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Marv......rather than lower the mounting hard point for the hyd cyl to
operate the door......how about using the original factory installed
hard point?  This way an original installation can still be used.
This would allow a finished builder to install in a retrofit mode
without changing hydraulic lines as well.  To modify an old
installation or build from scratch just fabricate and install a door
attachment fitting which is a little taller than the one depicted in
the original builder's manual.  The taller fitting will reach the hyd
rod end of the original plan.  Likewise when the door is opened....
the taller fitting is now long enough to reach beyond the inside edge
of the tunnel to allow the hyd rod end to hold the door open.  Like
you say Marv.....the mechanical advantage is still increased because
the new attachment is closer to the center of the door since the new
door is wider and attached about one inch outboard of the tunnel
opening.  I feel the first time installation would be no different
than a retrofit installation because of the geometry involved and
variable placement and length of the door attachment fitting.

Be watchful....an aluminum hinge which is touching the honeycomb skin,
of this skin area, must not be allowed to move (as in vibrate).  The
dirt accumulation along with vibration will wear a line contact along
and parallel to the edge of the nose tunnel.  This wear will
eventually penetrate the skin causing a weak spot along the edge of
the tunnel.  This could violate strength of the tunnel contact with
the bottom skin.  Make sure there is no chance of movement of the
hinge.  I feel a bonded hinge approach is better than rivets.  Screw
holes through honeycomb to reach nut plates is not vibration free,
over time.

Jerry Grimmonpre'  L320   McHenry, IL

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