I am looking for these dimension from the flywheel 13-b RX-7 if someone
have one on hand uninstalled i would really appreciate those
informations
see photo

Jean Prudhomme

 Which dimensions? hole spacing? Diameter? Hole size? How exact do you
 need... I happen to have one off the plane right now :-)
 -- David Leonard
 Dave you are insured. Sky Smith had the info on you. You are famous.
 As far as I can tell you can fly the RV4 anytime.
 Apparently two successful off airports counts for a lot :)
 I need a medical and and bi annual. Both have recently expired. I got
them
 for
 flying in Oz.

 Paul Lamar


 Hi David i will need all holes diameter and holes circle so i can
compare
 with
 the RX_8 flywheelThank's for your assistance


 Jean Prudhomme


 Jean, I received the damper plate today. All is well. Thanks.
 If someone hasn't already given them to you, I picked up my RX-7 flex
 plate from
 the hangar today. I will measure it tomorrow if you still need them.
 C. Smith


 C. Smith Thank's for your response of received the damper plate,yes i
still
 need the holes dimensions on the RX-7 flywheel just to compare if both
are
 interchangeable, but i found an idea to use the RX-8 flywheel and the
 standard Tracy damper but Paul recommend 4130 instead of aluminum plate
but
 it will add a few pounds, you see the rx8 one  is design differently
then
 the rx7 with those big holes away of center holes and closed to the
ring
 gear and by using a bolted plate to the original holes 12mm the Tracy
damper
 plate by attaching the rubber bushing holes and are line up with the
rx8
big
 holes for the bolts head clearance.There is a sketch for this
additional
 plate no welding and no balancing i guess it worth to try.


 Jean Prudhomme

Jean,

The center 6-bolt pattern is the same for the RX-7's and the RX8.  But
that
is not the whole story. There are 2 different fly wheels (use with
manual
transmissions) and 2 different flex plates (used with automatic
transmissions).  Divided thus:

"non-turbo" flywheel - used with all manual n.a. RX-7s  This is smaller
diameter than:
"turbo" flywheel - used with all manual turbo RX-7s and all manual
RX-8's
RX7 flex plate - used with all auto RX7's
RX-8 flex plate - used with all auto RX-8s (and there is a cosmo flex
plate
as well)
 -- the flex plates require the appropriate counter weight and that
supplies the 6-bolt holes
 -- The fly wheels have the counter weight built in.. unless you are
using
an aftermarket flywheel, in which case most will bolt up to the counter
weight.  The aftermarket flywheels come in many different weights and
materials

Tracy used the RX-7 flex plate and his damper plate will not directly
fit
on
the RX8 flex plate or either of the flywheels.  The flywheels put the
ring
gear in different locations from each other, with the n/a RX7 being
smaller
than the Turbo RX7/RX8.

But I have not been able to figure where the RX7 auto flex plate puts
the
ring gear in relation to the flywheels (though it seems to have the same
number of teeth as the turbo RX7/RX8 flywheel)

Tomorrow afternoon I will be able to get to the hangar and let you know
the
size of the -7 flex plate relative turbo flywheel.  Since the flywheels
are
already really beefy, I was hoping there might be an easy adaptation of
one
that would put the ring gear and damper place in the right spot...  but
that
is seeming more and more unlikely.

--
David Leonard

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

This will work Dave. .090" thick ought to work. Jeff can cut it.
Individual spacers for each bolt or a ring spacer will work. Longer
bolts
for the counter weight connection.

Paul Lamar

--


 You might talk me into a ring spacer, Though a flat plate will not be as
 stiff as one that is stamped into a bell shape like the flex plate.  Also,
 don't forget that the ring gear sits basically around the damper plate
 because the flex plate has a recess (see pic -disk on right is flex plate,
 left is turbo flywheel).

 --
 David Leonard

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

 Yes but it is tig welded on so it can be tig welded on a flate plate.
 However Jeff can machine a recess if necessary.

 Stiff is not good. You want a bit of flexibility.

 Perhaps it is time to look at a different damper.
 Here is an off the shelf damper found in off road motor cycles.
 Then the damper will not be fighting the flex plate.

 Paul Lamar

 Hi, the SGF donut coupling is what Porsche used in their aircraft engine.

Murry Rozansky

RotoMax used a Centiflex. The problem is they are rather RPM limited.
175 Newton/Meter is only 200 foot pounds and they are limited to 6000 RPM.
As they go up in torque capacity the max RPM comes down.

Paul Lamar