X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from m12.lax.untd.com ([64.136.30.75] verified) by logan.com (CommuniGate Pro SMTP 5.0.6) with SMTP id 932191 for flyrotary@lancaironline.net; Wed, 18 Jan 2006 20:11:23 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com Received: from m12.lax.untd.com (localhost [127.0.0.1]) by m12.lax.untd.com with SMTP id AABB673Y5AVE3V4A for (sender ); Wed, 18 Jan 2006 17:09:47 -0800 (PST) Received: (from alwick@juno.com) by m12.lax.untd.com (jqueuemail) id LE2SDKJG; Wed, 18 Jan 2006 17:09:02 PST To: flyrotary@lancaironline.net Date: Wed, 18 Jan 2006 16:04:18 -0800 Subject: Re: [FlyRotary] Re: Coil & Alt cooling, Buly's input shaft Message-ID: <20060118.170713.1452.8.alwick@juno.com> X-Mailer: Juno 5.0.33 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=--__JNP_000_3eff.330d.448f X-Juno-Line-Breaks: 8-6,17-27,35-36,48-49,52-58,63-73,76-77,86-87,93-96,107-123,124-32767 From: al p Wick X-ContentStamp: 5:2:266000734 X-MAIL-INFO:4f858504112571797414b904d9b98075454130b940a4351d11403041408140151929c4898521045d047d113980e101397925f529ed6d34bdd53da55075d43dcd84b1f5cd957034390d8191f0e910e538e04959f0ed208df1 X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkC0tXthhavHdFK66hReUbaHVgoIaYYmK7Q== X-UNTD-Peer-Info: 127.0.0.1|localhost|m12.lax.untd.com|alwick@juno.com This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ----__JNP_000_3eff.330d.448f Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Your explanations sound pretty reasonable. I see these situations as great opportunity. Nothing better than when you have fairly consistent fail rate. If bench testing, this would be great time to run 1/2 from different supplier. Place insulation around 1/2 of them to induce failure. Operate at high rpm loads beyond what they can ever see. Goal is to make them all fail. Taguchi DOE approach(L4 design). Sounds weird at first, but breakthroughs result quickly. You end up with coils you can't fail... and the cooling just provides safety margin. Sorry, my pet subject. Done a lot of these experiments. Exciting stuff and every once in a while you make huge breakthroughs. Common to find popular theory is all wet. -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Wed, 18 Jan 2006 14:42:08 -0500 "Tracy Crook" writes: You are probably right about the post shutdown temps on cars in some conditions but passive (un powered) heat exposure is a very different thing than operating heat exposure. Keep in mind these are coil/igniter modules with electronics in the same package, not a separate module as in all Subarus (that I know of). The widely accepted semiconductor life vs temperature factor is that life is cut in half for every 10 deg C increase in temperature so it is good practice to keep them cool anyway. Having said that, the igniters I use may in fact have a problem under the conditions I run them. The LS1 Corvette igniters (made by Nippon Denso) have proven themselves reliable in aircraft service (Bill Eslick has quite a few hours using them) but I think my under cowl temps are significantly higher. This is partially by design (long cooling discussion) and partially due to the Renesis characteristics. Another factor is that I am using the LS1 truck engine version of the coils which is supposed to be electrically equivalent to the Corvette part but this may not be completely true. They are made by a different company (Hitachi I think). I have plans to do some more testing to verify their suitability. I was out of the truck parts so I replaced the dead coil with a Corvette part. In my preliminary tests, It