<VV> Tear-down III (was Rebuild II)

[tonyu at roanokeinternet.com]

>
>This is not an automatic transmission nor a formula one
>race motor --  those should be clean inside to start -- but
>an engine can and will be  'dirty' and still work just
>fine!  

Agreed.  You need to have some seriously grubby oil to ruin
an engine in short order, along with a plugged filter which
forces open the bypass valve.   

Then again, if there's a bunch of grit standing in the oil
galleries, all bets are off.   Most standard clean out
techniques already discussed will/should flush the
galleries.     

>One of the reasons for a full flow  oil filter, and
>soft-faced babbit bearings. Those fancy ultra-sonic 
>cleanings of old used oil coolers, when installed on new
>engines  however, *is* money well spent, even if it seems a
>tad spendy, as the  cooler is after the filter (as I
>recall). Tiny fine powder like pieces  and flakes are to be
>expected though -- large pieces of grit and filings  are
>probably questionable.  You need to get some perspective --
>change  the oil in your buddy's or wife's perfectly good
>running car and check  that with your magnet ... 

Lots of fine ferrous particulates end up in the pan of most
engines.   And, most engines don't digest their bearings in
a few miles.   

I think something else is afoot here that we've not seen
yet.   


>What did you do? Forget to use the duct tape to seal off
>the top of the  head while you drilled?  and then used a
>blow gun to clean the hole? If  so, maybe you need to tear
>it down ...  

I'm not sure that aluminum flash or drill debris would
actually hurt a Vair engine if it got dumped into the pan. 
Even if it got past the filter, it would just embed itself
into the bearings and "polish out".   I've pulled engines
down with "salted" bearings filled with little shiny
polished bits of aluminum, and they were still charging
along before the overhaul.   They had not failed because of
the debris.    


Now, if the bits are ferrous, that's another matter.  
However, I'd still not expect catastrophic failures because
of iron grit in the bottom of the pan.   If that had been
the case (ferrous grit ion the oil galleries) it would have
caused other damage on the crank journals, cam, lifter bores
etc.   It wouldn't, for example, have singled out one or two
bearings etc.   Even if a big chunk *had* found its way onto
the crank journal, the chunk would embed into a bearing and
just wear a groove in the crank and not necessarily ruin the
engine.   

Engines that had been "gone through" with hidden dirt left
in them will still usually just soldier on, dirt and all,
without flying apart or spinning bearings...  not for a long
while anyway, depending on how bad they were to begin with. 
 

   
There has to be something else going on here for such short
term failures.    


Gremlins...?  


tony..