6203 Hybrid Ceramic Bearings

Can you post a link to the operating specs (or the page you posted)?

PS You have "full complement" selected, but don't think that would be good/appropriate for this application (too much ball-to-ball friction and the higher load capacity not needed).

 

Oh, wow! Some good detective work here!

The only experience that I can add to any ceramic pros-and-cons discussion is to note that, in the early water cooled Porsche world, ceramic bearings are all of the rage when considering an IMS bearing replacement.

Discussion here (note the many references to other websites noted): https://www.pca.org/why-choose-ceramic-ims-bearing

 

Couldn't find any technical data at all on that ortech site, but a comparison of SKF's hybrid 6203 data to SKF's 6203 data doesn't show anything that would be a problem -- the 4th column is the dynamic load rating C (kN), and the 5th column is the static load rating C0 (kN):

SKF hybrid 6203
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SKF 6203 (all steel)
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One minor caution might be that the ceramic balls are so hard that the hybrid bearing won't tolerate "hammering"/ball loading abuse during installation as well as the all steel bearing would so be extra careful there (to not damage/Brinell the steel races).

 

Those load ratings are similar to the NTN 6293 bearings (9.6 dynamic and 4.6 static.) No real advantage if these are the hybrid numbers.

 

Sorry Tommy, I don't know enough about them and the materials used. I thought the load ratings would be a bit better but it could be that the ceramic balls wear much slower and give longer service life. If the experts say they're better for high loads and high temp then the price difference of about $25 is negligible given the work to change them and the cost of failure. I would see if viton (FKM) seals are available as the nitrile seals are only good for 100C and could be the main cause of failure (seals fail, grease escapes.)

 

Yes, those load specs look perfectly reasonable, but the RPM specs are for an ''open" (no sliding seals) 6203 hybrid bearing. No bearing of this size could operate at 28,000 RPM (even for a short while) unless in a temperature-controlled oil bath situation providing the best possible lubrication and the best possible heat transfer. In fact, these specs, and even the terminology used, so exactly matches the SKF data for an open 6203 hybrid bearing that either: 1) they just copied the SKF data for a 6203 open hybrid bearing , or 2) they are affiliated with SKF and their open 6203 hybrid bearing is exactly the same thing as an open SKF 6203 hybrid bearing. Having even the best sliding seals (and contained grease lubrication) would lower the "limiting speed" to something like 12K RPM, but this isn't an issue as the maximum RPM for this bearing as used in the 308 cam drive is about 6000 RPM.

 

The (much) harder ceramic ball actually penalizes the steel races a bit so the dynamic load rating tends to be slightly lower for a hybrid bearing of the same size. The upside comes under unusual conditions, like ball skidding, which tends to harm the ball more than the raceway (so the harder ceramic ball suffers less damage than a steel ball would).

 

The 2RSL seals are NBR. L is for low friction.

 

I had a look for some of the HC5 bearings and only found the 2RSL versions. What versions have you found? edit: just saw that you were talking about Ortech bearings- thought they were an SKF distributor but just looked them up

 

The PEEK seals and 399 °C grease they offer are a real bonus.

 

This current discussion brings to mind a thread of around a year ago which discussed these bearings:

https://www.ferrarichat.com/forum/threads/the-use-of-oversized-lower-cam-outer-bearings.612899/

As can be seen in the above, folks like Brian Crall were of the opinion that the OEM spec bearings were good enough for the job, considering the infrequent usage of these cars today vs. when they were new.

But I most certainly do applaud the idea of trying to find a better ceramic bearing, especially in light of the anecdotal stories of cheap counterfeit SKF bearings flooding the market today.

 

The original ones have lasted 30+ years and (for many folks) over 100k+ miles. What is the 'problem' that needs to be "solved" with ceramic bearings?

 

.. and Ferrari changed to 44mm bearings on later QV engines for a reason.

 

Aha! OK, I was not aware of the problem with the earlier cars/bearings. I had ASSUMED that all 3x8s had the same relevant parts. I was not aware that Ferrari had a problem with the earlier bearings and had changed to a larger one later in production.