X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 01 Jul 2013 08:01:05 -0400 Message-ID: X-Original-Return-Path: Received: from nm49-vm2.bullet.mail.gq1.yahoo.com ([67.195.87.232] verified) by logan.com (CommuniGate Pro SMTP 6.0.5) with ESMTPS id 6355636 for lml@lancaironline.net; Sun, 30 Jun 2013 13:42:47 -0400 Received-SPF: none receiver=logan.com; client-ip=67.195.87.232; envelope-from=mattreeves@yahoo.com Received: from [98.137.12.174] by nm49.bullet.mail.gq1.yahoo.com with NNFMP; 30 Jun 2013 17:42:11 -0000 Received: from [98.136.164.71] by tm13.bullet.mail.gq1.yahoo.com with NNFMP; 30 Jun 2013 17:42:11 -0000 Received: from [127.0.0.1] by smtp233.mail.gq1.yahoo.com with NNFMP; 30 Jun 2013 17:42:11 -0000 X-Yahoo-Newman-Id: 203489.40169.bm@smtp233.mail.gq1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: MZVybJcVM1npuMiy4oYIjWAZx5TjboBlFloIrImntoCZ5fe H52UvKI9fvIVFo8kedcliOWotsGmgR33gnJvOIPJ0CeuB6FiYilovexUrNa8 Aeboh0tWccYFnYvIcpbeH2CHtSsQ3G5UtCLCzLOG8Fw5kgnXq4.6U1LTGGkU niPW2n1Y_niD09Rrod9xf.lG0jssrKlF0s_rfrb.6y3AuCCOYwMS_So2LXDQ 4.sEqKbmrcxJOE_ewMnqj_D2VfQMA7tix7ADKGF84zhgnnS4kmaPrVd08v2I oj_458LmcyXU3bRvlWYjXWK3Is6i.wE1PVQIS28HerVZXpxvNBTgdPGiHMSI VmvH741JE9ziIV8HONUD2epugYcUNkI8xeX.5dMy1T5iU0N7YQ9lQFZxO7WC Jx5K0mNQeVhAVbWYlXQ7ifBvP.Llb_6v2GDV8pt.yuLhjhw9hyUKnWiTUlxc FFWZiML7UztYrlqB8pB3.D16BQtk7cXxjJik96J0EUsFoXBQu7iEgW7pa7qp rTDlVkYcquJVwGFVZMJJVUJlWpfpWOxXeaVdXu2gPQvtgAaH3SVV_dNtC X-Yahoo-SMTP: N.ZOxbWswBD5ggwr4ThIq1diG15SL24- X-Rocket-Received: from [10.250.252.141] (mattreeves@174.226.67.27 with ) by smtp233.mail.gq1.yahoo.com with SMTP; 30 Jun 2013 17:42:11 +0000 UTC References: In-Reply-To: Mime-Version: 1.0 (1.0) Content-Transfer-Encoding: 7bit Content-Type: multipart/alternative; boundary=Apple-Mail-FA92A148-0895-42A4-B653-C73B345AA63A X-Original-Message-Id: <8694741B-9817-4F3D-A870-305E569094CF@yahoo.com> X-Original-Cc: "lml@lancaironline.net" X-Mailer: iPhone Mail (10B329) From: Matt Reeves Subject: 320 Rudder blueprints ?? X-Original-Date: Sun, 30 Jun 2013 13:42:05 -0400 X-Original-To: Lancair Mailing List --Apple-Mail-FA92A148-0895-42A4-B653-C73B345AA63A Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Does anyone have a set of Rudder blueprints for the ribs, spar?? Building another rudder.=20 Matt Reeves mattreeves@yahoo.com On Jun 30, 2013, at 12:12 PM, Walter Atkinson wro= te: > Colin: >=20 > AT critical altitude the turbine is at max speed with the wastegate closed= . 1649TIT is still OK, but you only have a one degree under the limit. At a= ttitudes UNDER that, the wastegate is not fully closed and the turbine speed= is at something LESS than max RPM. The temp required to cause a problem is= higher than 1650dF, but we don't know exactly what that is, so we still use= 1650dF as the limit=E2=80=A6 but there is some more margin than we think. >=20 > Walter Atkinson >=20 >=20 >=20 >=20 >=20 > On Jun 27, 2013, at 7:19 AM, Colyn Case wrote: >=20 > Walter, >=20 > Can you please elaborate on: > The turbo may be safely operate at 1649 all day long without concern. A s= a matter of fact, that number is conservative unless one is at critical alt= itude. >=20 > I'm specifically wondering what is changing at critical altitude. The wa= stegate is closed, cooling is minimal, but does TIT not correlate in the sam= e way to turbine speed? >=20 > Colyn >=20 > On Jun 27, 2013, at 9:04 AM, Walter Atkinson wrote: >=20 > Bob: >=20 > Based on hard data, there are some significant misstatements in your post.= I will comment in line. >=20 > **To run a TSIO 550 lean of peak, it must be operated below 75% power.** > Many of these engines are operated above 75% power as a matter of routine w= hile controlling CHTs. This usually requires operating it LOP. As Confuciu= s say, "Do not tell man something impossible when he already do it!" >=20 > **but it=E2=80=99s important that you know--and operate the engine at lowe= r power settings--if you want to run LOP. ** > There is absolutely NO reason not to operate the engine LOP at high power s= ettings. Literally, thousands of pilots are doing so quite successfully. >=20 > **When you run rich of peak, some of the fuel is used directly for cooling= and passes through the engine without burning. As a matter of course, it co= ols by evaporation, and leaves nasty lead and other deposits behind=E2=80=A6= on plugs, valves, etc. ** > The heat of vaporization of any extra fuel in a ROP mixture is not even a b= lip on the radar screen in BTUs available for cooling. The reason a richer m= ixture runs cooler than, say 50dF ROP, is that the richer mixture burns slow= er placing the thetaPP further from TDC. This results in lower internal cyl= inder pressures and fewer BTUs transferred across the thermal boundary layer= . Extra fuel does NOT cool a cylinder. A full rich mixture relying on heat= of vaporization for cooling would not be 1 degree cooler! >=20 > **So when you run LOP and eliminate this source of cooling, you must offse= t it by either reducing power (total heat produced) or increasing cooling (b= etter baffling). ** > When LOP, the leaner mixture slows the burn even mores than a richer mixtu= re and cooling is even better. It is possible, therefore, to operate at hig= her power settings LOP with the same CHTs as ROP, or at the same power setti= ng with cooler CHTs. >=20 > **So as you lean the mixture toward max cylinder EGT, you=E2=80=99re reduc= ing the amount of fuel available for cooling and the CHT=E2=80=99s go up.