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Discussion Starter #1
Had one of my 996SPS main bearings loose a bit of the outer surface of one of the balls so need to replace it. I've searched long and hard on here and anywhere else I can think of but haven't come up with much about replacing them with hybrid ceramic bearings.

To give you a bit of background info this is a 2000 996SPS, which I only track. I rebuilt this engine a few years ago http://www.ducati.ms/forums/56-superbikes/222737-996-sps-engine-build.html?highlight= but the basics are;
Blueprinted and balanced,
Heads skimmed 0.2mm,
Squish 1.0mm
Valve timing 107/107
Custom map on PC111
STM slipper

The results were fantastic and the bike goes like stink.

After about a year and a half of club racing I discovered some shiny bits in the oil that looked like the outside of a ball bearing so pulled the motor and fitted my spare but now it is time to fix this one. After opening her up we found that it was one of the balls in one of the crank bearings. Out of interest, if anyone read the rebuild story, the bushes were still tight. :)

I've approached Microblue and Woodcraft about their ceramic bearings but they need me to give them the bearing numbers as they aren't an off the shelf item which I'm in the process of doing. I've no idea of the cost yet and they may be way outside my budget but from what I can find on the internet it would seem that hybrid ceramic bearings are about the best one can get.

So does anyone have any info or experience, good or bad, that they can share with me, as to whether this is a good or bad idea?

Thanks

Bront
 

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If you are good with suppliers in the US, youll want to speak with Dave at World Wide Bearing. For the last 20 years, he has been supplying the best bearings in the market- standard, hybrid, and full ceramic.
 

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Back in the 80's as part of the BSY-1 Combat System upgrade for SSN-688 (and BSY-1, Block 1 on the SSN-21 boats) we retrofitted both the Main Sea Water Pumps and TurboGenerators with Active Magnetic Bearings that we designed. The goal, as usual, was noise reduction, as well as accurate shaft position and the elimination of lube oil circulation. Without getting into too many details we designed Thrust, Radial and Angular Contact assemblies for both applications and in each case, backup bearings were an issue (for startup, shutdown and power failure) as we no longer had any lube oil for standard bearing types. The solution came from a company called Cerbex, who made ceramic bearings.

A company rep from Cerbex came to NUWC (Naval Undersea Warfare Center) to demonstrate the bearing strength for us... he was in and out of there in under an hour. When he arrived, he carried an 18" diameter by 2.5" thick plate of 304 1/2 Hard Stainless... in the center of the disc was a blind hole, with a flat bottom, approx 1" in diameter, as well as a plug of slightly smaller diameter, which fit in that hole. He also had with him a 10 Lb Sledgehammer. The bottom of the hole in the plate had numerous semi spherical indentations... similar to the results of a Rockwell Harness Test, only larger. The gentleman from Cerbex dropped a single 10mm ceramic ball into the bottom of the hole, inserted the plug, and then invited all of us to take the sledgehammer and have at it. Needless to say, it stood up to every single impact, seemingly without issue.

The MSW and especially the TG have enormous shafts, that weigh thousands of pounds. Those bearings stood up to everything we threw at them... am pretty sure they can handle the mass and forces generated by a 996 crank.
 

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Have not used ceramic for Ducati application yet but always used ceramic bearings in my Yamaha race motor builds. Always used World Wide Bearing sourced through the good people at Woodcraft.
 

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I am not sure what time frame you need this in but I have access to the oem bearings and buy parts from woodcraft so I could call and talk to them with the numbers in hand ( I am a couple hours drive from them). The bearings may not be available in the type needed but I would not mind finding out, cost is the biggest issue besides availability as oem are a couple hundred dollars (us) a set so I would expect ceramic to be much more.

I am not sure what you mean by hybrid ceramics are you meaning ceramic balls in steel races? If so I am not sure it fixes your problem as I see races flaking chrome more than the balls themselves.
In the states there is a holiday season right now so getting them might be hard for the next week.
 

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Discussion Starter #6
Thanks guys.

Yes Ducvet by hybrid I mean steel races with ceramic balls. I'm not sure that I have a problem really. I suspect that the ball sheading some of it's case hardening is probably a manufacturing fault, as I've never seen or heard of it before and I'm not too concerned that it will ever happen to me again. From what I read it just appears that these bearings would offer significant advantages over normal bearings and if they weren't ridiculously more expensive then a worthwhile upgrade.

