Dave and All,
Ok Dave the "ACT" "Streetlite" 13.8 lb flywheel was just delivered and I am in process of taking
your measurements to see where we stand................This flywheel is a thing of beauty (to a RotorHead)
and my RD1C drive plate will bolt to it with no problem (through drill and spotface the rear of the flywheel
because it has a slight taper in that area).............I just have to verify just where the RD1C drive splines
will be positioned (fore and aft) on the input shaft compared to the RX7 flexplate.............The clutch plate
friction area is slightly raised (about 0.065) above the clutch mount area and I would probably take it
down tto the clutch level (probably not necessary but would reduce weight slightly.............I have a 93-95
Turbo starter on the way (should take care of starter mesh problem)..............If you are interested I can
guide you to another 93-95 starter (used $49.00 with/shipping) if it is still for sale.............
One other thing at this time..............The lighter 9.8 lb version may be usable but it is listed as 116
ring gear teeth and I have not found out what its diameter is and what starter would be used with it......
I suspect it may be the diameter of the NA 13B flywheels and may use the 86-91 NA manual trans
starter............You need to talk to the manufacturer..........They are in Lancaster, Calif............The 9.8 lb
version is a little more expensive due to more extensive machine work to reduce weight.............See the
link below............The link to THMotorsports has the best price I have found on the 9.8 lb flywheel......The
photo on their page is not the Rotary 9.8 lb version...........
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: Kelly Troyer <keltro@att.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Friday, July 15, 2011 12:34 PM
Subject: [FlyRotary] Re: Ok Here are the important
flywheel measurements
Dave and All,
Sounds encourageing...............Replacing the starter with turbo model would seem to be
least expensive and safer than adding additional ring gear + welding..............I also echo what
Bill and Bobby have said concerning the Al Wick fix and getting Tracy's thoughts about cause
of problem and perhaps need for periodic inspection and/or rubber isolator replacement........
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: David Leonard <wdleonard@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thursday, July 14, 2011 11:41 PM
Subject: [FlyRotary] Ok Here are the
important flywheel measurements
I finally got to the hangar and measured out my S5 turbo flywheel and the remains of my S5
flexplate. The results are very encouraging, even as good as the possibly could be to make the swap, but I only had ten min at the hangar before I had to leave to pick up my daughter from daycare, so they are one try and slightly sloppy... I make no guarantees. The height measurements of the flex plate were particularly suspect because, well, mine is all warped and broken.
Ring Gear Diameter - Perfect fit. As we suspected, same size, same tooth spacing.
Ring Gear Fore-Aft Placement - As measured from the underside of the big nut. (for all further reference, aft means aft in the CAR). The flex plate puts the aft side of the ring gear 1.290 inches from the front of the big nut. The flywheel puts it 0.913. So the flex plate puts the ring gear (
appx)
0.377 in. further aft. This is actually fortuitous because it just so happens that the ring gear thickness is .365 ... So all we have to do to fix the discrepancy is weld and extra ring gears onto to the flywheel ring gear and there will be teeth that the starter can reach:(bottom of the page.. the cost $80)
http://mazdatrix.com/flywheel.htmIt may also be possible to fix the discrepancy by changing the starter... will look into that.
Damper Plate Placement - On the flywheel, the mounting surface is proud (or aft) of the ring gear. On the flex plate, the mounting surface is recessed (or forward) from the ring gear. And it all pretty much works out. That position on the flywheel will vary somewhat depending on which flywheel you have and how much wear you have on the clutch slip surface. But on my (I assume well-worn)
flywheel the placement was 0.965 while the flex plate was 0.950. Pretty damn close and given measurement error it might me meant to be right on. Or, any difference could be made up by trimming down the spline on the damper plate or removing or adding spacers between the two.
So in my mind, a flywheel is the way to go. Stout, easy to get, pick your weight, only mods seem to be drilling the mounting holes and welding on a second gear ring.
--
David Leonard
Turbo Rotary RV-6 N4
VYhttp://N4VY.RotaryRoster.nethttp://RotaryRoster.net