** > No. See above. >=20 > **With most Continental engines, this doesn=E2=80=99t happen at the same f= uel flow for all cylinders, that is, one cylinder reaches peak EGT at a give= n fuel flow (around 16-17 GPH if you=E2=80=99re running about 65% power) as y= ou lean, while the other cylinders are still rich of peak EGT. You need to n= ote the fuel flow when the first cylinder reaches peak EGT. As you continue t= o lean, the EGT (and CHT to a lesser extent) of the first to peak starts goi= ng down, while the remaining cylinder EGTs (and CHTs) continue to go up. Eve= ntually, all cylinders reach peak EGT and start decreasing. Note the fuel fl= ow when the last cylinder reaches peak EGT and just starts to decrease. The d= ifference in fuel flow between first and last cylinder EGT to peak is the =E2= =80=9CGAMI lean test.=E2=80=9D Ideally, the fuel flow between first and last= should be less than 1 GPH; use of GAMIs can tune this to less than half a g= allon per hour, BUT NOTE THAT THIS IS OPTIMIZED FOR ONLY ONE POWER/RPM setti= ng, so you should test/set up the engine at the normally-expected cruise pow= er setting.** > Well, sort of. You have correctly explained the GAMI Lean Test. The spre= ad between the first and last to peak in GPH is called the GAMI Spread. 1gp= h is pretty poor. GAMI shoots for a Spread of 0.3 and most engines will run= "smooth enough" with a Gami Spread of 0.5 or below. While the GAMIjectors w= ere originally "optimized at 2300rpm (not any particular power setting) test= ing has shown them to remain quite well balanced along a wide range of rpms a= nd power settings. The GAMI Spread will change very little UNLESS you have i= nduction leaks. >=20 > **Here=E2=80=99s the rub: You need to be sure all cylinders are at least 3= 0 degrees below their peak EGT when operating the engine in cruise power, an= d this is critically important when LOP. Ideally, all cylinders are all oper= ating at about the same amount below their individual peak EGTs, but the act= ual temperatures are not significant=E2=80=A6it=E2=80=99s the peak value and= delta below--for each cylinder--that=E2=80=99s significant. If the fuel flo= w is not well balanced among the cylinders, the first to peak EGT will get s= o lean by the time that you get the last to 30 degrees below peak EGT that t= he first to peak starts mis-firing. My cylinders start mis-firing at about 1= 20 degrees LOP as a reference point. Mine are well enough balanced (no GAMIs= ) that I can operate the richest cylinder at 60 degrees LOP and the leanest c= ylinder (first to peak when leaning) will remain below 100 degrees LOP. That= equates to about a 0.5 GPH fuel flow difference FOR MY ENGINE=E2=80=A6but t= his varies a lot from engine to engine, and with the power/RPM setting. ** > How far LOP one should set the mixture is dependent upon the power being p= roduced, not some magic number that always works. For example, at 65% power= , 20dF LOP is adequate. I operate routinely at 87% power and set the mixtur= e at 70-80dF LOP. >=20 > **BTW, the TIT=E2=80=99s ARE CRITICAL, and you=E2=80=99ll want to watch th= ese while you=E2=80=99re fiddling with the EGTs. Continental says the max TI= T is 1750 and the max continuous is 1650. I am more conservative, and have a= =E2=80=9Cyellow warning=E2=80=9D set at 1550 and a =E2=80=9Cred alarm=E2=80= =9D set at 1650. As you lean the engine, TIT=E2=80=99s will increase with EG= Ts, and will continue to increase for a short time after the first EGT peaks= are reached, and then start decreasing. I normally see about 1500 on my TIT= s in cruise flight; I lean the mixture more if they go above 1550 in cruise f= light.** > I know of no scientific data to support your recommendations of keeping TI= Ts under 1550. Doing so may keep you 100dF ROP or more, but it is doing not= hing for the life of the turbo. The 1650 TIT limit is for max rotor speed a= t max temperature. The turbo may be safely operate at 1649 all day long wit= hout concern. A s a matter of fact, that number is conservative unless one i= s at critical altitude. >=20 > **Continental says the max CHT is 460 d --Apple-Mail-FA92A148-0895-42A4-B653-C73B345AA63A Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Does anyone have a set of Rudder bluep= rints for the ribs, spar??