I'm not in any rush, as I have another engine that I'm using and my season is finished till next year anyway. I'm in contact with Woodcraft but waiting for my engine guy to give me the bearing numbers but if you have them handy and are interested in finding out, then I would be most grateful.

Does anyone know if preload would be any different?
 

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A previous failure from using aftermarket SKF crank bearings led to a conversation with SKF's technical department who at the time was working with Ducati race department.

The stock Made in England (RHP ?) bearings are a specific "load angle". The mentioned number was 40 degrees & 15 degrees, whichever one was incorrect was the problem for the failure.

It's been a number of years ago so I'd be guessing at which number is the correct load angle. Yet the incorrect angle causes the same flaking of material as you experienced. Perhaps the ceramic ball my be stronger, yet the race may be the weak part if the angle is incorrect.
 

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They are called angular contact bearings and are specific because the cranks are preloaded. Remember the cases grow with heat so if the preload is not right you might not have enough preload when under use. This could allow the crank to move around under use and would lead to damaged bearings the ceramic balls may be up to the task given ProphetPVD's experience but what about the races? In his story the ceramic balls held up but what about the surfaces the balls were against.

I see mostly race failures but have seen the balls fail as yours did as well. From what I can see the greatest cause outside of improper preload is from chemical damage. Years ago I looked into the cause and it led me to believe the common link was most of the bikes effected were bikes were they were stored with contaminated oil. Acids from combustion (blowby) that set in your crankcases for extended periods can soften the metal enough that if you have a bearing that is less than perfect it can start the process of fretting.

I see bikes that are street bikes lose the left side main about 90% of the time with the exception of bikes with center stands. Race bikes are the most common to lose either right or left but I cannot remember if I have ever found a right side bearing failure on a street bike without a center stand. Because of this any bike that has oil blackened by blowby should be changed before storing it for any long term.
 

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Discussion Starter #9
Well it's definitely not from contaminated oil, because I change it often, more than I think necessary to be honest.

But first I need to find out if they are available and what the cost will be and then I'll make a decision if I'll go for it or not.

Thanks for all your thoughts guys.

Bront
 

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Discussion Starter #10
Ok, so I have found two options, both in the USA. The option from one company is for me to source standard bearings and then they will replace the balls with ceramic ones. That costs about $45 per bearing. The other company does the complete bearing for around $225. Left and right bearings are different sizes.

These prices aren't as scary as I thought so I'm quite tempted, however I only need to replace 1 of my bearings so at the moment I'm not sure which way to go.......
 

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Ok, so I have found two options, both in the USA. The option from one company is for me to source standard bearings and then they will replace the balls with ceramic ones. That costs about $45 per bearing. The other company does the complete bearing for around $225. Left and right bearings are different sizes.

These prices aren't as scary as I thought so I'm quite tempted, however I only need to replace 1 of my bearings so at the moment I'm not sure which way to go.......
Not sure why there is really any question, you are in there now, replace both with new ceramic, buy the complete bearing option. Go for it!
 

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+1 on replaceing both, using complete bearings, remanufactured doesn't sound like a good option to me. I'd replace any other bearings i could with glass while i was in there but that's me.

Now that i think about it though, bearing inside the engine i think run with very little drag being in oil. Maybe just replace the bearings in the belt rollers.
 

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Discussion Starter #13
From what I understand they all take a new steel bearing, remove the steel balls and replace them with ceramic balls. Very interesting read from these guys. HOW BEARINGS ARE MADE

The thing with buying the correct standard ones is I would know that I have the correct load angle as mentioned by 916duc.
 
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Before you get really obsessed with your crank bearings, take a long hard look at the areas around your main bearings. They can and often do crack between and through the stiffening ribs if the engine spends a lot of time under high load and revs. I've had really good luck with the OE Ducati bearings in my 900SS and 851/955 race bikes. I have found cracked cases in both bikes after a few seasons without any bearing issues. I did replace the main and rod bearings every season when I freshened things up. I recall the factory had a fairly short cycle out schedule for the cases,cranks etc. on the race engines due to metal fatigue.
 
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