does not look like they were overstressed by this but the coil spark rate on the rotary (at 6000 rpm) is the same as if the LS1 V8 were turning 12,000 rpm. Tracy (back from test flight after repair : ) ----- Original Message ----- From: al p wick I'm wondering if 180f under hood is really the main cause for coil fail? Auto's shut off hot in desert, black steel hood, must see temps way beyond anything we can throw at them. You can't get those puppies to fail regardless of environment. Perhaps there are one or two other significant causes. I'd be real quick to abandon that manufacturer. -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Tue, 17 Jan 2006 22:39:15 -0500 "Tracy Crook" writes: During my preflight tests this morning I found the third failed ignition coil in the last 150 hours so I finally got serious about dropping the temps around my coils and alternator. I've been concerned about this since the under-cowl temps are as high as 180 deg F (delta T through rads is 70 - 90 deg F). The attached photo shows the solution (hopefully). The alternator plenum is made from a Tupperware container pirated from the kitchen with a skirt made from sheet silicone rubber. A 5/8" ID vinyl hose routes cool air from the oil cooler plenum to it. ( 3/8" ID hose was tried first, not quite good enough) This was tried prior to today's scrubbed flight and a temp probe shows that air inlet temps to the alternator are only 3 - 5 degrees above ambient. Nice. I had recently added a cooling plenum around the coils (also made of tupperware) and fed by a 3/8" ID hose but it was pretty leaky and only dropped temps about 10 - 15 degrees. After replacing the coil today I built a better fitting plenum and fed it with 5/8" ID hose. This one is made of space-age cardboard and I'll build a more permanent one from fiberglass if it works OK. Will test tomorrow if wx allows. Input shaft Buly, got your input shaft today and checked it out. The thrust bearing rollers & races look a little stressed but the roller cage has been completely trashed. I do not think the .005" out of flatness on your bellhousing would explain this and the odd wear pattern on the plate. The marks and discoloration (heat) on the bearing and shaft look as if there is misalignment between the E-shaft and the gear drive. When you built the plate & bellhousing adapter for the drive, how did you verify concentricity? This is much harder to do than verifying the parallelism of the bellhousing and plate but is absolutely vital. There is no question that the drive would have soon failed if you had continued to run it. Glad this showed up before flight. Tracy (Happy to hear that Dave L. is safe! Good flying. ) -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html ----__JNP_000_3eff.330d.448f Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable
Your explanations sound pretty reasonable. I see these situations as = great=20 opportunity. Nothing better than when you have fairly consistent fail rate.= If=20 bench testing, this would be great time to run 1/2 from different supplier.= =20 Place insulation around 1/2 of them to induce failure. Operate at high rpm = loads=20 beyond what they can ever see. Goal is to make them all fail. Taguchi DOE=20 approach(L4 design). Sounds weird at first, but breakthroughs result = quickly.=20 You end up with coils you can't fail... and the cooling just provides = safety=20 margin. Sorry, my pet subject. Done a lot of these experiments. Exciting = stuff=20 and every once in a while you make huge breakthroughs. Common to find = popular=20 theory is all wet.
 

