X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 15 Jan 2012 10:39:02 -0500 Message-ID: X-Original-Return-Path: Received: from mail-lpp01m010-f52.google.com ([209.85.215.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTPS id 5349717 for lml@lancaironline.net; Fri, 13 Jan 2012 21:39:10 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.52; envelope-from=billhogarty@gmail.com Received: by lahg1 with SMTP id g1so552212lah.25 for ; Fri, 13 Jan 2012 18:38:33 -0800 (PST) MIME-Version: 1.0 Received: by 10.152.104.131 with SMTP id ge3mr1662534lab.10.1326508713800; Fri, 13 Jan 2012 18:38:33 -0800 (PST) Received: by 10.152.29.70 with HTTP; Fri, 13 Jan 2012 18:38:33 -0800 (PST) In-Reply-To: References: X-Original-Date: Fri, 13 Jan 2012 18:38:33 -0800 X-Original-Message-ID: Subject: Re: [LML] Re: Exhaust system - steam gauges From: "William A. Hogarty" X-Original-To: Lancair Mailing List Content-Type: multipart/alternative; boundary=f46d0408da2dad753204b673e0be --f46d0408da2dad753204b673e0be Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Colyn: Well said...... but dont forget the airspeed Bill H. On Fri, Jan 13, 2012 at 12:22 PM, Colyn Case 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 take= s > out the other one. > In your installation you have added to that that you have the same brand > 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 linked to on= e > 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 designed to kee= p > the wiring from melting down. will your equipment survive that? anothe= r > example: high current short to ground. this can happen in a faulty moto= r > (e.g. gear pump) ; chafed wiring etc. same issue with protection: your > equipment may be dead by the time the breaker trips. another example: > loose 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 > confused so you have to reboot. ....or some electrical mode turns out n= ot > to be well protected on you dynon's. Since you have the exact same mode= l, > they 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-appreciated by the consuming public is that chips fail. They conta= in > tiny traces which are created by a combination of photo-lithography 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 percentage game. The > chip vendors try to 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 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 ve= ry > small probability of failure, but it's still non-zero. > > In combination with the chip failure problem is circuit failure problem. > The dirty secret of digital electronics is that when they talk to each > other, analog issues become significant. Therefore, digital circuits ge= t > tweaked 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". > > 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 > where 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 kill you i= f > it does fail. Most high school girls don't get pregnant but the ones th= at > 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 you= r > panel with non-digital stuff. > > Colyn > > > > On Jan 13, 2012, at 6:26 AM, Ed Gray wrote: > > ** ** > > > Here=92s 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 > exhaust is a 4 into 1 built by Sonic Headers in **Princeton**, Mn. It is > beautiful 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 t= he > underside 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 clamp necessary?**** > > ** ** > > I just have completed the install of a 2 screen Dynon Skyview system with > ap and Dynon txpd with traffic, Garmin SL30 radio to give ILS presentatio= n > on the Dynon screen. I have no steam gage backups. With dual screens, > backup batteries and dual ADHRS I feel that I have enough redundancy. Do= es > anyone have input or comment? This plane may be one of the first with no > round gauges anywhere.**** > > ** ** > > Next issue, my battery is an Odyssy 650 (650 cranking amps) which has bee= n > sitting around for 5 years. 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=92t want to buy one undersized.**** > > ** ** > > I really appreciate this website-very informative! I will post pics when > the plane is together. Look for N360 ZG at ****Oshkosh****!**** > > ** ** > > Ed Gray, Dallas**** > **** > > --f46d0408da2dad753204b673e0be Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Colyn:
=A0
Well said...... but dont forget the air= speed
=A0
Bill H.

On Fri, Jan 13, 2012 at 12:22 PM, Colyn Case <colyncase@earthlink.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 takes 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 a= re some of the failure modes you have to worry about:

- lightning causes a transient throughout the entire el= ectrical system. =A0 This one can take out both busses and if you have a po= rtable linked to one of your main systems (or not) it can take that out too= .

