Well, now...

Recently, I've been stating my worries about my oil temp being too high;
well now I'm worried about the opposite extreme!

Here's some background:
My '71 Westy has only around 4000mi on the rebuilt 1600dp.  I have a
counterbalanced crank, a higher volume oil pump, and an external spin-on
type oil filter.  I've been using 10W-40 oil since the ambient air
temperature is in the 20f to 45f range every day.  I just changed the
oil and filter (a Mann filter) <500mi ago.  I also tuned it up at this
this time, and engine performance seems fine.

And here's the problem:
When first started, the engine builds oil pressure rapidly to 60-70psi, but
it makes a god-awfull rattle/banging sound that, to my untrained ear,
sounds like the dreaded 'rod knock'.  So I let it warm for at least 5 min,
at low rpm (it gets worse at higher rpm), and eventually the noise goes
away (when oil temp is >180f).  Last night on the way home, though, the
noise remained for the whole trip (~50mi).  The oil temp never got much
above 180f, and the pressure never got below about 40-50psi.  As soon
as I got home, I drained out the oil, and it looked awfull!  Not sludgy
looking, but almost like it was diluted with something!  It also had
a silvery sheen to it as it sat in the drain pan (I thought it might
be metal shavings, but I couldn't see any when I took a sample between
my thumb and forefinger).

Here's my theory:
Is it possible that there's too much oil restriction?  Tonight I'm going
to bypass the oil filter and see what happens.  I don't think I've 
damaged anything, or at least (besides the noise) I don't see any
evidence of damage.

Am I overly worried about this?  That noise can't be good, or is it
normal for relatively cool engine?

Dave
'71 Westfalia & SB