X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-da03.mx.aol.com ([205.188.105.145] verified) by logan.com (CommuniGate Pro SMTP 6.0c1) with ESMTP id 5742336 for flyrotary@lancaironline.net; Tue, 04 Sep 2012 01:21:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.145; envelope-from=Lehanover@aol.com Received: from mtaomg-mb02.r1000.mx.aol.com (mtaomg-mb02.r1000.mx.aol.com [172.29.41.73]) by imr-da03.mx.aol.com (8.14.1/8.14.1) with ESMTP id q845LH8W026789 for ; Tue, 4 Sep 2012 01:21:17 -0400 Received: from core-moe005c.r1000.mail.aol.com (core-moe005.r1000.mail.aol.com [172.29.188.81]) by mtaomg-mb02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 16B19E000089 for ; Tue, 4 Sep 2012 01:21:17 -0400 (EDT) From: Lehanover@aol.com Message-ID: <3c3d8.61bfa27c.3d76e9cc@aol.com> Date: Tue, 4 Sep 2012 01:21:16 -0400 (EDT) Subject: Re: [FlyRotary] Re: Intermittent hiccup To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_3c3d8.61bfa27c.3d76e9cc_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [173.88.30.23] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1346736077; bh=crKc6EicHwW9Tc0l8pzvQZ3+H6BnD6oGx/FWGbytKSU=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=SEwqunWeszMY/s3WtSqHbgow0vHK0BJBxZmiogpdoeBtmf5ghggalvSAI0aAjWgO+ 2XVKMyM0bFv4fg3OBfELmshQ67BOIJZyJls+KtOquwFKlqC+48Pfbipw8cBtCc8EJe Fxw8nkDJUGPxGBR/Pb/4TpTt5Iq32AUXX4sSjNNs= X-AOL-SCOLL-SCORE: 0:2:452272640:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d294950458fcd46c0 --part1_3c3d8.61bfa27c.3d76e9cc_boundary Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en Roger on the sandblasting idea. If you have a single side electrode plug, = =20 gap it to .010" and stick it back in. If the SAG goes away, it is a plug=20 getting carbon tracks and needs discarded. If the ignition system uses 12= =20 volts to the coil primary, and an open circuit to fire the plug, ( a Kettering system) this secondary voltage break down is typical. Slow rise times alloy for a number of alternate paths to form and drain off= =20 high voltage until no spark happens. A CD system supplies 400 to 600 Volts= =20 to the primary, and the plug fires on the way up to saturation, and again= =20 during secondary collapse. So you get two hits every time. Plus so much=20 energy is available that carbon paths are burned away and the plug fires n= o=20 matter what. MSDs for 40 times at low RPM, so shorted plugs become a thing= of=20 the past. Another theory on SAG is that it is an overheated plug tip causing early = =20 firing. (preignition) which kills off torque and adds much more heat to cau= se=20 more misfires. Racing plugs are NGKR6725-11.5. The 11.5 is the heat range.= =20 The higher the number the colder the plug (In NGK plugs). Use the coldest= =20 plugs you can get to work.=20 =20 Lynn E. Hanover =20 =20 In a message dated 9/4/2012 12:02:44 A.M. Eastern Daylight Time, =20 wrjjrs@gmail.com writes: Bill, there are 2 possibilities. First you will hear from many people that = =20 you should never sandblast plugs. The reason is that the porcelain is=20 pitted and the glaze on the plug is broken and then the plugs can embed ca= rbon.=20 The plugs can then track carbon and the spark will travel down the carbon= =20 track. On fine center wire plugs blasting can round the electrode which=20 increases the voltage needed to fire the plug. Both conditions are bad,=20 tracking is the worst. Pull your plugs and look for what appears to be a p= encil=20 line down the insulator. That is tracking. It likes to hide in the area ne= ar=20 or under the sidewire which doesn't clean up as well when the blasted. Bill Jepson =20 On Sep 3, 2012 8:47 PM, "Bill Bradburry" <_bbradburry@bellsouth.net_=20 (mailto:bbradburry@bellsouth.net) > wrote: =20 =20 Has anyone ever noticed a hiccup associated with sparkplug SAG? I have a= =20 hiccup that is occurring at random intervals from seconds to several=20 minutes. Sometimes it is pretty mild and sometimes it shakes the plane! = I also =20 seem to be down in power and I am beginning to suspect plug SAG. I have= =20 38 hours with the Iridium plugs plus a lot of time over the years of runni= ng=20 the engine before flight. I had a couple instances of flooding which=20 required that I take the plugs out and sandblast them to get them to fire.= =20 Just drying them out didn=E2=80=99t work.=20 Thoughts??=20 Bill B --part1_3c3d8.61bfa27c.3d76e9cc_boundary Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
Roger on the sandblasting idea. If you have a single side electrode pl= ug,=20 gap it to .010" and stick it back in. If the SAG goes away, it is a plug ge= tting=20 carbon tracks and needs discarded. If the ignition system uses 12 volts to = the=20 coil primary, and an open circuit to fire the plug,
( a Kettering system) this secondary voltage break down is typical.
Slow rise times alloy for a number of alternate paths to form and drai= n off=20 high voltage until no spark happens. A CD system supplies 400 to 600 Volts = to=20 the primary, and the plug fires on the way up to saturation, and again duri= ng=20 secondary collapse. So you get two hits every time. Plus so much energy is= =20 available that carbon paths are burned away and the plug fires no matter wh= at.=20 MSDs for 40 times at low RPM, so shorted plugs become a thing of the past.<= /DIV>
Another theory on SAG is that it is an overheated plug tip causing ear= ly=20 firing. (preignition) which kills off torque and adds much more heat to cau= se=20 more misfires. Racing plugs are NGKR6725-11.5. The 11.5 is the heat range. = The=20 higher the number the colder the plug (In NGK plugs). Use the coldest plugs= you=20 can get to work.
 
Lynn E. Hanover
 
In a message dated 9/4/2012 12:02:44 A.M. Eastern Daylight Time,=20 wrjjrs@gmail.com writes:
=

Bill, there are 2 possibilities. First you will hear from many people = that=20 you should never sandblast plugs. The reason is that the porcelain is pit= ted=20 and the glaze on the plug is broken and then the plugs can embed carbon. = The=20 plugs can then track carbon and the spark will travel down the carbon tra= ck.=20 On fine center wire plugs blasting can round the electrode which increase= s the=20 voltage needed to fire the plug. Both conditions are bad, tracking is the= =20 worst. Pull your plugs and look for what appears to be a pencil line down= the=20 insulator. That is tracking. It likes to hide in the area near or under t= he=20 sidewire which doesn't clean up as well when the blasted.
Bill Jepson =

On Sep 3, 2012 8:47 PM, "Bill Bradburry" <bbradburry@bellsouth.net>= =20 wrote:

Has anyone e= ver=20 noticed a hiccup associated with sparkplug SAG?  I have a hiccup t= hat=20 is occurring at random intervals from seconds to several minutes. = =20 Sometimes it is pretty mild and sometimes it shakes the plane!  I = also=20 seem to be down in power and I am beginning to suspect plug SAG.  = I=20 have 38 hours with the Iridium plugs plus a lot of time over the years = of=20 running the engine before flight.  I had a couple instances of flo= oding=20 which required that I take the plugs out and sandblast them to get them= to=20 fire.  Just drying them out didn=E2=80=99t=20 work.

 

Thoughts??

 

Bill=20 B

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