This reduces the number of parts.

 The flex plate can be .090" thick 4130 or anything up to 1/4 inch.

 The damper plate has been reduced to one ring part instead of
 a large thick Al plate four Al blocks and 16 rivets.

 A large ring with twelve 1.375 inch holes easily
 drilled on an NC machine. Only four of which are
 used fro the rubber bushings. The rest are there to save
 weight.

 The Ford auto TX part is turned around 180 degrees
 to nest inside the flex plate. Only 10 steel
 10-32 screws are used to bolt it to the damper ring
 instead of 20 rivets.

 The rubber bushings and washers are the same.

 No need to move the starter or change the damper
 design as I suspect would be required with the RX8 flex plate.

 What do you think Dave?

 Paul Lamar


 Looks elegant to me.  Does the "Ford auto TX part" seat into the guide
 bearing in the E shaft?


 Mark LaPierre


 The input shaft with the sun gear does that.
 The Ford part has an internal spline that runs on the input shaft.

 The Ford part is the same as Tracy uses now and it can be salvaged and re
 used by drilling out the rivets.


 Paul Lamar


 If you decide to make a run of these, count me in for one. Or whatever
 solution is decided to be best.
 C. Smith

 This is going to hinge on what Dave says as he is our
 chief part Zerstörer right at the moment.  Mark Steitel is
 second in command with a p-port 3 rotor now flying.
 I'll take over when I get a P-port in the RV4.

 Paul Lamar


 LOL, Thanks Paul.  Nice work.  I really like the idea of a more purpose
 built and dampened connection.  In your design, I don't understand where
the
 dampening is coming from.  If it is all the big holes in the damper plate,
 at first that seems like a good idea then I think than maybe it will make
it
 too firm of a connection unless the the rubber is really soft.

 BTW, I measured Tracy's rubber dampers today:  1/2 inch.

 So I had previously narrowed it down to 2 options, now we add your design
as
 a third:

 1) Paul's design.  Nice, elegant, probably first choice if we spent some
 time hashing out the details.  The cost and work will invariably be higher
 than the off-the-shelf solutions. Cost ??,  Work??

 2)  RX8 Flex plate.  Very easy solution.  Requires an intermediate plate
for
 adaption then it is good to go.  I went to an online machine shop and we
 could get the plate for about $50 (I have it all designed and ready to
ship,
 thanks to Jeans measurements).  The only other work would include welding
if
 you wanted but 4 bolts alone would work fine, and an hour's work with a die
 grinder to bevel the other side of the gear ring.  Cost - $160 for the flex
 plate and $50 for the intermediate adapter.  If welded, this would be
 exceedingly stiff and light weight. (5 lbs for the flex plate, 1.4 lbs for
 the intermediate plate, and 0.8 lbs for bolts if you didn't want to weld.)
 So this is the lightest weight, lowest cost, and least work solution!  But
 it only makes moderate improvements in durability over Tracy's current
 design - which has done very well and moderate improvements should be all
we
 need.

 3)  Off the shelf flywheel.  Requires drilling some holes in the flywheel,
 and possibly machining it to accept the bolts on the back (because of
 non-flat surface) and possibly reduce the height of the clutch surface.
 Also requires wielding on a ring gear to fit the current starter, or (only
 if we are lucky) switching to a different starter.  Durability seems to be
 the toughest of the lot, but with aftermarket stuff you never really know.

 So, I am just a little push from diving into option #2. with option 3 as
the
 favorite if the turbo starter happens to fit...  Kelly has one on the way
to
 test.

 --
 David Leonard

 Turbo Rotary RV-6 N4VY
 http://N4VY.RotaryRoster.net <http://n4vy.rotaryroster.net/
 http://RotaryRoster.net <http://rotaryroster.net/

 The damping is EXACTLY the same as the damping in Tracy's
 design. At this point in time we are only using four holes.
 I don't believe in fixing something that is not broken.
 We do have softer rubber bushings available. Down to 40
 durometer if you want to try them but I don't recommend
 it at this time. The ones we are building now are
 about 70 durometer. If durability of the silicone is
 a problem we can go to more holes.

 Is the RX8 ring gear the same diameter as the 13B?

 I did not think it was. It just looks larger.
 If it is you will need to relocate the starter.

 No holes down near the clamp and the thicker (.090")
 material is a big plus.

 Paul Lamar



I am watching this thread with great interest as I will be using a P
Port configuration with Tracy's RD1C.  Is there any merit in cleaning
the existing flexplate and laying up a several layers of carbon fiber
inthe deficient areas?  The fit would be exact and you could use
faseners if the bond is not adequate.  Carbon fiber needs to isolated
from aluminum do to electrolysis effects and is typiclly isolated by
an outer layer of glass.  In this scenario it would be steel so I am
not sure if the same logic applys.  Any thoughts?

Joe Berki

Not a bad idea. Carbon does not add that much to the centrifugal
mass of the 13B plate. First thing is I would weld sheet metal plugs in the
unnecessary holes near the center. Then apply the carbon.
Actually a pretty good idea. Sand blast the plate so the
epoxy sticks. Use small SS spacer around the mounting holes on
the inside to distribute the stress into the carbon fiber. Do the inside
only as the carbon would be crushed between plate and counter
weight.

Paul Lamar

Paul,

It would be possible to place carbon on both sides around the holes
lapping over the perimeter of the holes trapping the plate between the
carbon and filling the holes.

Joe Berki

Yes but you don't want it between plate and counter weight.
The position of the ring gear relative to the face of
the counter weight is critical.

In my book your idea is best so far Joe.

Paul Lamar