Paul,

  All the X & Y dimensions are from the flat firewall.
  Note there are five mounting points. Designer call for up
 to
  180hp with the four point, with up to 260hp with five
  points.

  I'm trying to get an idea of the room using either a 13B
 or
  20B. Only one Bearhawk is flying (Elden Yates). Little
  details, but Elden ended up putting his battery next to
 the
  PSRU to get some weight out on the nose!

  Plan is to use Tracy Cooks PSRU.  With 180hp,
 Bearhawk
  cruise is 140mph, with 260hp it is at 160 mph (75% on
 both
  numbers).

  --Tom

  There are five mounting points on the Bearhawk Firewall.
  Firewall is
  approximately 2" larger at all mounting points.

  In Inches:                 X        Y
  Lower Left        3.500    0.000    reference    Lower Right        31.188    0.000           Upper Left        0.000    20.188           Upper Right        34.688    20.188           Upper Middle        17.344    24.844                           THRUST LINE        17.344    15.844    Firewall
  set back at 6 degrees (top towards tail).
                         Prop Flange (front edge) to
 VERTICAL MOUNT -
  40.625"        Note, from firewall (6
 degree lean back - top towards tail)
  is sin 6 *
  (Thrust Y position) or an additional
  1.656"             -- end of email ---


  Does this look right?

  Now you want me to lay it back 6 degrees?

  Paul Lamar


       Paul,

 The bottom measurement should be changed from 27.500 to
 27.688"

 Upper middle is 24.844" from the lowest two holes.

 Correct, rotate the firewall back 6 degrees. Point of
 rotation is from
 the lowest two points on the firewall.

 Thank You,

 Tom

 OK Tom Here it is.

 Paul Lamar


      Looks good.

Bob Barrows, the designer, doesn't have an email account! No computer,
either! I suspect that is why he gets so much done.

Thanks,

Tom

I'll see Bob at OSH and show him some of this stuff.

Here are some preliminary 3Ds. Ask questions if you see something
that looks strange. Upper motor mount is not in yet but we
will use a rubber ball jointed strut mount to above the water pump.
Are you using and RX8 engine? That area differs from the 13B.

Paul Lamar