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 5.2.14) with ESMTP id 3634903 for flyrotary@lancaironline.net; Thu, 07 May 2009 10:45:37 -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-omta02.mail.rr.com with ESMTP id <20090507144459696.TKNU19662@cdptpa-omta02.mail.rr.com> for ; Thu, 7 May 2009 14:44:59 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: Snubber was[FlyRotary] Re: Initial Engine Startup Date: Thu, 7 May 2009 11:01:37 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0013_01C9CF03.319E76D0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Thread-Index: AcnPHnluYoIzhOiISve4Nsku3xvhngABQ0Ng In-Reply-To: Message-Id: <20090507144459696.TKNU19662@cdptpa-omta02.mail.rr.com> This is a multi-part message in MIME format. ------=_NextPart_000_0013_01C9CF03.319E76D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi Mike, Tracy gets busy as you can imagine, I'll try to answer your question about the "snubber" fix. Basically, it was discovered by a member of this list that the collapsing magnetic field of the injector coils were having a more significant effect on injector open time than first realized. In short, the injector on time was not just that commanded by the EC2/3 but was also affected by this generated voltage of the collapsing field. Since it was not a fixed thing (depending on several factors), it could make tuning a bit more of a hassle to tune - no danger of your engine quitting or anything drastic like that because you could compensate (to some extent) by your tuning and manual mixture control. But, because the effect varied - tuning was not necessarily as easy and precise as could be desired. In any case, a fix to such excursions in other fields are known as "snubber" fixes - I presume because they "Snub" out the problem. Tracy will generally automatically add the "snubber'' fix the next time you have reason to send your EC2/3 in for an upgrade. I flew for years without the fix, so it is not something you have to do immediately, but should at some point. You will likely need to retune your fuel map afterwards, so I would not spend a LOT of time doing that at this point unless you do have the "Snubber" fix. My 0.02 worth Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Fontenot Sent: Thursday, May 07, 2009 10:16 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Initial Engine Startup Tracy, You wrote: >>What was the date of last update or service? Might be able to tell about the snubber update from that.<< Here is the update info for my EC2 / EM2 combo, which was in October 2007: Looking at my manuals I see: EC2 Manual: Model: EC2 . AD Serial# 634 Date: 19-Oct-07 . On the first page of the manual, at the top it says: RWS EC2-AD Suzuki-4 ENGINE CONTROLLER 10-17-07 Page 10 has the section: MODE 2 INJECTION DYNAMIC RANGE ADJUST EM2 Manual: Model: EM2 . C3 Serial# 197 Date: 19-Oct-07 Am I Snubberfied? Has Snubberfication occurred. Is my system Snubberlicious? I need coffee. -- Mike ================================ Mike Fontenot Apex Consulting & Services LLC Lakewood, Colorado 303 / 731-6645 mikef AT apexconsultingservices DOT com ================================ ------=_NextPart_000_0013_01C9CF03.319E76D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hi = Mike,

 

Tracy gets busy as you can imagine, I’ll try to answer your question about the “snubber” = fix.

 

Basically, it was discovered by a = member of this list that the collapsing magnetic field of the injector coils = were having a more significant effect on injector open time than first realized.  In short, the injector on time was not just that = commanded by the EC2/3 but was also affected by this generated voltage of the = collapsing field.  Since it was not a fixed thing (depending on several = factors), it could make tuning a bit more of a hassle to tune – no danger of = your engine quitting or anything drastic like that because you could = compensate (to some extent) by your tuning and manual mixture control.  But, = because the effect varied – tuning was not necessarily as easy and precise = as  could be desired.

 

In any case, a fix to such = excursions in other fields are known as “snubber” fixes – I presume = because they “Snub” out the problem.  Tracy will generally automatically add the “snubber’’ fix the next time you = have reason to send your EC2/3 in for an upgrade.  =

 

I flew for years without the fix, = so it is not something you have to do immediately, but should at some = point.  You will likely need to retune your fuel map afterwards, so I would not = spend a  LOT of time doing that at this point unless you do have the = “Snubber” fix.

 

My 0.02 = worth

 

Ed

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Fontenot
Sent: Thursday, May 07, = 2009 10:16 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Initial Engine Startup

 

Tracy,
You wrote:
>>What was the date of last update or service?  Might be able = to tell about the snubber update from that.<<

Here is the update info for my EC2 / EM2 combo, which was in October = 2007:

Looking at my manuals I see:

EC2 Manual: Model: EC2 . AD   Serial# 634    = Date: 19-Oct-07   . On the first page of the manual, at the top it = says:

RWS EC2-AD Suzuki-4 ENGINE CONTROLLER  10-17-07

Page 10 has the section: MODE 2 INJECTION DYNAMIC RANGE ADJUST

EM2 Manual: Model: EM2 . C3   Serial# 197   Date: = 19-Oct-07

Am I Snubberfied? Has Snubberfication occurred. Is my system = Snubberlicious?

I need coffee.

--
Mike

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D
Mike Fontenot
Apex Consulting & Services LLC
Lakewood, = Colorado
303 / 731-6645
mikef AT apexconsultingservices DOT com
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D

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