-al wick
Artificial intelligence in cockpit, Cozy IV powered by= =20 stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland,=20 Oregon
Prop construct, Subaru install, Risk assessment, Glass panel = design=20 info:
http:= //www.maddyhome.com/canardpages/pages/alwick/index.html
 
On Wed, 18 Jan 2006 14:42:08 -0500 "Tracy Crook" <lors01@msn.com> writes:
You are probably right about the post shutdown temps on cars in some= =20 conditions but passive (un powered) heat exposure is a very different = thing=20 than operating heat exposure.  Keep in mind these are coil/igniter=20 modules with electronics in the same package, not a separate module as in= all=20 Subarus (that I know of).  The widely accepted semiconductor life vs= =20 temperature factor is that life is cut in half for every 10 deg C = increase in=20 temperature so it is good practice to keep them cool anyway. 
 
Having said that, the igniters I use may in fact have a problem= =20 under the conditions I run them.  The LS1 Corvette igniters (= made by=20 Nippon Denso) have proven themselves reliable in aircraft service (Bill = Eslick=20 has quite a few hours using them) but I think my under cowl = temps=20 are significantly higher.  This is partially by design (long cooling= =20 discussion) and partially due to the Renesis=20 characteristics.   Another factor is that I am using = the=20 LS1 truck engine version of the coils which is supposed to be = electrically=20 equivalent to the Corvette part but this may not be completely true. = ;=20 They are made by a different company (Hitachi I think).  I have = plans to=20 do some more testing to verify their suitability.  I was out of= the=20 truck parts so I replaced the dead coil with a Corvette part. <= /DIV>
 
In my preliminary tests, It does not look like they were = overstressed by=20 this but the coil spark rate on the rotary (at 6000 rpm) is the same= =20 as if the LS1 V8 were turning 12,000 rpm.
 
Tracy (back from test flight after repair : )
----- Original Message -----
From: al p wick

I'm wondering if 180f under hood is really the main cause for coil= =20 fail? Auto's shut off hot in desert, black steel hood, must see temps = way=20 beyond anything we can throw at them. You can't get those puppies to = fail=20 regardless of environment. Perhaps there are one or two other = significant=20 causes. I'd be real quick to abandon that manufacturer.
 

-al wick
Artificial intelligence in cockpit, Cozy IV = powered by=20 stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland,= =20 Oregon
Prop construct, Subaru install, Risk assessment, Glass panel= =20 design info:
= http://www.maddyhome.com/canardpages/pages/alwick/index.html
 
On Tue, 17 Jan 2006 22:39:15 -0500 "Tracy Crook" <lors01@msn.com> writes:
During my preflight tests this morning I found the third = failed=20 ignition coil in the last 150 hours so I finally got serious about=20 dropping the temps around my coils and alternator.  
 
I've been concerned about this since the under-cowl temps = are as=20 high as 180 deg F (delta T through rads is 70 - 90 deg F). = The=20 attached photo shows the solution (hopefully).  The alternator = plenum=20 is made from a Tupperware container pirated from the kitchen with a = skirt=20 made from sheet silicone rubber.  A 5/8" ID vinyl hose routes = cool=20 air from the oil cooler plenum to it.   ( 3/8" ID hose was = tried=20 first, not quite good enough)  This was tried prior to = today's=20 scrubbed flight and a temp probe shows that air inlet temps to the=20 alternator are only 3 - 5 degrees above ambient.  Nice.
 
I had recently added a cooling plenum around the coils (also = made of=20 tupperware) and fed by a 3/8" ID hose but it was pretty leaky = and=20 only dropped temps about 10 - 15 degrees.  After replacing the = coil=20 today I built a better fitting plenum and fed it with 5/8" ID hose.&= nbsp;=20 This one is made of space-age cardboard and I'll build a more = permanent=20 one from fiberglass if it works OK.  Will test tomorrow if wx=20 allows.
 
Input shaft
 
Buly, got your input shaft today and checked it out.  The = thrust=20 bearing rollers & races look a little stressed but the roller = cage has=20 been completely trashed.  I do not think the .005" out of = flatness on=20 your bellhousing would explain this and the odd wear pattern on the=20 plate.  The marks and discoloration (heat) on the bearing and = shaft=20 look as if there is misalignment between the E-shaft  and the = gear=20 drive.  When you built the plate & bellhousing adapter for = the=20 drive, how did you verify concentricity?  This is much harder to= do=20 than verifying the parallelism of the bellhousing and plate but is=20 absolutely vital.  There is no question that the drive would = have=20 soon failed if you had continued to run it.   Glad this = showed=20 up before flight.
 
Tracy  (Happy to hear that Dave L. is safe!  Good=20 flying. )
 

-al wick
Artificial intelligence= in=20 cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on=20 engine/airframe from Portland, Oregon
Prop construct, Subaru install= ,=20 Risk assessment, Glass panel design=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html<= BR>
 

-al wick
Artificial intelligence in= =20 cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on=20 engine/airframe from Portland, Oregon
Prop construct, Subaru install, = Risk=20 assessment, Glass panel design=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
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