Mailing List flyrotary@lancaironline.net Message #64258
From: Todd Bartrim bartrim@gmail.com <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: tailwheel training; was: Re: Turbo report
Date: Thu, 23 Aug 2018 16:48:32 -0700
To: FlyRotary <flyrotary@lancaironline.net>
Yeah, I can agree with that. I actually had a friend fly up here in his little Thorp S-18 to help me transition and we only intended to do a couple of runs to check the stability then go fly a circuit as we still had MVFR but as we were on our way onto the active runway, conditions dropped below minimum and we were unable to fly. It just got worse so he actually had to leave his own plane here and fly home on a commercial flight. Conditions had improved so he was scheduled to return tomorrow so we could get into the air, but now it's so bad that our country's PM showed up today for a photo op!
I felt I was done taxiing for now anyways as these tires don't wear well on pavement, so I'd like to get going onto grass soon.
This delay is quite disappointing, but not very far away there are families losing their homes to the forest fires, so I really don't have much to complain about.

But I did make use of this delay to make an un-modification to the oil system, but thats a topic for another post...

However my friend is very impressed by the stability of the RV9 with these big tires, but he's very used to the Thorp which apparently is quite snakey. The other thing he is very impressed with is the power and smoothness of the rotary. He's not the same guy who has previously helped me with test flying who has also come to admire the rotary, so another slow convert coming around.....

I had another old timer up at the airport who saw my project many years ago when the rotary was still on a stand as a bare block and he said "you're not going to put that little wankle on this thing are you?"
So last year when I was unable to get parking up there due to last years fires, I ran into him and he said "you put a real engine in there yet?"
This year again, "you got an airplane engine yet?"
So last week as I was doing a little tweaking on the oil system he comes over and takes a look and says "well it looks good, I'll give you that much"
So this week as I was just putting it together he wanders over just as I'm about to fire it up to check for leaks, he wanders over. I give him a heads up and fire it up, run it up to get full oil pressure, then back to an idle and climb out to check for leaks (it's tied down solid), while it's purring softly. I could see it pain him to say it, but he says "that actually sounds pretty good".
So as old timers are prone to do, he starts telling stories. During the next 40 minutes as we're standing beside the airplane it idles smoothly without a single cough, hiccup, or stumble and he repeats about a dozen times a variation of "damn, that sounds good!" and "sure is smooth".
I doubt I made a convert out of him, but I doubt he'll be asking me about real engines anymore.

Todd Bartrim


On Thu, Aug 23, 2018 at 10:34 AM Tracy Crook rwstracy@gmail.com <flyrotary@lancaironline.net> wrote:
What Charlie said.

Tracy Crook

Sent from my iPad

On Aug 23, 2018, at 06:14, Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:

Hi Todd, 

You'll get diametrically opposed opinions on this, but I'm in the 'don't risk your airplane doing fast taxi runs' camp. In my opinion (with around a thousand t/w hours and about 30 nose wheel hours), running a taildragger down a runway at high speed while trying to *prevent* a takeoff is begging for disaster. It really doesn't teach you anything because you never do this in normal operation. And you've added a *lot* of workload, because you must both keep the tail in exactly the right attitude to prevent liftoff without dinging the prop, and play meatpuppet cruise control with the throttle, for the same reasons. All that while performing the normal duty of keeping the plane straight on the runway. I equate it to trying to balance on one foot on a basketball, instead of dribbling it. For you, maybe spinning a hockey puck on one finger while skating & maneuvering another puck with  your stick. Why try? :-)

If the runway's long enough and I felt compelled to practice while tied to the ground, I'd perform a normal takeoff to well above stall speed, then smoothly pull power & perform a normal landing. But if you're completely new to taildraggers, I wouldn't be doing any of that stuff without an instructor in the right seat, until he tells you you're ok to play alone. Why risk your plane?

FWIW,

Charlie

On Thu, Aug 23, 2018 at 1:40 AM, Todd Bartrim bartrim@gmail.com <flyrotary@lancaironline.net> wrote:
Hi Dave;
  How far downstream of the turbo are you measuring your TOT? 
I measure mine about 16" downstream and so far in static ground runs I only see about 550C max. But I also measure both rotor exhaust ports and while I see temps of 950C, only 2" further downstream where the two streams enter the turbo I measure the TIT at usually 50C or more lower. So distance certainly does allow the the flame to cool, but I also assumed that the turbo was converting some of the heat energy to mechanical energy along with the mechanical energy it is already harvesting from the exhaust gas flow.