Building another rudder.=  

Matt Reeves




On Jun 30, 2013, at 12:12 PM, Walter Atkinson <= walter@advancedpilot.com>= wrote:

= Colin:

AT critical altitude the turbine is at max speed w= ith the wastegate closed.  1649TIT is still OK, but you only have a one= degree under the limit.  At attitudes UNDER that, the wastegate is not= fully closed and the turbine speed is at something LESS than max RPM.  = ;The temp required to cause a problem is higher than 1650dF, but we don't kn= ow exactly what that is, so we still use 1650dF as the limit=E2=80=A6  = but there is some more margin than we think.

Walter Atkinson


<= br class=3D"Apple-interchange-newline">

On Jun 27, 2013, at 7:19 AM, C= olyn Case wrote:

Walter,

Can you please elaborate on:
<= div>
The turbo may be saf= ely operate at 1649 all day long without concern.  A s a matter of fact= , that number is conservative unless one is at critical altitude.

I'm specifically wondering w= hat is changing at critical altitude.   The wastegate is closed, coolin= g is minimal, but does TIT not correlate in the same way to turbine speed?

Colyn

On Jun 27, 2013, at 9:04 AM, Walter Atkinson wrot= e:

= Bob:

Based on hard data, there are some significant misst= atements in your post.  I will comment in line.

**To ru= n a TSIO 550 lean of peak, it must be operated below 75% power.**
Many of these engines are operated above 75% power= as a matter of routine while controlling CHTs.  This usually requires o= perating it LOP.  As Confucius say, "Do not tell man something impossib= le when he already do it!" <g>

**but it=E2=80= =99s important that you know--and operate the engine at lower power settings= --if you want to run LOP.=  **
There is absolutely NO reason n= ot to operate the engine LOP at high power settings.  Literally, thousa= nds of pilots are doing so quite successfully.

**When you run rich of peak, s= ome of the fuel is used directly for cooling and passes through the engine w= ithout burning. As a matter of course, it cools by evaporation, and leaves n= asty lead and other deposits behind=E2=80=A6on plugs, valves, etc. **=
The heat of vaporization of any extra fuel in a= ROP mixture is not even a blip on the radar screen in BTUs available for co= oling.  The reason a richer mixture runs cooler than, say 50dF ROP, is t= hat the richer mixture burns slower placing the thetaPP further from TDC. &n= bsp;This results in lower internal cylinder pressures and fewer BTUs transfe= rred across the thermal boundary layer.  Extra fuel does NOT cool a cyl= inder.  A full rich mixture relying on heat of vaporization for cooling= would not be 1 degree cooler!

