X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-junco.atl.sa.earthlink.net ([209.86.89.63] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTP id 6001848 for flyrotary@lancaironline.net; Tue, 08 Jan 2013 20:05:49 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.63; envelope-from=n360tg@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=OX/cvZKI9sMlagl1dRPQeGj9ear+PFPPlOfgZJ/wNFeXmAG9TxIuJgmi4T7lcF+B; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [166.147.126.236] (helo=[172.20.10.2]) by elasmtp-junco.atl.sa.earthlink.net with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.67) (envelope-from ) id 1Tsk6Q-0006zr-94 for flyrotary@lancaironline.net; Tue, 08 Jan 2013 20:05:10 -0500 From: Thomas Giddings Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: multipart/alternative; boundary=Apple-Mail-1--718302571 Subject: Re: [FlyRotary] Re: HICCUP Date: Tue, 8 Jan 2013 20:05:02 -0500 In-Reply-To: To: "Rotary motors in aircraft" References: Message-Id: X-Mailer: Apple Mail (2.1085) X-ELNK-Trace: 77b0437ff618fec294f5150ab1c16ac080818c873b4a4d1ba38fa3197a5d837b79e7886bf2c5c3b5350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 166.147.126.236 --Apple-Mail-1--718302571 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Bill: FWIIW...I believe you have a Lancair...I built one many years ago = and I had a similar nagging problem with my IO360...Long story short = ...It turned out to be trash in the fuel system from building and = working on modifications . I swore it could not be...The Fix was an = stainless steel inline racing type fuel filter with removable and = cleanable 10 micron stainless filter screen. The Previous one I had = would only trap trash that was large enough to have a serial number. It = would send trash through the injector nozzles at the worst times = shutting fuel off to the cylinder(on top of over cast,over long = stretches of water)Did the filter... never missed a beat for the next = 800hrs. Probably not your problem...but might be something like that. KIND REGARDS Thomas Giddings n360tg@earthlink.net 727 858 1772 On Jan 8, 2013, at 7:39 PM, Lehanover@aol.com wrote: > Since all I can do from here is speculate, I will speculate. = Combustion upsets from ignition faults would be more than occasional. = Same for a constant too lean or too rich situation. > =20 > So, perhaps it is caused by Too hot a heat range in the spark plugs. = Try a set of Autolite AR2592 gapped at .015". Or the NGKs in dash 10 = heat range or 11.5 heat range. Yes it is very tight, but try it anyway. = Nobody will stock these plugs. Need to be an overnight order from = Autozone or similar. > =20 > Use inductive plug wires, if any. Fire both leading and trailing = together. No split timing. No low voltage ignition wires anywhere near a = high tension wire =20 > =20 > If you have a peripheral exhaust port, excessive back pressure can = occasionally force burning gasses into the intake. This causes a = profound misfire. It will not go unnoticed. A Renesis probably has no = such problem. No overlap between intake and exhaust. > =20 > A blast tube on the coils. > =20 > Reduce timing to 20 degrees. Good up to 9,000 RPM. > =20 > There was a picture of an exhaust header a few days back, where one = tube entered a down tube at a 90 degree angle. This is very bad MOJO. = Ideal header design requires two header pipes be the exact same length. = Joined at the same shallow angle (Long collector) Header lengths in = multiples of 12 inches. > =20 > If you get a misfire at full throttle, try retarding throttle slightly = to see if that cures the problem. If so, it is usually a secondary = ignition problem. > Gap the plugs tighter and try again. If the problem is cured, then the = ignition voltage is marginal for the layout in use. Gap all of the plugs = tighter all of the time or use a higher output ignition system. > =20 > The reason this gag works is this. The higher the cylinder pressure, = the more energy it takes to get a spark to jump the gap. Reducing the = throttle setting lowers cylinder filling, and cylinder pressure goes = down a bit and the plug start firing again. > =20 > The racer uses NGK R6725-11.5 The 11.5 is the heat range. The higher = the number the colder the plug (in the NGK system). > These are gapped at .010" Both leading and trailing fire together. > Both are powered by MSD6AL with rev limiters. Works great up to 10,000 = RPM. > =20 > A single rotor face misfiring is more like a thump and nothing more, > (at higher RPM) your problem sounds like a cross fire or exhaust cross = fire. Very pronounced and can cause broken apex seals and sheared off = alignment dowels or cracked out alignment dowel holes in the rear iron. = Also very bad MOJO. > =20 > Lynn E. Hanover > =20 > =20 > In a message dated 1/8/2013 4:51:54 P.M. Eastern Standard Time, = bbradburry@bellsouth.net writes: > Yes, it is happening at WOT, 2000 ft, 5800 rpm. Staging was long = past. >=20 > =20 >=20 > Bill B >=20 > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html --Apple-Mail-1--718302571 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii Bill: FWIIW...I believe you have a Lancair...I built one many years ago and I had a similar nagging problem with my IO360...Long story short ...It turned  out to be trash in the fuel system from building and working on modifications . I swore it could not be...The Fix was an stainless steel inline racing type fuel filter with removable and cleanable 10 micron stainless filter screen. The Previous one I had would only trap trash that was large enough to have a serial number. It would send trash through the injector nozzles at the worst times  shutting fuel off to the cylinder(on top of over cast,over long stretches of water)Did the filter... never missed a beat for the next 800hrs. Probably not your problem...but might be something like that.

