RE: NEED OIL COOLED TURBO! (actually, I just learned that it's air cooled)

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

> > I'm still looking for a turbo for my 82 5kt.  I have one that's cooked,
> so I
> > don't need anything that needs a rebuild.  If you have one that's in
> good
> > shape and you'd like to get rid of it quick, please respond ASAP.
> >
> 
> Oil cooled? You mean air cooled as opposed to water? The oil is just for
> lubrication...
> 
... the oil does perform a cooling function as well ... if it did not there
would be no need to let the turbo cool down with the engine running after
hard use, nor would coking of the bearings be a problem ...

The reason the newer turbos use an auxiliary water cooling system to cool
the turbo bearings after the engine is shut down is likely to be that it is
much easier to plumb an auxiliary electrical water pump into the cooling
system than an auxiliary oil pump ... especially given the fact that the
water cooling ports on the turbo are added from the basic turbo ... which
makes me wonder how much water is flowing through the turbo bearing jacket
while the engine is running?  It could actually only be "used" when the
engine is shut off ... I don't know about this one way or the other as it
just came to mind ... I guess I'll have to look at the plumbing to see ...

Steve Buchholz
San Jose, CA (USA)