At 02:36 PM 10/3/2002, Mark Keller wrote:

>I hadn't considered a broken helical spring, but a weak helical spring, and
>thin oil at high temps and wear could be an issue.

The relief valve really shouldn't be entering into the issue at all with a
hot engine -- certainly not intermittently.  If the spring breaks you'll
have no pressure, if it's weak the peak pressure will be low but below that
shouldn't make a difference.

>However, I believe I read from David Beierl,  that the circuit  is designed
>with slope sensing, i.e. if a drop or increase is of such a velocity that the
>tolerance would be exceeded, then the circuit arms.  So the circuit could
>easily "jump the Gun" if a slow pressure valve or sudden drop in rpm causes a
>quick drop in oil pressure.

Not me, and I don't believe it's so.  The circuit looks only at rpm (from
the tach signal) and the two pressure switches, on NO and the other NC.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"