KIND REGARDS
Thomas Giddings
727 858 1772



On Jan 8, 2013, at 7:39 PM, Lehanover@aol.com wrote:

Since all I can do from here is speculate, I will speculate. Combustion upsets from ignition faults would be more than occasional. Same for a constant too lean or too rich situation.
 
So, perhaps it is caused by Too hot a heat range in the spark plugs. Try a set of Autolite AR2592 gapped at .015". Or the NGKs in dash 10 heat range or 11.5 heat range. Yes it is very tight, but try it anyway. Nobody will stock these plugs. Need to be an overnight order from Autozone or similar.
 
Use inductive plug wires, if any. Fire both leading and trailing together. No split timing. No low voltage ignition wires anywhere near a high tension wire  
 
If you have a peripheral exhaust port, excessive back pressure can occasionally force burning gasses into the intake. This causes a profound misfire. It will not go unnoticed. A Renesis probably has no such problem. No overlap between intake and exhaust.
 
A blast tube on the coils.
 
Reduce timing to 20 degrees. Good up to 9,000 RPM.
 
There was a picture of an exhaust header a few days back, where one tube entered a down tube at a 90 degree angle. This is very bad MOJO. Ideal header design requires two header pipes be the exact same length. Joined at the same shallow angle (Long collector) Header lengths in multiples of 12 inches.
 
If you get a misfire at full throttle, try retarding throttle slightly to see if that cures the problem. If so, it is usually a secondary ignition problem.
Gap the plugs tighter and try again. If the problem is cured, then the ignition voltage is marginal for the layout in use. Gap all of the plugs tighter all of the time or use a higher output ignition system.
 
The reason this gag works is this. The higher the cylinder pressure, the more energy it takes to get a spark to jump the gap. Reducing the throttle setting lowers cylinder filling, and cylinder pressure goes down a bit and the plug start firing again.
 
The racer uses NGK R6725-11.5 The 11.5 is the heat range. The higher the number the colder the plug (in the NGK system).
These are gapped at .010" Both leading and trailing fire together.
Both are powered by MSD6AL with rev limiters. Works great up to 10,000 RPM.
 
A single rotor face misfiring is more like a thump and nothing more,
(at higher RPM) your problem sounds like a cross fire or exhaust cross fire. Very pronounced and can cause broken apex seals and sheared off alignment dowels or cracked out alignment dowel holes in the rear iron. Also very bad MOJO.
 
Lynn E. Hanover
 
 
In a message dated 1/8/2013 4:51:54 P.M. Eastern Standard Time, bbradburry@bellsouth.net writes:

Yes, it is happening at WOT, 2000 ft, 5800 rpm.  Staging was long past.

 

Bill B

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