Jim (Bus Boys) says:
Bosch Oil Filters bad?  I always get mine from the dealer (It says Audi on
the box)- like the full flow feature when you blow thru them- some have
backflow valves which can impede flow, but since it's at the lowest point
in system, (my 78 engine) the backflow valve is not necessary?  My only
booboo in past was using a filter that has no ridges on it for a wrench-
straps don't fit in there- the secret is to get a board like a 2x4 and
drill two holes in it o one near end, other about 3" away to just fit 12
penny nails- pound them into the filter, turn it off!!

   BTW, this leads to STORY about my 71 bus- I added an oil cooler and
filter by braising on two elbows and copper pipes to the sumplate, and
running the pipes forward to cooler and filter bolted between body rails
and protected by steel mesh plate.  This allowed the oil to be SUCKED up th
e sump pipe as before, but first flows from engine bottom thru cooler and
filter.  Using gauges, it did not lower oil pressure (raised it because coo
ler), and ran fine (from my 110k rebuild to 220 retirement).  Took longer
to pump up when oil changed (due to air in system?) To change oil, pulled
off a clamped hose.   The sumplate still could be pulled to check for
sludge, metal wear.....  MB in NJ