X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from QMTA06.emeryville.ca.mail.comcast.net ([76.96.30.56] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with ESMTP id 2980423 for flyrotary@lancaironline.net; Mon, 23 Jun 2008 06:46:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.30.56; envelope-from=wschertz@comcast.net Received: from OMTA09.emeryville.ca.mail.comcast.net ([76.96.30.20]) by QMTA06.emeryville.ca.mail.comcast.net with comcast id hNNw1Z0050S2fkCA602o00; Mon, 23 Jun 2008 10:45:29 +0000 Received: from WschertzPC ([71.57.77.95]) by OMTA09.emeryville.ca.mail.comcast.net with comcast id hNlT1Z00623NHuF8VNlUHo; Mon, 23 Jun 2008 10:45:29 +0000 X-Authority-Analysis: v=1.0 c=1 a=56NUJ6-gGGQA:10 a=TzZXOlw_zF8A:10 a=N8B9JuSIAAAA:8 a=arxwEM4EAAAA:8 a=kviXuzpPAAAA:8 a=QdXCYpuVAAAA:8 a=nUuTZ29dAAAA:8 a=reaBEHe6x5x87jJIHNMA:9 a=Jsh_EI2WnIKUkGAzhfQA:7 a=3yy6ac4wJBJxEAtwfZkYs84cRTQA:4 a=EzXvWhQp4_cA:10 a=MSl-tDqOz04A:10 a=oLyKKK6XQo0A:10 a=SSmOFEACAAAA:8 a=Bv7if9hfofWy3fMKkb8A:9 a=-CqugYmSEutggQIp-EwA:7 a=3jdvHga6MHcaESsiSCM2Tc4FUtAA:4 a=WD2S8eiFAUIA:10 a=V9aB5C61OLQA:10 a=pM-imOxlMqoA:10 a=AfD3MYMu9mQA:10 Message-ID: <87B88195585D4BF6BA82C7A7B6402230@WschertzPC> From: "Bill Schertz" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Another Turbo Bites the dust Date: Mon, 23 Jun 2008 05:45:27 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004F_01C8D4F4.56D138C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16545 This is a multi-part message in MIME format. ------=_NextPart_000_004F_01C8D4F4.56D138C0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Actually, if the oil BURNS before the sensor, it would reduce the O2 = level, what probably happened it the oil was not ignited, and the = 'smoke' seen on John's airplane was an oil fog. Bill Schertz KIS Cruiser #4045 N343BS ----- Original Message -----=20 From: Todd Bartrim=20 To: Rotary motors in aircraft=20 Sent: Monday, June 23, 2008 2:41 AM Subject: [FlyRotary] Re: Another Turbo Bites the dust Doh! Sorry, brain fart. Wasn=92t thinking strait, of coarse it = wouldn=92t detect anything as long as the O2 content doesn=92t change. = Too bad as an early warning of oil consumption would be nice. But = there=92s always the stock low oil level indicator in the pan. =20 Todd Bartrim (Drywall dust must be affecting my brain) =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On = Behalf Of David Leonard Sent: Sunday, June 22, 2008 6:37 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Another Turbo Bites the dust =20 Hi Todd, =20 I did look at the mixture display and as far as I can tell it was = unaffected by the smoke, which makes sense. The sensor detects the = presence of O2, and that should not change significantly with the = burning of a little bit of oil. =20 Dave Leonard On Sun, Jun 22, 2008 at 3:50 AM, Todd Bartrim = wrote: Hi Dave; When you had all the smoke, did you happen to notice what = it did to your mixture display from the O2 sensor? Since mine is located = just downstream from the turbo I'm thinking that the oil burning in the = exhaust would make it go full scale rich. This would be an indicator if = one happened to catch it in time. On one of my initial flights, I had an = oil pressure switch blow out oil directly onto the exhaust, downstream = of the O2 sensor. I had no indications of it at all in the cockpit. The = only reason I knew about it was I had another RV flying chase with me. = He said it looked exactly like an air show smoke system. After I was = told about it, I shut down the engine, set up glide back to the runway = and slowed down to stop the prop (so there would still be oil incase I = needed to restart to make the runway). Once I had slowed down, I could = smell the smoke in the cockpit. So an unexplained full rich mixture reading could be = telling us something we need to pay attention too. =20 Todd Bartrim =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On = Behalf Of David Leonard Sent: Saturday, June 21, 2008 6:40 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Another Turbo Bites the dust =20 Good point about the oil feed Ed. In fact, when my first turbo went, = the folks on the ground saw all that smoke and reported that we were on = fire... we were not on fire, but there was plenty of oil both inside the = exhaust on spilling onto the outside of it. =20 So after that I installed an electric switch that I can use to cutoff = oil flow to the turbo from inside the cockpit. Interesting, with this = failure there was no smoke or oil leakage (yet), but I will flip the = switch for the flight home and cut off the oil supply. Thanks for the reminder! --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Sat, Jun 21, 2008 at 4:58 PM, Ed Anderson = wrote: In my opinion, one of the things that we tend to not pay sufficient = attention to is the extent of the demand we are putting on turbos. = Without getting into the specifics of boost ratios vs ambient pressure, = suffice it to say that a turbo compressor has to work considerably = harder at altitude to maintain the same pressure ratio in the manifold. =20 The ambient air pressure is of course less at 8000 MSL therefore = density less as well and the turbo simply has to turn faster to create = the same amount of boost pressure out of the less dense air. The only = way the turbo can do that is to turn faster at altitude. So you have = that hot rotary exhaust pushing those small turbine blades, faster and = faster. =20 As we have discovered, the stock RX-7 turbo succumbs quickly to = those stresses (simply not designed for them). Even with the TO4 = compressor mod, which clearly helps by reducing the turbine rpm needed = to produce X boost, the stock turbine and bearing just do not appear up = to the stress for long duration =96 although 130 hours is better than I = thought the stock bearings would do. =20 =20 A precaution I would take before flying back with the turbo that = condition is to disconnect and plug the oil line to the turbo. Should = the bearing have taken a worst beating 0r continues to deteriorate, you = would not want to be dumping that precious engine oil into the exhaust = =96 although there should be plenty of smoke to tell you when that = condition occurred =96 if there is anybody around in West Texas to let = you know {:>). So I would disconnect and plug the oil line and coolant = line to the turbo =96 just to make certain no leaks occurred. =20 =20 Just my 0.02. Glad, nothing more happened to the engine or you, Dave. = =20 =20 =20 Ed. =20 =20 =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of George Lendich Sent: Saturday, June 21, 2008 6:24 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Another Turbo Bites the dust =20 =20 It's amazing how fast 130 hrs goes when you are having fun.:-) =20 I took off the exhaust today and too a look. One of the blades on the = turbine wheel is gone, but the axle seems otherwise intact, though it = may be off kilter and that is what is causing the resistance when I try = to turn it. So I am to sure if the problem was primarily the bearing, = or overheat, or overspeed. According to my calculations, turbine speed = should have been well within the green area. (way down around 60k RPM - = near the bottom of the chart.) One difference with this fligh... I usually run well lean of peak, = but this particular leg I was running a little late so I decided to push = it up a bit by running a best power setting. I figured I was OK because = I was high enough that I was only showing 21" MAP. But the failure = happened in descent when I kept best power as I came lower and the = engine RPM came up to about 6300 (more exhaust available). Combination of higher than normal EGT's and 'you number is up, = turbo'??? Dave Leonard Dave, I follow your threads carefully as you have put so much into the Turbo = installation, I don't know anyone who has done more but I'm sure there = are, it's just we/I am not aware of them. From what your saying, I think = your right on the money - heat is the killer (in this case). =20 I personally would like you to try something remote as per suggestions = by others. I think Paul's idea is sound, but may be still to close to = the heat for my liking. George (down under) =20 __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3206 (20080621) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com =20 --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net=20 ------=_NextPart_000_004F_01C8D4F4.56D138C0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Actually, if the oil BURNS before the = sensor, it=20 would reduce the O2 level, what probably happened it the oil was not = ignited,=20 and the 'smoke' seen on John's airplane was an oil fog.
Bill Schertz
KIS Cruiser #4045
N343BS
----- Original Message -----
From:=20 Todd = Bartrim=20
Sent: Monday, June 23, 2008 = 2:41 AM
Subject: [FlyRotary] Re: = Another Turbo=20 Bites the dust

