O-Rings... lots of O-Rings

[Scud]

I'm tired of buying one O-ring at a time and the associated hassle of finding the correct one. So I am hoping to stock up and save... and more importantly have them on hand when needed.

As I understand it, Nitrile is most commonly used, but it degrades quickly, which is why many of have replaced the timing sensor o-ring on multiple occasions, and why we constantly lose the little bugger that serves as a brake pedal bumper.

And Viton is a brand name, while FKM is the generic name for material used in Viton O-rings. And apparently FKM lasts longer in chemicals and sunlight. This is what I think I know, so please feel free to correct me.

I'm looking at this set of 386 O-rings in 30 Metric sizes. Amazon link here. Does this seem like it would cover the majority of O-ring needs for our V11s? Any other recommended sets or sources that would be better?

[p6x]

 

[p6x]

@Scud

The size is normalized. Parker is an o'ring supplier from which we got all our o'rings.

There are different Nitriles strength. Viton is more resilient to temperature.

Here's a link to the Parker website which will ultimately help you finding whatever o'ring you need:

http://solutions.parker.com/ORingSelector

 

[Scud]

Wow - should be able to find anything there... but I was kind of hoping that most O-rings on the bike would be a standard size and that I could order an assortment and be likely to have whatever sizes I would need in future. Do you think that's realistic? 

But there is one very thin O-ring I would like to find - the one that seals the two halves of the driveshaft. Parker looks like a promising supplier.

[docc]

21 minutes ago, Scud said:

Wow - should be able to find anything there... but I was kind of hoping that most O-rings on the bike would be a standard size and that I could order an assortment and be likely to have whatever sizes I would need in future. Do you think that's realistic? 

But there is one very thin O-ring I would like to find - the one that seals the two halves of the driveshaft. Parker looks like a promising supplier.

Very interesting. The Parts Catalog only shows the driveshaft as an assembly. While we have derived the U-joints and the angled Zerk fittings, that O-ring has yet to be divined . . . 

 . . . more V11 mystery for the dark wizards of our alchemy  . . .   

[Lucky Phil]

3 hours ago, Scud said:

I'm tired of buying one O-ring at a time and the associated hassle of finding the correct one. So I am hoping to stock up and save... and more importantly have them on hand when needed.

As I understand it, Nitrile is most commonly used, but it degrades quickly, which is why many of have replaced the timing sensor o-ring on multiple occasions, and why we constantly lose the little bugger that serves as a brake pedal bumper.

And Viton is a brand name, while FKM is the generic name for material used in Viton O-rings. And apparently FKM lasts longer in chemicals and sunlight. This is what I think I know, so please feel free to correct me.

I'm looking at this set of 386 O-rings in 30 Metric sizes. Amazon link here. Does this seem like it would cover the majority of O-ring needs for our V11s? Any other recommended sets or sources that would be better?

Viton and FKM orings have there place, so are excellent in gasoline and withstand high temps up to 200 dec C fine however they have inferior cold weather performance compared to Nitrile. Nitrile are fine for most things not engine related. Be also aware that components designed for nitrile orings can't always accept FKM due to slight sizing differences between the 2. A small dimensional difference on the oring groove makes can make the difference between fitting and not useable. The manual fuel tap issue is a case in point, there was no FKM size that would translate to the standard fuel tap piston nitrile oring grooves and the grooves needed to be modified a little to take the FKM seals. 

Ciao  

[p6x]

11 hours ago, Scud said:

Wow - should be able to find anything there... but I was kind of hoping that most O-rings on the bike would be a standard size and that I could order an assortment and be likely to have whatever sizes I would need in future. Do you think that's realistic? 

But there is one very thin O-ring I would like to find - the one that seals the two halves of the driveshaft. Parker looks like a promising supplier.

Let's work with an example;

When you change the oil filter on a V11, lets take the oil filter access cover oring.

I have that oring on hand, so I can measure it with my vernier caliper;

The o'ring cross-section is 3.5mm; which correspond to 3.53mm from the table.

Measuring the ID is a bit more difficult, but it is around 95mm; the closest I get is 94.84mm from the table.

It corresponds to Parker size 2-240. On a funny note, if I was still in my company, I could use a B-17308 o'ring; which is the reference my company gave to that o'ring size, for our application. Most likely a Viton o'ring because our tools are submitted to high pressures. Nitrile would deform and leak.

Let's go to the Parker site; for this o'ring size; I select Nitrile and 70 durometer; the cheapest. Since this o'ring is just sealing one direction and temperature is below 250F, I would not need Viton. I have ran oil field tools in oil wells for 35 years, and changing o'rings after each run.

That oring costs 3.64 USD at MG-Cycle currently.

So the biggest job, is to find the size of the o'rings you want to stock. Use the Parker sizing tool which is easier than my tables. We had those tables back then, because we did not always have maintenance manuals, so we had to find o'rings using cross references and/or sizes.

