When I rebuilt my 1700 some of the cam bearings (one half only) were worn through the top silvery layer to a coppery layer underneath. I imagine at this point things start to wear pretty quickly. I was suprised as well that only one of the bearing halves had a thrust face (shoulder), but that's the way it was on the replacement bearings also. For $10 or whatever, I don't imagine we're getting the most hi-tech bearings Peter California or Bussed > I _finally_ got around to finishing my engine teardown <'74 1800cc type IV> > and I've found the source of those pesky metal chips. It is the camshaft > bearings <!>. I find this very puzzling - I've had a lot of sh*tty old cars > over the years and this is the very first time I've seen camshaft bearings > give any grief at all. BTW, the rod and main bearings look just fine. The > cam itself shows wear, perhaps not unexpected in an engine with 108 kmiles > on it. > > The bearing material appears to be seperating from the shell backing, coming > off in chunks. The only one that isn't breaking up is the insert with the > flanges on it for thrust. That's another question I have: There are five > bearing inserts with out faces and only one with - is that normal? Intuitivly, > I would expect a pair with thrust faces. The engine is a rebuilt from VWOA, > done in early '80s. > > One hypothesis I have for this failure is that the case is distorted and > has caused the cam bearings to overheat. Another hypothesis is that they > are lousy cam bearings and have slowly been falling apart for years. I'd > appreciate hearing anyone else's thoughts on this. Has anyone on the list > experienced a similar problem? > > Thanks, > > Dave
|
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.