Breathing + CO

[QSHIPQ@aol.com]

Phil writes:
>...
>HOWEVER - this is only true for engines that have good cam and crank
>seals, and have been set up as Audi lays down - with all the breathers
>_DISCONNECTED_ and plugged.  Do it this way, then reattach the
>breathers.  If the engine performs differently, you have a leak in the
>engine.  The VAST majority of people who set up an ur-quattro engine
>don't disconnect and plug the breathers - over time, they gradually
>'correct' for the increased air leaks in the engine every time they set
>the CO.  It isn't a true correction, though - it actually moves the
>enrichment curve slightly and leads to a top-end performance fall-off.
>...
>Phil

I haven't found this to be true at all phil.  Setting the CO with or without
breathers hooked seems to make little measureable difference.  Now, since audi
gives a 50 +/- 8 window on the DC, if you set for the low end of the spec
(which gives better WOT DC) with breathers connected, you will find that the
CO reading is fine with them disconnected and plugged (the "proper" way).
BTDT.  Not sure about the leaking seals, but the majority of leakers that I
find are in the cam seal, not anywhere else.  Bad hoses (and they can get
really bad) are number two, the one that feeds into the air boot turns to
mush, so does the one to the block.  The T at the valve cover tends to split
on the bottom next.  Then, I've seen blockage IN the hose (/pipe) that goes
from the valve cover to the block (caused by not changing the oil regularly).
Other seals?  Done them, but only cuz I was there, not AS the cause of any
problem.  Can they go?  Sure, I remember your post.  However, spending a lot
of time on the breather disconnect to properly adjust CO, just doesn't catch
up to the actual numbers measured.  There is enough wet oil in that system on
a point in time disconnect, to throw your numbers just as easily.  

My .02

Scott Justusson