good point. also what about durability? seems to me the journal bearings would run cooler due to the constant oil flow? but then I guess the ball bearings would also need constant oil flow. So that brings up another question wouldn't the ball bearings run a lot slower when immersed in oil depending of course on viscosity ? Maybe we are both saying this "test" means little. I have a lot to learn
@@davidsmith5982 most turbos are cooled by coolant, not oil. Ball bearings also needs an oil restrictor so there's not as much pressure in the bearing as a journal one.
That was literally the first thing that came to my mind. Also I make my Turbo glow for a half hour to 45 minutes at a time during open track events. How well does the ball bearing deal with Extreme engine temperatures? My holset hx35 has been rocking for..... I don't know 16 years. I swear one time I got it glowing so good after a Highway pull it looked like the turbo was transparent.
Well OFC the journal bearing needs oil pressure to work ball bearings (rollerpins) are used in two stroke engines for connecting rods and crankshafts also but not so in hardly any 4 stroke engines because journal bearings carry way more load on them and last forever as long as the oil film is maintained the only time any wear occurs is during the start up and shutdown when oil pressure is not there. Ball bearings create a point load on the race they are running on which can lead to brinnelling but the advantage to a rolling bearing is that they don't require a pressurized oil supply this is why your cars wheels run on tapered roller bearings instead of journal bearings.
I'm sure the ball bearing turbo spools faster but 'd like to see the "flick test" done on the journal bearing turbo with oil pressure applied to it.
good point. also what about durability? seems to me the journal bearings would run cooler due to the constant oil flow? but then I guess the ball bearings would also need constant oil flow. So that brings up another question wouldn't the ball bearings run a lot slower when immersed in oil depending of course on viscosity ? Maybe we are both saying this "test" means little. I have a lot to learn
@@davidsmith5982 most turbos are cooled by coolant, not oil. Ball bearings also needs an oil restrictor so there's not as much pressure in the bearing as a journal one.
That was literally the first thing that came to my mind. Also I make my Turbo glow for a half hour to 45 minutes at a time during open track events. How well does the ball bearing deal with Extreme engine temperatures? My holset hx35 has been rocking for..... I don't know 16 years. I swear one time I got it glowing so good after a Highway pull it looked like the turbo was transparent.
Thank you!
Well OFC the journal bearing needs oil pressure to work ball bearings (rollerpins) are used in two stroke engines for connecting rods and crankshafts also but not so in hardly any 4 stroke engines because journal bearings carry way more load on them and last forever as long as the oil film is maintained the only time any wear occurs is during the start up and shutdown when oil pressure is not there. Ball bearings create a point load on the race they are running on which can lead to brinnelling but the advantage to a rolling bearing is that they don't require a pressurized oil supply this is why your cars wheels run on tapered roller bearings instead of journal bearings.
Mostly agree with you, but you can't compare ball bearing with journal bearing without oil feed !! Doesn't make sens at all
Now let's compare a pneumatic car tire without air to a wagon wheel. As we can see, wagon wheels are superior. lol