<VV> Droopy turbo?

[jvhroberts at aol.com]

 Sounds like it ran without an oil change, and possibly moments without any oil at all! Turbos tolerate lack of oil pressure far less well than the engine does. That might explain why the bearing was so bad. When this happens, the bearings get chewed up, they don't seize like an engine would. Frozen turbos are almost invariably due to deposits or rust in the turbine housing wedging the wheel, rarely are they frozen in the bearing housing. 

 

John Roberts
 

 

-----Original Message-----
From: Grant Young <gyoungwolf at earthlink.net>
To: virtualvairs at corvair.org <virtualvairs at corvair.org>
Sent: Sun, Nov 8, 2009 7:58 pm
Subject: <VV> Droopy turbo?










I received a turbo for rebuild this week, but have not seen one this bad, so I 
thought I would float the information to see if I can give the owner some ideas 
to make his replacement last longer. This was a 1963/4 model ('63 carb side, 64 
exhaust side). I had to press the (ruined) bearing out and there was evidence 
(gritty gray oily residue on the shaft) that some metal had stared to go 
(probably from a groove in the cartridge as there was a wear ridge on the 
turbine side of it). The most unusual thing was that the blades on the turbine 
appear to have "drooped" to where they were almost touching each other. There 
was a good 1/8" clearance between them (the small inner blades) and the turbine 
housing as a result. Can these things get that hot? There is no sign of contact 
between the blades and housing on either side (although the tip of one impeller 
blade was missing). I was initally thinking a lack of lubrication was the 
problem, but the rotating parts were free (although the
  longitudinal movement was excessive). It was not "coked" but there was 
excessive loose carbon on the outside of the heat shield. The carbon seal was 
not worn excessively, frozen, or cracked, and the internal sealing O-ring was 
still pliable. Any ideas on what killed it? Thanks,
Grant
 _______________________________________________
This message was sent by the VirtualVairs mailing list, all copyrights are the 
property
of the writer, please attribute properly. For help, mailto:vv-help at corvair.org
This list sponsored by the Corvair Society of America, http://www.corvair.org/
Post messages to: VirtualVairs at corvair.org
Change your options: http://www.vv.corvair.org/mailman/options/virtualvairs 
 _______________________________________________