- internally caused transient takes out everything on o= ne bus. =A0 examples: alternator over voltage - yes you should have protect= ion for that but it's not instantaneous. =A0 generally that kind of pro= tection is designed to keep the wiring from melting down. =A0will your equi= pment survive that? =A0 another example: high current short to ground. =A0 = this can happen in a faulty motor (e.g. gear pump) ; chafed wiring etc. =A0= same issue with protection: your equipment may be dead by the time the bre= aker trips. =A0 =A0another example: loose ground in your charging system ca= uses spikes. =A0 =A0I had this happen on my cessna. =A0It took out 3 differ= ent Garmin units before I discovered it.

- software issue. =A0some particular sequence of= events gets your dynon's confused so you have to reboot. =A0 ....or so= me electrical mode turns out not to be well protected on you dynon's. = =A0 Since you have the exact same model, they could go out at the same time= . =A0 Will you still be right side up by the time they reboot AND the AHRS = get re-oriented?

- chip and circuit failure. =A0One issue that I = think is completely under-appreciated by the consuming public is that chips= fail. =A0They contain tiny traces which are created by a combination of ph= oto-lithography and chemical processes. =A0One such trace can be a little t= hinner in one chip than another causing the chip to fail under certain oper= ating parameters. =A0Not all of these are caught in testing. =A0 It's a= percentage game. =A0The chip vendors try to strike a balance between the c= ost of testing and the cost of replacement. =A0In the pc world what typical= ly happens is there is a test run of many thousands of chips. =A0Some perce= ntage of those will have problems. =A0The problems are analyzed and the mas= ks or the process are tweaked. =A0 Then the first production run of million= s begins. =A0Some small percentage of those will fail in the field. =A0Thos= e failures are analyzed and the process is tweaked again. =A0 Part number 4= 0 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. =A0The dirty secret of digital electronics is that when t= hey talk to each other, analog issues become significant. =A0 Therefore, di= gital circuits get tweaked by modification of capacitor and resistor values= and other tricks to try to clean up the signals on the board until they ar= e "good enough". =A0

If you now consider that the entire production run of a= ll dynon units forever 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 p= roduct.

Last and not least, many people confuse probability = and severity. =A0 Just because not many units fail doesn't mean tha= t yours won't kill you if it does fail. =A0 Most high school girls don&= #39;t get pregnant but the ones that do are not at all comforted by the fac= t that their chosen method of contraception "only" had a 1% failu= re rate.

A spinning mass AI is highly recommended. =A0 The upsid= e of having one if you need it so much more outweighs the aesthetic downsid= e of dirtying your panel with non-digital stuff.

Colyn



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

<image001.gif>

Here=92s a question for Chris, Paul, and others with knowledge of L2 exhaust.=A0 My 360 with Superior IO 360 is ready for engine start up.=A0 The exhaust is a = 4 into 1 built by Sonic Headers in Princeton, Mn.=A0 It is beautiful work and ceramic coated.=A0 Sonic provided me with a clamp to fit over the large pipe (collector exit).=A0 This will need to b= e fastened to the underside of the fuse in some manner, but I question whethe= r it is necessary.=A0 The collector is bolted to two of the headers with stainless dogbones and 3/16 bolts.=A0 The headers are of course very solid on the block.=A0 The additional clamp would need to be rubber mounted to allow engine movement.=A0 I see no way the collector or any part of it can ever depart the plane.=A0 Is this clamp necessary?

=A0

I just have completed the install of a 2 screen Dynon Skyview system with ap and D= ynon txpd with traffic, Garmin SL30 radio to give ILS presentation on the Dynon screen.=A0 I have no steam gage backups.=A0 With dual screens, backup batteries and dual ADHRS I feel that I have enough redundancy.=A0 Does anyone have input or comment?=A0 This plane may be one of the first with no round gauges anywhere.

=A0

Next issue, my battery is an Odyssy 650 (650 cranking amps) which has been sitti= ng around for 5 years.=A0 It does not turn the crank fast enough for starting.=A0 Is 650 amps enuf for a 360 (8.5 compression).=A0 I probably need a new battery but don=92t want to buy one undersized.

=A0

I really appreciate this website-very informative!=A0 I will post pics when the plane is together.=A0 Look for N360 ZG at Oshkosh<= u>!

=A0

Ed Gray, Dallas



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