**So when you run LOP and eliminate this so= urce of cooling, you must offset it by either reducing power (total heat pro= duced) or increasing cooling (better baffling). **
When LOP, the leaner mixture slows the burn even mores than a ric= her mixture and cooling is even better.  It is possible, therefore, to o= perate at higher power settings LOP with the same CHTs as ROP, or at the sam= e power setting with cooler CHTs.

**So as you lean the mixture toward max c= ylinder EGT, you=E2=80=99re reducing the amount of fuel available for coolin= g and the CHT=E2=80=99s go up.**
No. &nb= sp;See above.
<= br>
**With most= Continental engines, this doesn=E2=80=99t happen at the same fuel flow for a= ll cylinders, that is, one cylinder reaches peak EGT at a given fuel flow (a= round 16-17 GPH if you=E2=80=99re running about 65% power) as you lean, whil= e the other cylinders are still rich of peak EGT. You need to note the fuel f= low when the first cylinder reaches peak EGT. As you continue to lean, the E= GT (and CHT to a lesser extent) of the first to peak starts going down, whil= e the remaining cylinder EGTs (and CHTs) continue to go up. Eventually, all c= ylinders reach peak EGT and start decreasing. Note the fuel flow when the la= st cylinder reaches peak EGT and just starts to decrease. The difference in f= uel flow between first and last cylinder EGT to peak is the =E2=80=9CGAMI le= an test.=E2=80=9D Ideally, the fuel flow between first and last should be le= ss than 1 GPH; use of GAMIs can tune this to less than half a gallon per hou= r, BUT NOTE THAT THIS IS OPTIMIZED FOR ONLY ONE POWER/RPM setting, so you sh= ould test/set up the engine at the normally-expected cruise power setting.**=
Well, sort o= f.  You have correctly explained the GAMI Lean Test.  The spread b= etween the first and last to peak in GPH is called the GAMI Spread.  1g= ph is pretty poor.  GAMI shoots for a Spread of 0.3 and most engines wi= ll run "smooth enough" with a Gami Spread of 0.5 or below.  While the G= AMIjectors were originally "optimized at 2300rpm (not any particular power s= etting) testing has shown them to remain quite well balanced along a wide ra= nge of rpms and power settings.  The GAMI Spread will change very littl= e UNLESS you have induction leaks.

**Here=E2=80=99s the rub: You need to be sure all cylinders are at= least 30 degrees below their peak EGT when operating the engine in cruise p= ower, and this is critically important when LOP. Ideally, all cylinders are a= ll operating at about the same amount below their individual peak EGTs, but t= he actual temperatures are not significant=E2=80=A6it=E2=80=99s the peak val= ue and delta below--for each cylinder--that=E2=80=99s significant. If the fu= el flow is not well balanced among the cylinders, the first to peak EGT will= get so lean by the time that you get the last to 30 degrees below peak EGT t= hat the first to peak starts mis-firing. My cylinders start mis-firing at about 120 degrees LOP as a refer= ence point. Mine are well enough balanced (no GAMIs) that I can operate the r= ichest cylinder at 60 degrees LOP and the leanest cylinder (first to peak wh= en leaning) will remain below 100 degrees LOP. That equates to about a 0.5 G= PH fuel flow difference FOR MY ENGINE=E2=80=A6but this varies a lot from eng= ine to engine, and with the power/RPM setting. **

**BTW, the TIT=E2=80=99s ARE CRITICAL, and you=E2=80=99= ll want to watch these while you=E2=80=99re fiddling with the EGTs. Continen= tal says the max TIT is 1750 and the max continuous is 1650. I am more conse= rvative, and have a =E2=80=9Cyellow warning=E2=80=9D set at 1550 and a =E2=80= =9Cred alarm=E2=80=9D set at 1650. As you lean the engine, TIT=E2=80=99s wil= l increase with EGTs, and will continue to increase for a short time after t= he first EGT peaks are reached, and then start decreasing. I normally see ab= out 1500 on my TITs in cruise flight; I lean the mixture more if they go abo= ve 1550 in cruise flight.**
I know of no scientific data to support your recommendations= of keeping TITs under 1550.  Doing so may keep you 100dF ROP or more, b= ut it is doing nothing for the life of the turbo.  The 1650 TIT limit i= s for max rotor speed at max temperature.  The turbo may be safely oper= ate at 1649 all day long without concern.  A s a matter of fact, that n= umber is conservative unless one is at critical altitude.

**Continental= says the max CHT is 460 d
<= /div>
= --Apple-Mail-FA92A148-0895-42A4-B653-C73B345AA63A--