 

[Scud]

Quite the education on O-rings. And I know that in high-reliability environments (mining, aviation, etc.), a mistake can be costly or deadly (Space Shuttle Challenger explosion).

But for hobbyist like me, seems that just ordering from MG Cycle or Harpers is the solution. That said, I accept the challenge of finding the correct O-ring for the driveshaft. I have a spare with a broken O-ring, so will order all the O-rings that are close to its size and see what works. Seems like Nitrile would be fine for that application, FKM might last longer.

[p6x]

14 minutes ago, Scud said:

Quite the education on O-rings. And I know that in high-reliability environments (mining, aviation, etc.), a mistake can be costly or deadly (Space Shuttle Challenger explosion).

But for hobbyist like me, seems that just ordering from MG Cycle or Harpers is the solution. That said, I accept the challenge of finding the correct O-ring for the driveshaft. I have a spare with a broken O-ring, so will order all the O-rings that are close to its size and see what works. Seems like Nitrile would be fine for that application, FKM might last longer.

O'ring have played a big part in my professional career. We should call them by their real name: tore joints. 

I remember the space shuttle catastrophe. Cold make o'rings brittle.

I would go Nitrile 70 or 80 if really pushed.

I was surprised to see the price from Parker. I was expecting something in cents, not 2+ dollars. We could make a table with the size of the mostly used Guzzi o'rings. The oil filter cover one can justify a purchase of 6.

I would never reuse an o'ring. I systematically replace them. Not worth the saving. Even if the o'ring looks ok, the temperature changes affect the molecular integrity. I had a leak at that very oil filter cover on my Le Mans.

[MartyNZ]

I have a couple of boxes of nitrile o-rings, but no matter what, I still have to go out to the local seal shop for a specific size that I don't have.

I stopped being so picky about buying OEM o-rings after a visit to Moto International in Seattle USA. I asked for seals on the fuel injectors. The parts guy grabbed an old injector from their workshop, then pulled the right size seals from an assortment box.

Then I realized that Moto Guzzi would use standard sizes where possible to keep the costs down.

As for FKM, yes it can be better (but more expensive) in some applications, but since I see nitrile lasting 20 years, a new nitrile seal should last another 20 years. 

[po18guy]

Don't know if this helps, but there is an O-ring specialist in the Czech Republic (Bohemia Seal). They stock an amazing variety of sizes and materials in O-rings and all manner of seals. They sell primarily on eBay. They came to my rescue when I needed a very specific O-ring for a SRAM 9.0 rear derailleur I was modifying.  https://www.ebay.com/str/bohemiasealoring/O-ring-inner-dia-from-10-to-20/_i.html?store_cat=25950217018

[Scud]

6 hours ago, MartyNZ said:

I have a couple of boxes of nitrile o-rings, but no matter what, I still have to go out to the local seal shop for a specific size that I don't have.

This is exactly what I wanted to avoid - buying a box of assorted for convenience, and not being able to actually use them.

[leroysch]

I've given up trying to be O-ring efficient and started an O-ring parts bin..right next to the bin containing a myriad of Cu sealing washers. First addition...99 #112'S of the Viton persuasion. Those of unknown pedigree I use in place of those plastic washers generally used where bodywork is involved. Keeping track of those things is worse than trying to find a 10mm socket.....

[Lucky Phil]

10 hours ago, p6x said:

Let's work with an example;

When you change the oil filter on a V11, lets take the oil filter access cover oring.

I have that oring on hand, so I can measure it with my vernier caliper;

The o'ring cross-section is 3.5mm; which correspond to 3.53mm from the table.

Measuring the ID is a bit more difficult, but it is around 95mm; the closest I get is 94.84mm from the table.

It corresponds to Parker size 2-240. On a funny note, if I was still in my company, I could use a B-17308 o'ring; which is the reference my company gave to that o'ring size, for our application. Most likely a Viton o'ring because our tools are submitted to high pressures. Nitrile would deform and leak.

Let's go to the Parker site; for this o'ring size; I select Nitrile and 70 durometer; the cheapest. Since this o'ring is just sealing one direction and temperature is below 250F, I would not need Viton. I have ran oil field tools in oil wells for 35 years, and changing o'rings after each run.

That oring costs 3.64 USD at MG-Cycle currently.

So the biggest job, is to find the size of the o'rings you want to stock. Use the Parker sizing tool which is easier than my tables. We had those tables back then, because we did not always have maintenance manuals, so we had to find o'rings using cross references and/or sizes.

 

Hold on here, 250F is 121C and some BB engines can see 140 deg C bulk oil temp under some conditions and 100 deg C is common. Nitrile is good to around 100 deg C which is ok for an easy to replace oring like this or on the filter where it's going to be replaced regularly but just about everywhere on an engine a Nitrile oring is at it's limit. This is why Guzzi have been slowly phasing them out for FKM seals which Ducati did years ago as well.

Ciao

[docc]

Makes me think I should replace my original filter cover O-ring with something . . . .  maybe even pretty soon (next filter change)?