Date: Thu, 12 Dec 1996 17:11:56 -0800 (PST)
From: Mike West <mwest@cdsnet.net>
Subject: Old cases and faying surfaces

  In a way I hate to bring this subject up.

 Everything from flames to total condemnation. 

 Still, bravery is another word for stupid isn't it?

 I'm working on an old case that has one thing going for it.
It's never been bored and doesn't need it now according to my keen 
eye and straight edge.

 All the faying surfaces are totally black tho so I went to work with
some medium emery cloth. By hand, I should add. This is not work for
power tools of any kind.

 I carefully polished every surface and all bearing saddles.

 You know what the black stuff is? Aluminum Oxide. Know what your
sharpening stone is made of? Samo Samo.

 Results: one area adjacent to the oil sump cover was pittedd so bad
from water/acid, I had to get the dremel in and clean it all out and
fill with J.B.W.

 The oil sump cover surface was also so pitted I ground some out and 
and then used the cover plate and coarse grinding compound to grind a 
new flat surface. It might have not leaked with lots of gaskets and 
permatex but it would have been a major pain.

 The mating case-half surfaces had three gouges across the face where some
nice fellow had driven a screw driver or what to get the case apart.
 Filled those and carefully brought them down to the rest of the 
surface.
 Polished the case studs and the o-ring surfaces at the base.

 Polished the o-ring surfaces where the push rod tubes fit. Two of these
were gouged by a screw driver. They were light enough I could 
polish them out. Had they not been, I'd of had a leak there.

 Polished the thrust bearing faying surfaces. I don't know for sure 
but I don't think the al.Oxide would stay there under load or if it 
did it would eat my thrust bearings.

 This Al-oxide is abrasive and brittle as one would expect.
It's my opinion in areas of rotation or flex, it would spall off and 
go into the oil. Good bye bearings and gears.

 I think that doing this polishing in some areas might be unnecessary
if lots of permatex is used but it has hidden primary purpose of giv-
ing an inch by inch inspection of every trouble spot.

 Next are the cam folower holes and the dizzy hole but I need to find
some kind of burnishing tool to get in there. Anyone ever used one
of those many-balls-on-a-stick jobbies?

 The floor is open to debate or suggestion. 

 I'll add a footnote that yes I'm going to have to clean every oil
passage in the thing when I'm done.


  west