X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 931373 for flyrotary@lancaironline.net; Wed, 18 Jan 2006 10:09:42 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-01-eri0.southeast.rr.com (8.13.4/8.13.4) with SMTP id k0IF8nVU007596 for ; Wed, 18 Jan 2006 10:08:51 -0500 (EST) Message-ID: <000a01c61c41$1bb1d8d0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: LS1 Coil Failures Date: Wed, 18 Jan 2006 10:08:58 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C61C17.326BD0F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0007_01C61C17.326BD0F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hummm, think I will hold off swapping my stock Mazda Coils for the LS1s = sitting on my work bench until we have a better handle on the coil = "problem". Have now flow for 300 + hours and over six years with the = stock coils with the only problem being the early failure of the leading = module because of a resistor opening in its base. =20 The wattage of the resistor is apparently too low to carry the load of = the ignition continuously running at 6000+ rpm. Replaced the resistor = with a higher wattage one and no more problem. At least three people = have had this resistor fail using the stock coils - it may well be that = the auto folks don't design for their coils to be run at high continuous = rpms unlike the MSD type ignitions for racing.=20 I wonder what the automobile circle are experiencing with their LS1 = coils - anyone know? =20 Ed A ----- Original Message -----=20 From: al p wick=20 To: Rotary motors in aircraft=20 Sent: Wednesday, January 18, 2006 9:57 AM Subject: [FlyRotary] Re: Coil & Alt cooling, Buly's input shaft 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. =20 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 ------=_NextPart_000_0007_01C61C17.326BD0F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hummm, think I will hold off swapping = my stock=20 Mazda Coils for the LS1s sitting on my work bench until we have a better = handle=20 on the coil "problem".  Have now flow for 300 + hours and over six = years=20 with the stock coils with the only problem being the early failure of = the=20 leading module because of a resistor opening in its base.  =
 
The wattage of the resistor is = apparently too low=20 to carry the load of the ignition continuously running at 6000+ = rpm. =20 Replaced the resistor with a higher wattage one and no more = problem.  At=20 least three people have had this resistor fail using the stock coils - = it may=20 well be that the auto folks don't design for their coils to be run at = high=20 continuous rpms unlike the MSD type ignitions for = racing. 
 
I wonder what the automobile circle are = experiencing with their  LS1 coils - anyone know?
 
 
Ed A
----- Original Message -----
From:=20 al p = wick
Sent: Wednesday, January 18, = 2006 9:57=20 AM
Subject: [FlyRotary] Re: Coil = & Alt=20 cooling, Buly's input shaft

I'm wondering if 180f under hood is really the main cause for = coil fail?=20 Auto's shut off hot in desert, black steel hood, must see temps way = beyond=20 anything we can throw at them. You can't get those puppies to fail = regardless=20 of environment. Perhaps there are one or two other significant causes. = I'd be=20 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 = design=20 info:
htt= p://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 = dropping=20 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 air=20 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 only=20 dropped temps about 10 - 15 degrees.  After replacing the coil = today I=20 built a better fitting plenum and fed it with 5/8" ID hose.  = This one=20 is made of space-age cardboard and I'll build a more permanent one = from=20 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=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 soon=20 failed if you had continued to run it.   Glad this showed = up=20 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, Risk=20 assessment, Glass panel design=20 = info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
= ------=_NextPart_000_0007_01C61C17.326BD0F0--