Registry

Which one is the aluminum one?