X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.2.4) with ESMTP id 2996713 for flyrotary@lancaironline.net; Sun, 29 Jun 2008 13:06:41 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=eanderson@carolina.rr.com Received: from computername ([75.191.186.236]) by cdptpa-omta01.mail.rr.com with ESMTP id <20080629170602.CUUQ7689.cdptpa-omta01.mail.rr.com@computername> for ; Sun, 29 Jun 2008 17:06:02 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] SAG Date: Sun, 29 Jun 2008 13:06:36 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0024_01C8D9E8.F65959B0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcjZ/i4xbviKQWL5TNurHot3yGNeDQACkQ1A In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5512 Message-Id: <20080629170602.CUUQ7689.cdptpa-omta01.mail.rr.com@computername> This is a multi-part message in MIME format. ------=_NextPart_000_0024_01C8D9E8.F65959B0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit I agree with Lynn regarding SAG. Having experience SAG a number of times running on 100LL (Get an average of about 25-30 hour before SAG starts). While it certain gets your heart beat accelerated - the engine continues to run. Treat it as simply a good warning about your plug's deteriorating condition. The "good" thing about SAG is that it normally comes on gradually but continues to get worst in that the frequency of occurrence increases and the duration lengthens. The "bad" thing is it does affect power. A rotor in full SAG will drop 300F on the EGT and rpm will drop off as well (I'll hazard a guess at about 150-200 rpm). If both rotors go into SAG at the same time, it can really get your attention as you could lose around 300 rpm. I had that happen once on take off with a full load of fuel on a hot day, but even with both rotors in SAG, heavy aircraft and Hot day, I still managed 500 fpm on climbout, I was breathing hard (or hardly breathing) until I recalled, that if I got 500 fpm on a hot day while flying a Cessna 150, I thought I was doing great. So I relaxed, climbed to Altitude while circling the airport and once at altitude and pulled back on the power, the SAG went away {:>) (for a while). On one LOOOONG trip from Louisiana to North Carolina (with the plugs well over-due for change), I had SAG become a consistent plague - like every few minutes. I did discover that if I killed the spark to the Lead plugs for approx 30 sec using Tracy's EC2 ignition check switch (can only do this with controller B selected on the EC2), that the EGT would go way up but when I released the switch the SAG was gone for considerably longer. I have no clear answer as to why this would be the case, but thought I would pass it on. SAG has a bad habit of showing its face when you least want to see it. Like at full power settings - SAG on take off is not my idea of fun time, so if it's not your idea of fun, then pay heed when your spark plugs are talking to you. Spark Plugs are cheap. Also folks not using 100LL get a much larger number of hours between needing plug changes. Tracy, I know, gets over 100 hours and I think the last I heard it was closer to 200 hours. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Lynn Hanover Sent: Sunday, June 29, 2008 11:38 AM To: Rotary motors in aircraft Subject: [FlyRotary] SAG While the SAG thing might get you heart rate up there with a cross country runner, it is not fatal. It is a warning that plug fouling is ocurring, and action of some sort is required. Usually lead salts from aviation low lead fuel building up on the porcelain. This is the same as a low value resistor shunting the plug gap. So energy in the gap is reduced in increasing amounts until there is not adequate energy left to jump the gap. Starting with a small gap takes away the warning that SAG really is. The plug might be dreadfully fouled by the time it starts to miss fire, and then there is no quick fix to get home on. (if you forgot the box of new plugs and a plug wrench). With a CD or MSD system the plug will fire with a giant blob of crap building up on it. On the one hand you could say this is a great thing. But eventually you need to check the plugs as part of some maintanance program. Should the plug load up completely, the CD or MSD is not going to help you, and that plug is finished. So now the fact that it ran great and sounded good right up to the instant it quit running is not a help. I would run an MSD on the leading plugs in any case. Let the trailing plugs show you the SAG when it develops. If you are not screaming the engine, there is no need for the super small plug gaps. Then with the gaps reccomended by Mazda, SAG give you an easy fix for more hours of power if you just tighten the gaps to go home. Or better yet put in the new plugs. Tracy's system might need a load of some sort or a signal transformer to prevent damage while triggering another system instead of charging a coil primary. Lynn E. Hanover So would a smaller gap plug reduce or eliminate SAG (sparkplug attention getter)? Would a CD or MSD system eliminate it altogether? Can either work with Tracy's EC-2? Bill B ------=_NextPart_000_0024_01C8D9E8.F65959B0 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

I agree with Lynn regarding = SAG.

