[Vwdiesel] Re: running away? WHY?

[Mark Shepherd]

>Why does the blocked screen cause runaway?  Does it
pressureize the block and >blow oil past rings, and past
valve stem seals?

Volumes too small past stem seals to do more than smoke a
little IMO

It causes a problem not because it is a total blockage but
more because it is a partial blockage and as it approaches
'total' the velocities of oil drenched vapour increase and
are no longer filtered by the hidden gauze. Couple this to a
partial vacuum created by the air filter resistance to
piston suction (N/A) or Turbo scavenging  and 'Bob's Yer
Uncle'.

All this is hidden from view on a diesel; but a carburetted
gasser can display it quite dramatically as the oil drips
down the outside of the carb. Happened to me and I convinced
myself that rings had gone and that what was in reality a
modest blowby felt like a gale when that's what I had told
myself. Just happened across an ex VW mechanic (in a wood
store!) who corrected me before I ripped the engine
out }8^D)
Miser