X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 16 Jan 2012 08:18:15 -0500 Message-ID: X-Original-Return-Path: Received: from imr-db03.mx.aol.com ([205.188.91.97] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5351434 for lml@lancaironline.net; Sun, 15 Jan 2012 19:16:23 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.97; envelope-from=vtailjeff@aol.com Received: from mtaomg-db01.r1000.mx.aol.com (mtaomg-db01.r1000.mx.aol.com [172.29.51.199]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id q0G0Fj4O019574 for ; Sun, 15 Jan 2012 19:15:45 -0500 Received: from core-mna002c.r1000.mail.aol.com (core-mna002.r1000.mail.aol.com [172.29.106.5]) by mtaomg-db01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 92C08E000088 for ; Sun, 15 Jan 2012 19:15:44 -0500 (EST) References: X-Original-To: lml@lancaironline.net Subject: Re: [LML] Re: Exhaust system - steam gauges In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: vtailjeff@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CEA1FB1F9BB762_9C8_34C5AD_webmail-m139.sysops.aol.com" X-Mailer: AOL Webmail 35138-STANDARD Received: from 24.107.65.42 by webmail-m139.sysops.aol.com (149.174.9.26) with HTTP (WebMailUI); Sun, 15 Jan 2012 19:15:44 -0500 X-Original-Message-Id: <8CEA1FB1F8D6F1C-9C8-10220C@webmail-m139.sysops.aol.com> X-Originating-IP: [24.107.65.42] X-Original-Date: Sun, 15 Jan 2012 19:15:44 -0500 (EST) x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:443076480:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33c74f136c3020db This is a multi-part message in MIME format. ----------MB_8CEA1FB1F9BB762_9C8_34C5AD_webmail-m139.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Do you intend to fly this in the clouds? I have no steam gage backups. With dual screens, backup batteries and dual= ADHRS I feel that I have enough redundancy. Does anyone have input or com= ment? This plane may be one of the first with no round gauges anywhere. -----Original Message----- From: William A. Hogarty To: lml Sent: Sun, Jan 15, 2012 10:40 am Subject: [LML] Re: Exhaust system - steam gauges Colyn: =20 Well said...... but dont forget the airspeed =20 Bill H. On Fri, Jan 13, 2012 at 12:22 PM, Colyn Case wrot= e: Hi Ed, re: no steam gauges The concern over an all electric system is "common failure mode". In other words, what takes out one system may be the same thing that takes = out the other one. In your installation you have added to that that you have the same brand eq= uipment in primary and backup positions? Also you may or may not have them on fully isolated busses. So here are some of the failure modes you have to worry about: - lightning causes a transient throughout the entire electrical system. T= his one can take out both busses and if you have a portable linked to one o= f your main systems (or not) it can take that out too. - internally caused transient takes out everything on one bus. examples: = alternator over voltage - yes you should have protection for that but it's = not instantaneous. generally that kind of protection is designed to keep = the wiring from melting down. will your equipment survive that? another = example: high current short to ground. this can happen in a faulty motor = (e.g. gear pump) ; chafed wiring etc. same issue with protection: your eq= uipment may be dead by the time the breaker trips. another example: loos= e ground in your charging system causes spikes. I had this happen on my = cessna. It took out 3 different Garmin units before I discovered it. - software issue. some particular sequence of events gets your dynon's con= fused so you have to reboot. ....or some electrical mode turns out not to= be well protected on you dynon's. Since you have the exact same model, t= hey could go out at the same time. Will you still be right side up by the= time they reboot AND the AHRS get re-oriented? - chip and circuit failure. One issue that I think is completely under-app= reciated by the consuming public is that chips fail. They contain tiny tra= ces which are created by a combination of photo-lithography and chemical pr= ocesses. One such trace can be a little thinner in one chip than another c= ausing the chip to fail under certain operating parameters. Not all of the= se are caught in testing. It's a percentage game. The chip vendors try t= o strike a balance between the cost of testing and the cost of replacement.