Doh!=20 Sorry, brain fart. Wasn=92t thinking strait, of coarse it wouldn=92t = detect=20 anything as long as the O2 content doesn=92t change. Too bad as an = early warning=20 of oil consumption would be nice. But there=92s always the stock low = oil level=20 indicator in the pan.

 

Todd=20 Bartrim    (Drywall=20 dust must be affecting my brain)

<= SPAN=20 class=3DEmailStyle18> 

-----Original=20 Message-----
From: = Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of David = Leonard
Sent: Sunday, June 22, 2008 = 6:37=20 PM
To: Rotary = motors in=20 aircraft
Subject: = [FlyRotary]=20 Re: Another Turbo Bites the dust

 

Hi=20 Todd,

 

I = did look at=20 the mixture display and as far as I can tell it was unaffected by the = smoke,=20 which makes sense.  The sensor detects the presence of O2, and = that=20 should not change significantly with the burning of a little bit of=20 oil.

 

Dave = Leonard

On Sun, Jun 22,=20 2008 at 3:50 AM, Todd Bartrim <bartrim@gmail.com>=20 wrote:

Hi Dave;

           = =20 When you had all the smoke, did you happen to notice what it did to = your=20 mixture display from the O2 sensor? Since mine is located just = downstream from=20 the turbo I'm thinking that the oil burning in the exhaust would make = it go=20 full scale rich. This would be an indicator if one happened to catch = it in=20 time. On one of my initial flights, I had an oil pressure switch blow = out oil=20 directly onto the exhaust, downstream of the O2 sensor. I had no = indications=20 of it at all in the cockpit. The only reason I knew about it was I had = another=20 RV flying chase with me. He said it looked exactly like an air show = smoke=20 system. After I was told about it, I shut down the engine, set up = glide back=20 to the runway and slowed down to stop the prop (so there would still = be oil=20 incase I needed to restart to make the runway). Once I had slowed = down, I=20 could smell the smoke in the cockpit.

