Dave,
I was under the impression that the steel inserts in the rubber/silicone damper are locked
between the front washer and rear washer (flywheel) and provided the space for relative
movement between the flex-plate (flywheel) and damper plate..............Sounds like you were
getting an extreme amount of bolt (twisting) movement between the flex plate and damper plate
(a lot of hp at high boost) which may have accelerated the flex-plate failure.........I would guess
that the flywheel will eliminate any tendency for the bolts to twist under high boost now............
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: Tuesday, August 16, 2011 12:00 AM
Subject: [FlyRotary] Re: First flight with new Flywheel
Bolt-on would be a stretch, but not too much work either. Measurements were putting the distance between the damper spline and adapter plate at about zero (after the clutch wear surface was taken down). So just to be on the safe side I had the shop take a small bit off the spline while it was in the machine shop. Now there is a small gap. I think I only took off 0.01 or so... Less that half of the end flange (which I wanted to keep mostly intact to resist radial expansion of the spline.
I did not use the washers between the damper plate and flywheel. Currently, they won't fit as they are thicker than the gap between the spline and adapter plate. I could have easily taken a little more off the flywheel and/or spline and they would fit. But I don't really see their purpose anymore. The flywheel makes a nice surface for the dampers to lie against. I see little or no overhang past the flywheel mounting surface. Removing them also reduced the twisting moment on the bolts. Lastly, those washers were really wearing into the damper plate right at the rivets holding the damper support blocks.
The scars on the damper plate from the washers show that I was getting a good 3-4 mm of relative movement between the damper plate and the washers/flex plate. I think that much was not necessary. My silicone dampers are stiffer and there is now direct contact between the flywheel and damper plate so it is possible that I am not getting enough dampening and risk damaging the gears. Opinions?
On Mon, Aug 15, 2011 at 10:11 AM, Kelly Troyer
<keltro@att.net> wrote:
Dave,
Also were you able to use the large washers between the damper/drive plate
and flywheel (as the silicone dampers overhang the outer edge of the flywheel
mounting area slightly) without triming the nose of the damper spline ??............
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: Tracy <rwstracy@gmail.com>
Sent: Monday, August 15, 2011 9:38 AM
Subject: [FlyRotary] Re: First flight with new Flywheel
David,
Was it a bolt on change or was it necessary to shorten the nose of the damper spline to use this flywheel?
Still looking at options.
Tracy
Sent from my iPad
I finally took the new flywheel and silicone dampers out for a flight today. I was hoping for a slight improvement in idle and/or smoothness with the little bit of extra weight in the flywheel, but I guess 4 lbs is just not enough to make much of a difference. I flew around for about an hour and got the RPM up to 7000 and MAP up to 40 in., and loading the plane to 4G (thinking about gyroscopic forces) without any noticeable change in the way the engine sounded or ran. Everything look ship-shape on a post-flight examination.
This is the ACT flywheel that Kelly found for us. Looks bulletproof compared to a flex plate.
Next project, finish installing the ADI system.