= In the pc world what typically happens is there is a test run of many tho= usands of chips. Some percentage of those will have problems. The problem= s are analyzed and the masks or the process are tweaked. Then the first p= roduction run of millions begins. Some small percentage of those will fail= in the field. Those failures are analyzed and the process is tweaked agai= n. Part number 40 million will have a very small probability of failure, = but it's still non-zero. In combination with the chip failure problem is circuit failure problem. T= he dirty secret of digital electronics is that when they talk to each other= , analog issues become significant. Therefore, digital circuits get tweak= ed by modification of capacitor and resistor values and other tricks to try= to clean up the signals on the board until they are "good enough". =20 If you now consider that the entire production run of all dynon units forev= er is likely less than a test run of pc chips, you can appreciate where you= are in the march to reduced defects with an aircraft product. Last and not least, many people confuse probability and severity. Just be= cause not many units fail doesn't mean that yours won't kill you if it does= fail. Most high school girls don't get pregnant but the ones that do are= not at all comforted by the fact that their chosen method of contraception= "only" had a 1% failure rate. A spinning mass AI is highly recommended. The upside of having one if you= need it so much more outweighs the aesthetic downside of dirtying your pan= el with non-digital stuff. Colyn On Jan 13, 2012, at 6:26 AM, Ed Gray wrote: =20 Here=E2=80=99s a question for Chris, Paul, and others with knowledge of L2 = exhaust. My 360 with Superior IO 360 is ready for engine start up. The ex= haust is a 4 into 1 built by Sonic Headers in Princeton, Mn. It is beautif= ul work and ceramic coated. Sonic provided me with a clamp to fit over the= large pipe (collector exit). This will need to be fastened to the undersi= de of the fuse in some manner, but I question whether it is necessary. The= collector is bolted to two of the headers with stainless dogbones and 3/16= bolts. The headers are of course very solid on the block. The additional= clamp would need to be rubber mounted to allow engine movement. I see no = way the collector or any part of it can ever depart the plane. Is this cla= mp necessary? =20 I just have completed the install of a 2 screen Dynon Skyview system with a= p and Dynon txpd with traffic, Garmin SL30 radio to give ILS presentation o= n the Dynon screen. I have no steam gage backups. With dual screens, back= up batteries and dual ADHRS I feel that I have enough redundancy. Does any= one have input or comment? This plane may be one of the first with no roun= d gauges anywhere. =20 Next issue, my battery is an Odyssy 650 (650 cranking amps) which has been = sitting around for 5 years. It does not turn the crank fast enough for sta= rting. Is 650 amps enuf for a 360 (8.5 compression). I probably need a ne= w battery but don=E2=80=99t want to buy one undersized. =20 I really appreciate this website-very informative! I will post pics when t= he plane is together. Look for N360 ZG at Oshkosh! =20 Ed Gray, Dallas ----------MB_8CEA1FB1F9BB762_9C8_34C5AD_webmail-m139.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8" Do you intend to fly this in the clouds?
I have no steam gage backups.  With dual screens= , backup batteries and dual ADHRS I feel that I have enough redundancy.&nbs= p; Does anyone have input or comment?  This plane may be one of the fi= rst with no round gauges anywhere.
=