I hope to get better data soon but smokey skies from nearby forest fires have darkened our skies and kept me on the ground. Been doing some hi-speed runs on the inactive runway between water-bombers coming and going from their base which use that runway as a taxiway, while I'm trying to get a handle on this tailwheel thing. I think it will be much easier when I can just fly it off, instead of just the tail.

Todd Bartrim


On Wed, Aug 22, 2018 at 5:26 PM Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironline.net> wrote:
Dave

That’s great news. TOT is the outlet temperature? If so I would have expected it to be lower. The last coupe of years I have been successful in keeping climb EGT’s under 1600F on most flights. High OAT and quick fuel stops are the exception. But I think the heat soaked engine and super charger is the cause. Performance actually increases after climbing and everything cools off. Typical F/A for initial climb is 11.3 :1 for 1600F EGT’s. I ended up with an O2 bung on each rotor and tuned for a near perfect match between 28-40” MP.  Unfortunately the EGT spread varies a lot in other flight conditions.  I’m slowly working on a turbo FWF to replace the supercharger. I’ve done most of the work on the header with he exception of wastegate, down pipe and bungs. The turbo is located as faraway from the exhaust ports as I could mount it in hopes of dropping EGT’s a little more. 

Link to photos

Bobby


Sent from my iPad

On Aug 22, 2018, at 5:54 PM, David Leonard wdleonard@gmail.com <flyrotary@lancaironline.net> wrote:

Hi Bobby,

Yes, no new torbo failures since I decided to keep TOT (the only place I measure exhaust) less than 890C.  Basically,  I treat it like an aircraft engine.  Rich of peak for climbing and decending (TOT around 810C) then lean at altitude when the MAP is lower  (around 870C).  Peak TOT is around 915C.  

Dave Leonard 

On Wed, Aug 22, 2018, 3:18 PM Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironline.net> wrote:
Dave

How is the turbo holding up?  Is keeping EGT’s under 1600F keeping it alive?

Bobby 
500 hrs

Sent from my iPad

On Aug 22, 2018, at 5:06 PM, David Leonard wdleonard@gmail.com <flyrotary@lancaironline.net> wrote:

Thanks Kelly!
Yes, I am still using the flywheel and strongly suggest not using the flex plate.  Adaption was easy with a trip to a local machine shop.  Details are in the archives. 

On Wed, Aug 22, 2018, 2:41 PM Kelly Troyer keltro@gmail.com <flyrotary@lancaironline.net> wrote:
Dave,

   Not aware of a flexplate/flywheel replacement made specifically for use with 
Tracy's redrive but Dave Leonard (Turbo/13B-RV6) adapted an aluminum racing
manual transmission flywheel to his redrive after his flexplate developed serious
cracks while qualifying to race at the Reno National Air-Races several years ago.

  Perhaps Dave will jump in here with how he did it.......I know there are a series 
of E mails in the archives with photos of how he did it....As far as I know he still
is flying with this flywheel........FWIW

Kelly Troyer

On Wed, Aug 22, 2018 at 4:17 PM, Pam & Dave Williams padajute@idcnet.com <flyrotary@lancaironline.net> wrote:
Hello,

I am looking for a flex plate for hooking up my 13B to Tracy Crooks redrive.
If that is not available, is anybody making a flywheel replacement?

Thanks,
Dave Williams
Whitewater WI

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Friday, June 29, 2018 9:37 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: flyrotary : Re Tension Bolts

I too broke a tension bolt several years ago and was fortunate enough to get
a set of the NEW ones 0.500" from a friend - highly recommended.
Mazda increased the size of those bolts for a reason and my original set
were all spiraled with silicone ... put a little silicone on the 0.50" as
well.
Jeff


Dave,

Run a spiral of RTV around the body of those tension bolts next time you
remove them.  That will pretty much eliminate the vibration breakage.  Don't
put it on the threads.

Bill B

Hello,

I am a newbie on the site. I have a Tailwind with a 13B and Tracy's controls
with his redrive. To this point I have been very pleased with the
combination. Last month I broke a tension bolt and have ordered new and
improved .500" bolts from Mazdatrix. My original .312" bolts broke from
vibration. I have 20 hours on the motor and never had any cooling issues. I
suppose that means I am over cooled, but that is okay with me. I will make
cooling improvements when I am back in the air. My 13B is stock and I run it
at 6,300 RPM.

Thanks,
Dave Williams








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