 

Having experience SAG a number of = times running on 100LL (Get an average of about 25-30 hour before SAG = starts).  While it certain gets your heart beat accelerated – the engine = continues to run.  Treat it as  simply a good warning about your = plug’s deteriorating condition.  The “good” thing about SAG is that it = normally comes on gradually but continues to get worst in that the frequency of = occurrence increases and the duration lengthens.  The “bad” thing = is it does affect power.  A rotor in full SAG will drop 300F on the EGT = and rpm will drop off as well (I’ll hazard a guess at about 150-200 = rpm).  If both rotors go into SAG at the same time, it can really get your = attention as you could lose around 300 rpm.  I had that happen once on take = off with a full load of fuel on a hot day, but even with both rotors in SAG, = heavy aircraft and Hot day, I still managed 500 fpm on climbout, I was = breathing hard (or hardly breathing) until I recalled, that if I got 500 fpm on a hot = day while flying a Cessna 150, I thought I was doing great.  So I = relaxed, climbed to Altitude while circling the airport and once at altitude and = pulled back on the power, the SAG went away {:>) (for a = while).

 

On one LOOOONG trip from Louisiana to North = Carolina (with the plugs well over-due for change), I had SAG become a consistent = plague – like every few minutes.  I did discover that if I killed = the spark to the Lead plugs for approx 30 sec using Tracy’s EC2 ignition = check switch (can only do this with controller B selected on the EC2), that = the EGT would go way up but when I released the switch the SAG was gone for considerably longer.  I have no clear answer as to why this would = be the case, but thought I would pass it on.

 

SAG has a bad habit of showing its = face when you least want to see it.  Like at full power settings – = SAG on take off is not my idea of fun time, so if it’s not your idea of = fun, then pay heed when your spark plugs are talking to you.  Spark = Plugs are cheap. 

 

Also folks not using 100LL get a = much larger number of hours between needing plug changes.  Tracy, I know, gets over 100 hours = and I think the last I heard it was closer to 200 = hours.

 

Ed

 

Ed Anderson

Rv-6A N494BW Rotary = Powered

Matthews, NC

eanderson@carolina.rr.com=

http://www.andersonee.com

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.dmack.net/mazda/index.html<= font size=3D2 face=3DArial>

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Lynn Hanover
Sent: Sunday, June 29, = 2008 11:38 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] = SAG

 

While = the SAG thing might get you heart rate up there with a cross country runner, it = is not fatal. It is a warning that plug fouling is ocurring, and action of some = sort is required. Usually lead salts from aviation low lead fuel building up = on the porcelain. This is the same as a low value resistor shunting the plug gap. So energy in the gap is reduced in increasing amounts until = there is not adequate energy left to jump the gap. Starting with a small gap = takes away the warning that SAG really is. The plug might be dreadfully fouled = by the time it starts to miss fire, and then there is no quick fix to get home = on. (if you forgot the box of new plugs and a plug wrench).  With a CD or = MSD system the plug will fire with a giant blob of crap building up on it. = On the one hand you could say this is a great thing. But eventually you need to = check the plugs as part of some maintanance program. Should the plug load up completely, the CD or MSD is not going to help you, and that plug is = finished. So now the fact that it ran great and sounded good right up to the = instant it quit running is not a help. 

I = would run an MSD on the leading plugs in any case. Let the trailing plugs show you = the SAG when it develops. If you are not screaming the engine, there is no need = for the super small plug gaps. Then with the gaps reccomended by Mazda, SAG = give you an easy fix for more hours of power if you just tighten the gaps to = go home. Or better yet put in the new = plugs.  

Tracy's = system might need a load of some sort or a signal transformer to prevent damage = while triggering another system instead of charging a coil primary. =

 

Lynn = E. Hanover

 

So = would a smaller gap plug reduce or eliminate SAG (sparkplug attention getter)?  = Would a CD or MSD system eliminate it altogether?  Can either work with = Tracy's = EC-2?

Bill = B 

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