= -----Original Message-----
From: William A. Hogarty <billhogarty@gmail.com>
To: lml <lml@lancaironline.net>
Sent: Sun, Jan 15, 2012 10:40 am
Subject: [LML] Re: Exhaust system - steam gauges

Colyn:
 
Well said...... but dont forget the airspeed
 
Bill H.

On Fri, Jan 13, 2012 at 12:22 PM, Colyn Case <colyncase@earthli= nk.net> wrote:
Hi Ed,

re: no steam gauges

The concern over an all electric system is "common failure mode".
In other words, what takes out one system may be the same thing that t= akes out the other one.
In your installation you have added to that that you have the same bra= nd equipment in primary and backup positions?
Also you may or may not have them on fully isolated busses.

So here are some of the failure modes you have to worry about:

- lightning causes a transient throughout the entire electrical system= .   This one can take out both busses and if you have a portable linke= d to one of your main systems (or not) it can take that out too.

- internally caused transient takes out everything on one bus.   = examples: alternator over voltage - yes you should have protection for that= but it's not instantaneous.   generally that kind of protection is de= signed to keep the wiring from melting down.  will your equipment surv= ive that?   another example: high current short to ground.   this= can happen in a faulty motor (e.g. gear pump) ; chafed wiring etc.   = same issue with protection: your equipment may be dead by the time the brea= ker trips.    another example: loose ground in your charging syst= em causes spikes.    I had this happen on my cessna.  It too= k out 3 different Garmin units before I discovered it.

- software issue.  some particular sequence of events gets= your dynon's confused so you have to reboot.   ....or some electrical= mode turns out not to be well protected on you dynon's.   Since you h= ave the exact same model, they could go out at the same time.   Will y= ou still be right side up by the time they reboot AND the AHRS get re-orien= ted?

- chip and circuit failure.  One issue that I think is com= pletely under-appreciated by the consuming public is that chips fail.  = ;They contain tiny traces which are created by a combination of photo-litho= graphy and chemical processes.  One such trace can be a little thinner= in one chip than another causing the chip to fail under certain operating = parameters.  Not all of these are caught in testing.   It's a per= centage game.  The chip vendors try to strike a balance between the co= st of testing and the cost of replacement.  In the pc world what typic= ally happens is there is a test run of many thousands of chips.  Some = percentage of those will have problems.  The problems are analyzed and= the masks or the process are tweaked.   Then the first production run= of millions begins.  Some small percentage of those will fail in the = field.  Those failures are analyzed and the process is tweaked again. =   Part number 40 million will have a very small probability of failure= , but it's still non-zero.

In combination with the chip failure problem is circuit failure proble= m.  The dirty secret of digital electronics is that when they talk to = each other, analog issues become significant.   Therefore, digital cir= cuits get tweaked by modification of capacitor and resistor values and othe= r tricks to try to clean up the signals on the board until they are "good e= nough".  

If you now consider that the entire production run of all dynon units = forever is likely less than a test run of pc chips, you can appreciate wher= e you are in the march to reduced defects with an aircraft product.

Last and not least, many people confuse probability and severity.   Just because not many units fail doesn't mean that yours won't ki= ll you if it does fail.   Most high school girls don't get pregnant bu= t the ones that do are not at all comforted by the fact that their chosen m= ethod of contraception "only" had a 1% failure rate.

A spinning mass AI is highly recommended.   The upside of having = one if you need it so much more outweighs the aesthetic downside of dirtyin= g your panel with non-digital stuff.

Colyn



On Jan 13, 2012, at 6:26 AM, Ed Gray wrote:

<image001.gif>=20
Here=E2=80=99s a questio= n for Chris, Paul, and others with knowledge of L2 exhaust.  My 360 wi= th Superior IO 360 is ready for engine start up.  The exhaust is a 4 i= nto 1 built by Sonic Headers in Princeton, Mn.  It is be= autiful work and ceramic coated.  Sonic provided me with a clamp to fi= t over the large pipe (collector exit).  This will need to be fastened= to the underside of the fuse in some manner, but I question whether it is = necessary.  The collector is bolted to two of the headers with stainle= ss dogbones and 3/16 bolts.  The headers are of course very solid on t= he block.  The additional clamp would need to be rubber mounted to all= ow engine movement.  I see no way the collector or any part of it can = ever depart the plane.  Is this clamp necessary?<= /FONT>
 
I just have completed th= e install of a 2 screen Dynon Skyview system with ap and Dynon txpd with tr= affic, Garmin SL30 radio to give ILS presentation on the Dynon screen. = ; I have no steam gage backups.  With dual screens, backup batteries a= nd dual ADHRS I feel that I have enough redundancy.  Does anyone have = input or comment?  This plane may be one of the first with no round ga= uges anywhere.
 
Next issue, my battery i= s an Odyssy 650 (650 cranking amps) which has been sitting around for 5 yea= rs.  It does not turn the crank fast enough for starting.  Is 650= amps enuf for a 360 (8.5 compression).  I probably need a new battery= but don=E2=80=99t want to buy one undersized.<= /div>
 
I really appreciate this= website-very informative!  I will post pics when the plane is togethe= r.  Look for N360 ZG at Oshkosh!=
 
Ed Gray, Dallas


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