Date:         Tue, 25 Apr 1995 09:16:02 -0400
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         pwilliam@emr1.emr.ca (Peter Williams)
Subject:      Re: Remember those chips of metal....

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