FULL CERAMIC BEARINGS

[Albert Araujo]

Ok David and Mark,

My objective is to increase performance if at all possible and most of all to not worry any more about my bearings going bad due to residual moisture or nitro.

I decided to start this new thread because the full comp thread did not address my issue clearly. I recently purchased full ceramic bearings for all my engines. I had a choice of either the ABEC 3 or 5. I went with the 5 because I knew it was a better tolerance and higher quality bearing. After reading the recent post on the full comp bearings I want your guys input as to which way to go with the full ceramics.

Back in the days when I was designing and manufacturing the RC turbines, We ran the full comp hybrids at over 160,000 RPM. In the event of a FOD failure the balls would destroy the races but nothing would happen to the balls. I figured this being the case a set of bearings with both the balls and races in Si3N4 would work great under the high nitro and water environment.

In summary, give me your input and forget the money argument. I want to know if they work as well as I expect and what specks to have them built to. What are the correct tolerances for our use and is their a specification that fits these tolerances so I can order them without having to mess with them.

Either of you can call me at 786-280-1246

Thanks,

Albert

 

[Terry Keeley]

I recently tried some re-balled ceramics from Greg Settle, seems to have helped to cure overheating I was having with my 67 saw boat. IIRC Greg re-fits them to C4 clnc which seems real loose when you feel them. Any idea what the hybrid turbine bearings had for internal clnc?

 

[dwilfong]

Yes Greg's bearing do feel lose. that is because thy are.

Albert talk with Greg Settle he is on IW.

He will give you all the info you will need.

When you talk about the fit c3 c4 c5 there are tolerances built in to each fit. Thy will over lap also depending on what point in the production thy are made.

How true the races are is the main thing to look at. Not all races come off the line perfect. there is a tolerance. also all balls are not the same.

If you want the best balls call Greg.

.

 

[dwilfong]

The only reason I did not go with full ceramic is that priced thing you don't want to talk about.

 

[dwilfong]

I pulled out some bearing and checked the notes on them.

The radial play on the ones I am running in my 1.01 are .0011 for the rear bearing and .0008 for the front bearing.

The top range for a industry standard C5 bearing is .0008

Just to give you a Idea of how lose thy are.

 

[ALLAN YUEN]

Very good but depend on what kind of nitro with oil. I had seen in happen with cermic ball beaing . you use better synthetic 100% so can stand long life than castor (short life) because can break splite half ball then go through piston and liner seized so if you can afford all whole replace parts engine???

 

[dwilfong]

It's not the oil it is the clearance is not right.

I run Klotz Super Tecnoplate with Castor in my eng with no problems.

 

[Albert Araujo]

Greg,

It was great speaking with you. I am back in town and was looking for the quote on the bearings we spoke about. Please send it to [email protected]. I need to re build and test before the winter nationals so time is running out. Call me if you get a chance.

Thanks,

Albert

 

[Albert Araujo]

The only reason I did not go with full ceramic is that priced thing you don't want to talk about.

David,

Greg told me he tried the full ceramics a while back and the outer race came apart due to the bore in the case putting stress on the ceramic race. "NOT GOOD"

 

[Lennard Cuenco]

used to race with a mopar mechanic, he had me re-assemble each bearing alternating bearing sizes abec 3's and 5's....worked super good, insane rpms (german wib's i recall), the crank didn't even score the housing or anything...lol

was a blast trying to keep track of 3's vs 5's when we reassembled them...i remember it as an opportunity to practice our cursing

 

[Jerry De Young]

The C rating is the spherical accuracy of the ball. The idea is that on a nitro engine the tolerance will need to be looser as the RPMS are high and the load is high. Also another thing to keep in mind is not just the oil quality but the quantity. If you use to much you will get what is called skidding. The balls will slide around the race and not roll. This is when you start to have failures. Also in the enviroment you are not to expect real long life. A ceramic bearing with debris in the way of the race will basically chew up the debris by crushing it between the inner and outer races. This causes the raceways to become pitted and then they become useless. That was the purpose of hybrids at the time. They had steel which would "Should have" cleaned the raceway and the ceramic would be fine. The steel flexes so to speak as the motor runs it can distort to a small degree without problems. Ceramic does not do this. Hence why you use a looser fitting ball or mixing of the sizes and grades.

 

[Lennard Cuenco]

The C rating is the spherical accuracy of the ball. The idea is that on a nitro engine the tolerance will need to be looser as the RPMS are high and the load is high. Also another thing to keep in mind is not just the oil quality but the quantity. If you use to much you will get what is called skidding. The balls will slide around the race and not roll. This is when you start to have failures. Also in the enviroment you are not to expect real long life. A ceramic bearing with debris in the way of the race will basically chew up the debris by crushing it between the inner and outer races. This causes the raceways to become pitted and then they become useless. That was the purpose of hybrids at the time. They had steel which would "Should have" cleaned the raceway and the ceramic would be fine. The steel flexes so to speak as the motor runs it can distort to a small degree without problems. Ceramic does not do this. Hence why you use a looser fitting ball or mixing of the sizes and grades.

ok..i see...its about precision rather than size...makes sense to me