           = =20 So an unexplained full rich mixture reading could be telling us = something we=20 need to pay attention too.

 

Todd=20 Bartrim

 

-----Original=20 Message-----
From: = Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of David = Leonard
Sent: Saturday, June 21, 2008 = 6:40=20 PM
To: Rotary = motors in=20 aircraft
Subject: = [FlyRotary]=20 Re: Another Turbo Bites the dust

 

Good point about the oil feed = Ed. In=20 fact, when my first turbo went, the folks on the ground saw all that = smoke and=20 reported that we were on fire... we were not on fire, but there was = plenty of=20 oil both inside the exhaust on spilling onto the outside of it. =20

So after that I installed an electric switch that I can use to = cutoff=20 oil flow to the turbo from inside the cockpit.   = Interesting, with=20 this failure there was no smoke or oil leakage (yet), but I will flip = the=20 switch for the flight home and cut off the oil supply.

Thanks = for the=20 reminder!

--
David Leonard

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

On Sat, Jun 21, 2008 at 4:58 = PM, Ed=20 Anderson <eanderson@carolina.rr.com> = wrote:

In my opinion, one = of the things=20 that we tend to not pay sufficient attention to is the extent of the = demand we=20 are putting on turbos.  Without getting into the specifics of = boost=20 ratios vs ambient pressure, suffice it to say that a turbo compressor = has to=20 work considerably harder at altitude to maintain the same pressure = ratio in=20 the manifold.

 

  The = ambient=20 air pressure is of course less at 8000 MSL therefore density less as = well and=20 the turbo simply has to turn faster to create the same amount of boost = pressure out of the less dense air.  The only way the turbo can = do that=20 is to turn faster at altitude.  So you have that hot rotary = exhaust=20 pushing those small turbine blades, faster and = faster.

 

  As = we have=20 discovered, the stock RX-7 turbo succumbs quickly to those stresses = (simply=20 not designed for them).  Even with the TO4 compressor mod, which = clearly=20 helps by reducing the turbine rpm needed to produce X boost, the stock = turbine=20 and bearing just do not appear up to the stress for long duration =96 = although=20 130 hours is better than I thought the stock bearings would=20 do.

 

 

A = precaution I would=20 take before flying back with the turbo that condition is to disconnect = and=20 plug the oil line to the turbo.  Should the bearing have taken a = worst=20 beating 0r continues to deteriorate, you would not want to be dumping = that=20 precious engine oil into the exhaust =96 although there should be = plenty of=20 smoke to tell you when that condition occurred =96 if there is anybody = around in=20 West Texas to let you know {:>).  So I would disconnect and = plug the=20 oil line and coolant line to the turbo =96 just to make certain no = leaks=20 occurred. 

 

Just my = 0.02. =20 Glad, nothing more happened to the engine or you, Dave. =20

 

 

Ed.

 

 

 

Ed=20 Anderson

Rv-6A=20 N494BW Rotary Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://members.cox.net/rogersda/rotary/configs.htm#N494BW<= /SPAN>

http://www.dmack.net/mazda/index.html

From: Rotary = motors in=20 aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George = Lendich
Sent: Saturday, June 21, 2008 = 6:24=20 PM


To: Rotary motors in=20 aircraft

Subject: = [FlyRotary] Re:=20 Another Turbo Bites the dust

 

 

It's amazing = how fast 130=20 hrs goes when you are having fun.:-) 

I took off the = exhaust=20 today and too a look.  One of the blades on the turbine wheel is = gone,=20 but the axle seems otherwise intact, though it may be off kilter and = that is=20 what is causing the resistance when I try to turn it.  So I am to = sure if=20 the problem was primarily the bearing, or overheat, or = overspeed. =20 According to my calculations, turbine speed should have been well = within the=20 green area. (way down around 60k RPM - near the bottom of the=20 chart.)

One difference with this fligh...  I usually run = well lean=20 of peak, but this particular leg I was running a little late so I = decided to=20 push it up a bit by running a best power setting.  I figured I = was OK=20 because I was high enough that I was only showing 21" MAP.  But = the=20 failure happened in descent when I kept best power as I came lower and = the=20 engine RPM came up to about 6300 (more exhaust = available).

Combination=20 of higher than normal EGT's and 'you number is up, = turbo'???

Dave=20 Leonard

Dave,

I follow = your=20 threads carefully as you have put so much into the Turbo installation, = I don't=20 know anyone who has done more but I'm sure there are, it's just we/I = am not=20 aware of them. From what your saying, I think your right on the = money -=20 heat is the killer (in this case).

 

I = personally would=20 like you to try something remote as per suggestions by others. I think = Paul's=20 idea is sound, but may be still to close to the heat for my=20 liking.

George (down=20 under)

 



__________=20 Information from ESET NOD32 Antivirus, version of virus signature = database=20 3206 (20080621) __________

The message was checked by ESET = NOD32=20 Antivirus.

http://www.eset.com

 



--
David Leonard

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

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