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Ball Bearing, Roller Bearing, Jounal Bearing?

chrissso

By chrissso,
in Engines & Forced Induction

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chrissso Proficient

chrissso

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Hey skypeople,

I'm interested to know peoples opinions about the different styles and types of turbos out there and what their pros and cons are.

I think that skylines, from r 32 to 34 and some 31's use ceramic roller bearing tyoe...

Please note that this is only what I've heard and feel free to set me straight if I'm wrong.

This is my knowledge so far - Please confirm.

Journal bearing - uses oil as its bearing against a plate.

pros - quick to spool

cons - needs more time to warm up to a safe operating temp so that the oil lubricates propely, prone to early failure.

Ballbearing - uses ball bearings to hold shaft in place

pros - robust and long lasting, very efficent as in spins freely without much friction, does not have a long warmup time. Very fast.

Cons: slower to spool

Roller bearing - no idea, apart from sound like it would be the same as a ball baering type.

Ceramic - ceramic turbine wheel

pros - lightweight ceramic turbine has low inertia and allows for a quick spool up time - Low rotating mass.

Cons - fails at high boost due to turbine not being as strong as metal turbine.

Does this sound correct?

Thanks

SleepingTalon Contributor

SleepingTalon

Posted
Posted (edited)

Actually, the ball bearing will offer faster spool than the journal bearing based on its design. Ball-bearings use less oil and handle pressure more efficiently and effectively than journal bearings. Journal bearings run on a film of oil and the shaft relies on a constant supply of fresh, clean oil over a very wide contact area. The frictional value is very high on a journal bearing design. The 2 big options offered to most of us is the 270 and 360 degree bearing on the journal bearing turbos. The difference between the 2 is the the 360 has a full circle of lubrication, six orifices on the washer instead of three for the 270. The ball bearing design, althought it's still fed a small amount of oil, doesnt rely on that thin film of oil to support the shaft. This is what allows for the faster spool. Hope this helped some...

Edited by SleepingTalon
chrissso Proficient

chrissso

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The difference between the 2 is the the 360 has a full circle of lubrication, six orifices on the washer instead of three for the 270.  The ball bearing design, althought it's still fed a small amount of oil, doesnt rely on that thin film of oil to support the shaft.  This is what allows for the faster spool.  Hope this helped some...

Thanks for that..

Thats why I asked the question. I couldn't see why journals were faster spool than BB. I guess I got the wrong impression.

Skylines have roller bearing turbos, with ceramic turbine.

So what's the pros and cons between a BB and roller bearing turbo? Is it just that the bearings are cylindrical instead of balls? I think that rollers canhandle more weight, like in a road wheel stiuation. The bearing has to carry the weight of the car...

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