Mailing List flyrotary@lancaironline.net Message #44934
From: David Leonard <wdleonard@gmail.com>
Subject: Re: [FlyRotary] Frying pan... it gets fun!!!
Date: Mon, 26 Jan 2009 05:46:25 -0800
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
HI Chris,
 
Really sorry to hear about the impending rebuild - I know exactly how that feels and it is very dissapointing.
 
IMHO, 225 deg even for a momment could very well be the culprit.  When I melted my o-rings (before first flight because of rust in the housings) - my coolant temps were in that range.  Additionally, regularly getting into the 210-220 range is too hot as well.  I used to use 200 as my redline where I would back off the power (but I would often see 210).  I am now convinced that high temps were the root cause of my stuck and broke side seals and other various engine ailments. 
 
Since I bit the bullet and put in an oversized radiator and rebuilt the cowl to match my coolant temp only gets up to 180 in the very worst conditions (turbo boosted steep climb from a heat soaked engine on a 100 deg day).  Oil is the same, and I have not had a single engine issue in 200 hrs of high power - keep up with my formation buddies mostly flying 200 hp. lycs with c/s props. (turbo failure aside).
 
Follow Al's lead and get a fan on that radiator (if you don't already have one).  Even before my improved cooling system I could taxi around all day and keep it under 200. If you don't have a system that can do that, you will be sorry.  There are frequently delays on the ground in hot weather and the last thing you want is to be the guy shut down in the run-up area blocking everyone because you are waiting for the engine to cool.  Besides, in a tractor configuration, temps will only get hotter in flight.  You backward airplanes may see some improvement in flight but not enough to compensate for an inadequate system.   Do what you need to do to get those temps down.  Its no big mystery...  radiator volume + cooling air = cooler temps. 
 
Anyway, it does get fun.  I regularly take up my friends and family for sightseeing and aerobatic flights.  I am flying to the mountains today to go skiing, last week I landed on a neat little 1000' dirt strip in the desert and impressed the mechanics who worked there with the simplisity, cost effectiveness, and reliability of my engine.  In the mountains when it is 10 deg and everyone else is waiting for their turn to use use the only pre-warmer, I just fire it right up.  On the hot days and all of my formation buddies with fuel injection are worried about not starting - I just fire it right up.  When I hear about an incident involving vapor lock or carb ice, I just smile because those problems cant affect me.  When everyone else is bitching about the price of avgas, I remember that I run mogas that has been saving me consistently $1/gal.
 
Nowadays it is simply about the flying and not all about the engine anymore (it definately used to be all about the engine).  I've been where you are.  You'll get to be just about flying as well.  Keep at it.
 
--
David Leonard

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

On Sun, Jan 25, 2009 at 10:40 PM, Christopher Barber <CBarber@texasattorney.net> wrote:
Perhaps one day I will post with good news.  However, today is not the day. I have really been having some fun as I move my project from "proof of concept mode" to "flight prep mode".  The engine and wires have been my focus since I had to rebuild the strakes in my Velocity following my Jeffco failure.  (BTW, I may have discovered the reason for my Jeffco failure...more on that later).
 
Since I have seemingly gotten most my electrical gremlins tamed as in the engine running, the alternators charging and lights working properly, I was gonna start to actually hook up my Dynon D-100, radios, GPS's and audio panel today.  I was also gonna take out my EC2 and EM2 to send to Tracy to check out one last time (my EM2 backlight stopped working so I figured I would send it all in now while I tied up loose ends). 
 
Since I was about to send my computers in and would not be able to run the engine for a while I couldn't resist pushing the plane out of the hangar and crank her up.  She started up as expected.  I taxied around a bit making my "airplane" into a loud and expensive "go-kart".  I shut down after a few minutes as the temps started to rise.
 
I let the bird sit for a bit and wanted to restart it.  Hmmm, not starting.  Hmmmm.  Let is sit a bit more.  Try again. Still no joy.  I sat there for a minute and remembered it was a bit difficult to start a second time the last couple of times I ran the engine.  UHOH!  When I had to build this engine it was premised by the old engine not wanting to start after an initial run. The first engine got too hot and was leaking coolant into the rotor housings. 
 
