X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fg-out-1718.google.com ([72.14.220.159] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2718679 for flyrotary@lancaironline.net; Wed, 06 Feb 2008 22:25:16 -0500 Received-SPF: pass receiver=logan.com; client-ip=72.14.220.159; envelope-from=wdleonard@gmail.com Received: by fg-out-1718.google.com with SMTP id e12so2620432fga.1 for ; Wed, 06 Feb 2008 19:24:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type; bh=kHtHiStRBMmafnv/GOnCYQjqQ9mXYXlKVHop8lN7sDw=; b=KRqAmgX3p7OPEP5n9roFxJqaESHyeu5/bsIe/rtnw77PzU6mF0K9zGDMKXKDO9HYXBLZGvef+iq/gJfCytbMpmihviJycpiFAdkLshqQplAHn3hAWX5gbNP1flW1smSYI7FzHc3OwypMyabuUsbEaUrqAG5HwNgXISQL7gKlczQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:mime-version:content-type; b=iQ6mPoCpxcpZ2G5AwBr7sq11reO5iuOMESpVgf9ci0VYrw/rsfMKGH1JFU41DQUd88zULPFk3xB9V13QCnSvbRZxjqeP+UpPOS8YpAQTU78O7uMe8mSbGOFKYCa2EL4qPgpKCVfI6jeXEwu/DX35zbW7FzkiGUEMn/EQZJoInFU= Received: by 10.86.78.4 with SMTP id a4mr9935061fgb.3.1202354675238; Wed, 06 Feb 2008 19:24:35 -0800 (PST) Received: by 10.86.63.9 with HTTP; Wed, 6 Feb 2008 19:24:35 -0800 (PST) Message-ID: <1c23473f0802061924m5458b636td717047c32a8b54@mail.gmail.com> Date: Wed, 6 Feb 2008 19:24:35 -0800 From: "David Leonard" To: "Rotary motors in aircraft" Subject: Idle issues solved: Was 'More Progess' MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_11320_30940137.1202354675223" ------=_Part_11320_30940137.1202354675223 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Hi Don, The manifold pulses are from the variations in pressure due to the intake cycle, I found that adding a little extra length was all I needed for the moderate benefit. I just recently discovered that when I originally did my timing, I really messed up because it seems I was running almost 40 degrees of advance. In conjunction with excessive coolant temps at the time, it is no wonder I was having problems with detonation. Now that I have moved the advance back to around 20 degrees, and never get any temps above about 170, I never come across detonation anymore (duh!). I now run up to 40" MAP for take off and usually cruise at 30". That also solved the last of my rough running at idle issues. I can now idle down below 600 rpm without missing if I want, but keep it above 1200 to avoid the gear box rattle. Regarding blow by... There should be minimal. I run my vent line down my gear leg because I do get a few drops of oil out there. But if you are getting a lot you may have a problem.. The detonation issues I was having tended to break my side seals. When that occured, I would get excessive blow by - manifest by excessive oil out the relief tube and mostly by smoke in the exhaust due to the turbo dumping oil when the case pressure started to climb. (relief is only a -4 line) My only problems now are fuel burn - I am seeing 20-50% worse fuel burn than my lyc buddies. That is likely due to excessive cooling drag and lack of refinement of timing and mixture. But I did fly up to the Mammoth (ski area) on monday and flew home the same day after a full day on the slopes. Fought a head wind in the AM but was seeing 240kts ground speed on the way home.. Cool! I true out around 180kts now adays. We skiied until the slopes closed and were home for dinner. Cool! -- David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Feb 6, 2008 11:35 AM, Don Walker wrote: > I haven't figured out the engine mis yet, but it may be somehow related > to the fact that the intake manifold pressure is all over the place. With > the top cowl off, at 3200 rpm I am getting a range of 12.6 to 13.7. With > the top of the cowl back on, it's a little higher. Can't remember exactly. > I got thinking about this and figured that there is a manifold leak. I did > pressure test it and fixed all the minor ones before I cranked it over the > first time. Then I remembered that some people had to put dampners in the > line to damper what I think are pulsations from the prop. My throttle body > is only 4 inches from the prop. Couldn't find anything in the archives > about this, so picked up 2 Brigs and straton aftermarket fuel filters to see > if this will do the job by putting them in the MAP line to the EC-2. I'll > try them out this weekend. I'm fixing the obvious stuff first and then > moving to the difficult stuff. All plugs firing well in mode 8. Still > getting the mis at all RPMs. I will see what happens after the dampners. > Anyone have any other suggestions out there? Also, I am getting a fair > amount of blowby out of the crank case breather tube at 4500rpm. What > are others doing about this. Again, nothing in the archives. > > Don Walker > RV-Renesis > N113BR > ------=_Part_11320_30940137.1202354675223 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Hi Don,

The manifold pulses are from the variations in pressure due to the intake cycle, I found that adding a little extra length was all I needed for the moderate benefit.

I just recently discovered that when I originally did my timing, I really messed up because it seems I was running almost 40 degrees of advance.  In conjunction with excessive coolant temps at the time, it is no wonder I was having problems with detonation.  Now that I have moved the advance back to around 20 degrees, and never get any temps above about 170, I never come across detonation anymore (duh!).  I now run up to 40" MAP for take off and usually cruise at 30".  That also solved the last of my rough running at idle issues.  I can now idle down below 600 rpm without missing if I want, but keep it above 1200 to avoid the gear box rattle.

Regarding blow by...  There should be minimal.  I run my vent line down my gear leg because I do get a few drops of oil out there.  But if you are getting a lot you may have a problem.. The detonation issues I was having tended to break my side seals.  When that occured, I would get excessive blow by - manifest by excessive oil out the relief tube and mostly by smoke in the exhaust due to the turbo dumping oil when the case pressure started to climb. (relief is only a -4 line)

My only problems now are fuel burn - I am seeing 20-50% worse fuel burn than my lyc buddies.  That is likely due to excessive cooling drag and lack of refinement of timing and mixture.

But I did fly up to the Mammoth (ski area) on monday and flew home the same day after a full day on the slopes.  Fought a head wind in the AM but was seeing 240kts ground speed on the way home..  Cool!   I true out around 180kts now adays.  We skiied until the slopes closed and were home for dinner.  Cool!

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net


On Feb 6, 2008 11:35 AM, Don Walker <drwalker@gbis.com> wrote:
I haven't figured out the engine mis yet, but it may be somehow related to the fact that the intake manifold pressure is all over the place.  With the top cowl off, at 3200 rpm I am getting a range of 12.6 to 13.7.  With the top of the cowl back on, it's a little higher.  Can't remember exactly.  I got thinking about this and figured that there is a manifold leak.  I did pressure test it and fixed all the minor ones before I cranked it over the first time.  Then I remembered that some people had to put dampners in the line to damper what I think are pulsations from the prop.  My throttle body is only 4 inches from the prop.  Couldn't find anything in the archives about this, so picked up 2 Brigs and straton aftermarket fuel filters to see if this will do the job by putting them in the MAP line to the EC-2.  I'll try them out this weekend.  I'm fixing the obvious stuff first and then moving to the difficult stuff.  All plugs firing well in mode 8.  Still getting the mis at all RPMs.  I will see what happens after the dampners.  Anyone have any other suggestions out there?   Also, I am getting a fair amount of blowby out of the crank case breather tube at 4500rpm.  What are others doing about this.  Again, nothing in the archives. 
 
Don Walker
RV-Renesis
N113BR


------=_Part_11320_30940137.1202354675223--