Wasa cam follower

[Jayz691]

Well, my Wasa Motor cam follower just came today. 4 days to get here(PA, usa) from Sweden, not bad..first impression, it VERY light, made from Silicon nitride. Almost feels like graphite, it's so light. But very strong and smooth.196397196398

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[viperdsa]

Keep us updated with how it does.

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[Jeevan]

Bet it will be cracked into pieces before 20k. There is a reason manufacturers use specific material. If mechanics become engineers, the world would be flat. Update here if possible after 20k miles


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[Jayz691]

Bet it will be cracked into pieces before 20k. There is a reason manufacturers use specific material. If mechanics become engineers, the world would be flat. Update here if possible after 20k miles


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)Well, won't know cuz was advised to remove. Its just metal dude, not some space metal, lol. And they are engineers/machinist, not mechanics, lol.

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[EvolutionArmory]

Who told you not to use it and why?

[Kevin C]

Who told you not to use it and why?

Soma have failed when used with aftermarket pumps. It appears that some pumps use a larger spring that the factory pump and it was causing a catastrophic failure when it bound up on the ID of the follower.

[EvolutionArmory]

I think I told Jay not to bother with this follower in a Facebook group we both belong to. I was just curious why he chose to believe this other person.




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[Kevin C]

I have been following the part because technically its pretty interesting. As a wear surface it should be superior to the oem piece, that includes reducing cam lobe wear. If it breaks.... that's game over. The same material is used in valve trains in HD diesels for the same reasons. Being an early adopter can be expensive.

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-Silicon-Nitride-Fuel-Pump-Rollers/?N=5002385+8745513+3292678282&preselect=8710684+8719591+8722000&rt=rud

[Sylvania A4]

The inherent nature of ceramics is to fail in tension or torsion, which this component really experiences neither. Ceramics are strongest in compression, so unless there are large impurities or the component is poorly manufactured the biggest concern would be premature wear to the cam lobe itself. The SiN is going to be exponentially harder than the cam lobe. Also, the lubricity of the SiN would come to question. These would require significant polishing, and even then the peaks of the crystal structure may just be rounded, not flattened. These materials are better served as a coating because it's easier to control grain orientation on a surficial material than it is the bulk (via sintering).

[Kevin C]

The inherent nature of ceramics is to fail in tension or torsion, which this component really experiences neither. Ceramics are strongest in compression, so unless there are large impurities or the component is poorly manufactured the biggest concern would be premature wear to the cam lobe itself. The SiN is going to be exponentially harder than the cam lobe. Also, the lubricity of the SiN would come to question. These would require significant polishing, and even then the peaks of the crystal structure may just be rounded, not flattened. These materials are better served as a coating because it's easier to control grain orientation on a surficial material than it is the bulk (via sintering).

With regard to tribology I would suggest reading a few research papers on the subject, the consensus is they reduced cam wear significantly. The spring problem on aftermarket pumps was a binding of the OD of the spring on the ID of the follower, that put the part in tension (hoop stress).


Tests were also conducted with metal against metal pairs for comparison. The simulation tests of hot-pressed Si3N4 Ceramic tappet against metal cam pairs were conducted on a single cam-follower test machine. The test results showed that not only that the Si3N4 ceramic has excellent wear resistance, but also that the wear of the metal parts in contact with the Si3N4 ceramic decreased. These results were supported by engine bench test results.

https://asmedigitalcollection.asme.org/tribology/article-abstract/115/2/295/436835/Study-on-Tribology-of-Silicon-Nitride-Ceramic?redirectedFrom=PDF

[EvolutionArmory]

I love this forum. We got some serious smarty pants in this group. [emoji3]


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[Charles.waite]

I think they're referred to as

https://media.giphy.com/media/A9KfKenpqNDfa/giphy.gif

[Sylvania A4]

With regard to tribology I would suggest reading a few research papers on the subject, the consensus is they reduced cam wear significantly. The spring problem on aftermarket pumps was a binding of the OD of the spring on the ID of the follower, that put the part in tension (hoop stress).



https://asmedigitalcollection.asme.org/tribology/article-abstract/115/2/295/436835/Study-on-Tribology-of-Silicon-Nitride-Ceramic?redirectedFrom=PDF

Thanks, the paper your citing effectively states similar expectations, only mine was purely anecdotal from years of other SiN processing, though my focus was primarily AlN and Alumina. HIP (likely then polished) SiN has excellent lubricity, so clearly they've addressed the surface morphology which isn't a surprise given their hypothesis. I don't have direct access to the article, but the sintering temperature and conditions would also be important to understand. Sintering SiN is energy intensive, and the sintering temperature/time will also dictate surface properties and final hardness. The failure occurred in tension, an oversight on my part as I would have expected appropriate clearance of the tappet/spring interface.

[Sylvania A4]

I think they're referred to as

https://media.giphy.com/media/A9KfKenpqNDfa/giphy.gif

Such a terrible, yet great movie series.

[EvolutionArmory]

Who told you not to use it and why?

Jay. Wanna answer?

I think this is just another miracle follower like the ones that were tried a few years ago.

The problem isn’t that the OEM cam follower material is inadequate. It’s that the whole system is inadequate.

You gotta go roller conversion if you want a longer lasting follower that won’t eat up your cam. All these miracle followers do is add hardness to the follower but probably at the expense of your cam.

[canadianA4B7]

I actually collected a bag of these for some hardness testing to be done. The overall outcome was that the actual cost to go to something like a titanium. Or a hardened tool steel that’s been cryo treated then coated is that the materials lack thickness and cannot be made thick enough to reduce the excessive wear at a reasonable cost. Cryo treating them and re coating 100 of these was $1000’s of dollars.

There’s 2 alternate coatings that can also be used The downside is that they’ll “chip” if the contact becomes to blunt. Will it last longer hell yes will it be cost effective, not until we find materials on Mars that are better then on earth.

And lastly design, every shop I spoke with first comment was the unit has holes in that’s going to weaken it. If it were solid the coatings had less small surfaces to adhere too just 1 flat area they’ve all said lifetime would likely double.

Cam roller conversion is the way to go. Keep eyes on classifieds for mine being listed soon.

[Sylvania A4]

I actually collected a bag of these for some hardness testing to be done. The overall outcome was that the actual cost to go to something like a titanium. Or a hardened tool steel that’s been cryo treated then coated is that the materials lack thickness and cannot be made thick enough to reduce the excessive wear at a reasonable cost. Cryo treating them and re coating 100 of these was $1000’s of dollars.

There’s 2 alternate coatings that can also be used The downside is that they’ll “chip” if the contact becomes to blunt. Will it last longer hell yes will it be cost effective, not until we find materials on Mars that are better then on earth.

And lastly design, every shop I spoke with first comment was the unit has holes in that’s going to weaken it. If it were solid the coatings had less small surfaces to adhere too just 1 flat area they’ve all said lifetime would likely double.

Cam roller conversion is the way to go. Keep eyes on classifieds for mine being listed soon.

I recall talking with you about this, and providing a few followers for development. The starting condition of the cam also factors into the wear, same as OEM followers.

[Charles.waite]

I still have one of the chrome plated followers that I think EPY had made. Never used it because I realized I wasn’t interested in being a guinea pig, haha.