GMartinez

iTrader: (91)

just for ease of mind bench warm the engine & take a couple of soft laps & you should be good

GMartinez

iTrader: (91)

+1 Roe

DJ_Shakespear

exactly, no engine likes to run crazy while it's cold. Ceramic or not, it has to be ready to go all out otherwise problems will come up either during the race, or just later in it's life faster than it should.

West03

I need further clarification, is it correct that if you use ceramic bearings then you don't have to run oil in the fuel because the bearings does not need lubrication?

rias5037

iTrader: (4)

I have a Max .12 MF with ceramics, we run 16% for clubs and nationals here, the engine has done about 3.5 litres of fuel, never had to change the bearings, just the conrod and the wrist pin, i do however after every meet put about 2-4 drops on after-run oil in the engine and drop in the carb and turn the flywheel by hand a couple of times.

If you dont overheat the engine, all the internals, bearing included will last alot longer, 3.5lts on the same bearing and they are as good as new.

DJ_Shakespear

No, that would be incorrect.
Ceramic bearings do require lubrication to keep things working, but unlike steel bearings they operate under less frictional force and don't generate as much heat as steel bearings. That's why they can run using less lubrication. You still need oil in the fuel to cool the engine (to a point) and so the other parts like the rod and pin areas can still be functional and not fail!
This is what I've read somewhere on the Boca Bearings site I believe, so if they are wrong, then I would be too considering I got this information from them.

So if somebody actually knows and can confirm what they say, just tell me - that's how people learn better. Not by basically screaming at them

Roelof

It is not about needing less lubrication the whole time. At higher RPM's you do come to a limit that lubrication does not work well. We do reach that every time on the straight. Low friction materials like DLC coatings and ceramic may run on low lubrication for a short moment without damaging instantly.

DJ_Shakespear

Correct. But I dont think that lubrication becomes much of a problem once you start reaching the 42,000 RPM mark, hardly any engine no matter what brand doesn't see that much RPM very often. And if it does, that would most likely be it's peak on a track IMO.

In a ceramic Vs steel comparison, under the same RPM and load circumstance, the ceramic bearing does not generate as much heat caused by the load and the friction of the balls and races as it rotates compared to a steel bearing.
Ceramic materials have a much lower coefficient of friction, which means that with the same surface contact area a steel bearing has as well, the amount of friction is a lot less in the Ceramic, so with that you get a more free spinning bearing that essentially runs cooler and can spin faster and easier then the highest quality steel bearing, unless its a poorly made ceramic Vs a Swiss "ABEC 10" steel bearing!! Plus the ceramic material is a lot lighter than steel materials which adds to reduced rotating mass!

fairgo

Something just to think about, the higher the rpm the more fuel you run, which in turn means more oil thru the motor.
Most bearing in motors are not ceramic they are only a hybrid steel case with ceramic balls.
Lubricant oil is also friction (drag on the engine internals)

DJ_Shakespear

True, but if you think about it, the HSN is supposed to keep the flow constant mor-or-less, so you're right in saying more fuel is going through per second, but not per revolution, if you get what I mean.

Roelof

True but the raised heat is affecting the viscosity and working of the oil. More rpm does also mean more strokes so per stroke it does not use more fuel/oil, maybe even less......

JIM1

This is anal.

It is common sense to warm your engine before hard usage whatever bearings you use.

If the bearings are fcuked after a couple of gallons then replace them, ceramic or not. Chances are you would want a new engine by then anyway.

Roelof

The main issue is that the Novarossi bearings aren't that what they supposed to be, a 5 liter of use maximum is becomming quite normal. Drivers are searching for a reason and do look it in their use and fuels while the bearings are just crap.

DJ_Shakespear

Yes, you definitely have to warm up the engine to operating temps no matter how good the engine is. Its just how it all works. Ceramic or not, the engine runs differently when its cold compared to normal temps.

Pattojnr

iTrader: (19)

i didnt mind the blue ceramic balls of novarossi a couple of years ago. since they have gone to the black ones, had nothing but problems.
generally i will run in the motor , use it a couple of round days, then replace to steel bearing. they seem to last longer. and i dont really see a huge performance loss from it