Bearings or Bushings?

[APersondek]

I just read that the Garrett turbo on the powerstrokes uses bushings instead of bearings on the compressor shaft.



Does anyone know if Holset uses bearings or bushings on the stock compressor shafts on the turbo's that come on our trucks



Lastly, to make sure I am in the correct line of thinking a compressor shaft that is using bearings instead of bushings should be able to spin more freely and at a higher RPM then one that uses bushings?



note that I have the older 04 non-electronically controlled turbo (though it should not matter what type of wastegate the turbo has)

 

[RustyJC]

Technically, a bushing is a type of bearing, as are sleeve bearings, ball bearings, roller bearings, etc. Are you trying to differentiate between an oil film bearing and a rolling element bearing?



Rusty

 

[APersondek]

sorry for not clarifying..... I wanted to know if Cummins, Navistar, or Duramax engines use ball bearings on the compressor shafts of their turbos.



i am not sure what brand turbo the duramax engines use.

 

[nickleinonen]

sorry for not clarifying..... I wanted to know if Cummins, Navistar, or Duramax engines use ball bearings on the compressor shafts of their turbos.



i am not sure what brand turbo the duramax engines use.

stock engines all have bushing type bearings on them [no ball bearings on them]



i am not sure what the older dmax engines had for turbos [i am thinking kkk, but not sure], but the new 360hp version has a garrett vnt charger [similar to the one on the 6. 0psd]

 

[jelag]

You need to look at the speed that the rotor turns... . it takes a very expensive ball or roller bearing to function at 30,000 rpm..... and than it has to stand up to the heat... and the oil that's going to cake onto it when the engine is shut down when the blasted thing is red hot, because you just pulled off the hill into the rest area and for the last 15 miles the pedal was to the metal... . I'm sure those bearing see 600 to 800 degrees on some shut downs after the oil stops flowing to take that heat away...



And the real answer is that a bushing type bearing is much less money to produce and functions almost as well...

 

[Prairie Dog]

A bushing type bearing will (under normal conditions) last the life of the engine, a roller bearing spools up much faster but will not last nearly as long.

 

[jungledave]

The Holsets on our cummins use bushing type bearings. Turbo engineering group up in Golden Colorado told me that the bushing type was superior in his opinion because the bushing rides in the housing on an oil film similar to a rod bearing and the shaft also rides on an oil film in the bushing and the bushing travels at about 1/2 the speed of the shaft. He said it is very difficult to have a ball bearing travel exactly the same speed of the turning shaft since the ball bearing has to actually contact the shaft to spin. The turbo on our trucks turn at 100,000+ RPM Yes you read it right 100,000 + rpm at full boost. He Ballanced the turbo on my Mistu at 119,000 RPM!!! A bushing type turbo will last a very long time as long as you let it cool before shutting it down and use good oil and a good air filter.