I took a big breath and went back to the exhaust.....there was a bit of dirty liquid at the exhaust tip.  Damn.  Ok, take a deeper breath and be a man (no offense Chrissi...I am a man<g>) and go remove a sparkplug and take a look.  Sure enough I removed the leading plug of rotor two and it had a bit of liquid.  I hand turned the prop and steamy liquid blew out the hole. Damn-it, damn-it damn-it!  Coolant in the housing.  Checked the front rotor and same thing, but less liquid. Damn.
 
Ok, when this happened to my rebuilt first engine I blamed myself as I was in a serious learning curve.  I ran it hot without a prop, too hot with a prop and without proper sensors.  I really should have been surprised if I didn't fry it.  So, when it failed it gave me an excuse to buy new housings, end and center plates etc and build what was/is essentially a new engine.  I TOOK EXTREME care as to not to ever let it get too hot.  I would shut it down if it got between 210 and 220.  ONE TIME it got to about 225 degrees before I shut it down and that was only for a matter of couple of seconds.  None the less something has happened to cause coolant to enter the rotor housings again.  I used what were advertised as "beefed up" O rings purchased from Pineapple racing (kinda as a thanks to their rotaryengine illustrated website).  It is my understanding if that if the engine gets too hot these "O" rings fail and let coolant seep through.  Oh, I sooooooo hope it is just the "O" rings and the hardware was spared.  All the hardware is new and professionally ported by Mazdatrix to a medium street port...I really was developing some power.....
 
I spoke with my engineer friend, Blaine, who owns a couple of aviation business with R&D as a major factor as well as building a Soob/Eggenfielder RV-7 and he and I are gonna look into what I missed.  Verify that my sensors are working properly, check the cooling system for proper flow again among other things.  Very frustrating though.  I am, however, getting very good at removing my engine from the plane.  I had it off and sitting on the work table in only about an hour.  I am not gonna crack the engine open yet until I can get Blaine over for some joint brain duty.  On a positive note, there are a number of things at the "firewall aft" that I need to address, this is giving me the perfect opportunity to do so.  They will be much easier to improve with the engine off.
 
Now to resign myself to yet another engine build as we determine the why.
 
And, as to another "why".  I may have determined why my Jeffco failed in my fuel strakes.  As loyal fans may remember I had to remove all the old epoxy/Jeffco from my strakes and redo them completely a couple of months ago due to the Jeffco peeling away.  Well, as I was poking around the hangar looking for something I had placed as to be able to find it easy later......yeah, right, I came across my old Jeffco bottles.  Hmmmm, the Hardener is labeled 3191 and the Resin is labeled 9700.  Now, I remember that when I ordered it a few years ago it was 9700.  I remember specifically as when I first ordered from AS&S they sent the wrong stuff and I returned it for the 9700.  THIS time I ordered new Jeffco, but choose not to use it and just use straight EZpoxy for my strakes, however, in the new order  BOTH the Hardener AND the Resin were labeled 9700.  My current thought is that I used the Hardener that AS&S supplied with the kit assuming (yeah, bad Chris for assuming) that it was the correct one to use with the 9700 Resin....which is what I knew to be the proper number.  It was not until the new order arrived a few months ago and I saw both the hardener and resin are both 9700 and finding the original bottles from a few years ago that I would have ever discovered a problem. 
 
I intend to send a email to the company that bought Jeffco and see if they can verify this conclusion.
 
As always y'all's insight, commentary, Wild ass guesses and demeaning remarks are anticipated and relished.  Please though, no gee Chris, you sure seem to be having a lot of problems.  Yes and No...I just like to share more <g>.  In the tradition of John Slade, share it all, it can only help. Heck, this is the time to break things.  Much easier to deal with now in my own hangar and not on some deserted strip or worse yet, in the air....even if my wallet is screaming.
 
So, the fun starts when???????? :-)
 
All the best,
 
Chris Barber
Houston



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