Date:         Mon, 12 Feb 2001 09:43:23 EST
Reply-To:     Wolfvan88@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Robert Lilley <Wolfvan88@AOL.COM>
Subject:      Re: 2.1L Oil pressure problem: Rods: SYMPTOM NOT CAUSE:UNBALANCED
              crank the ....
Comments: To: NotaJeep@aol.com
Content-Type: multipart/alternative;

If you cannot understand the washing machine illustration:

Ice skaters have thin blade that exerts a lot of pressure on the ice to melt
the ice create a grove and then move on that groove.  If the blades were
wide, then there would not be enough pressure to melt the ice and they would
not have any control on the ice.


Think about that in the bearing in the rod edge wear.  IF the rod is not
absolutely, perfectly 90 degrees to the crank journal, as the crank flexes
then the edge that makes contact during the power stroke has increased
pressure and then as the rod wants to equalize the pressure across the face
of the bearing causes the rod to be slammed sideways (depending on rod
location) in the journal.  The constant hitting with one edge first is what
wears the bearing.  The rod wear is dependent of the center bearing wear, as
it wears the angle to the rod increases.  The side also are worn as it twists
in the journal.  This side ways twisting is what causes the big end
elongation.  If the rod bolts or nuts stretched ANY AT ALL, the nut would
back off quickly.  I could see that IF the flex was great enough and the
angle acute enough, that the rod cap could be twisted off.

As the rod bearing wears there is increased room for more oil and the
pressure drops because a predetermined amount now has to do more work.  As
the wear increases, the pressure drops and the journal gets hotter because
there is no longer enough oil to carry the heat away.

The crank is harder than the bearing and the bearing is designed to wear as
the crank makes contact.



[text/html]