X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mailout10.ibbsonline.com ([209.55.3.207] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTPS id 4665420 for flyrotary@lancaironline.net; Wed, 05 Jan 2011 21:11:21 -0500 Received-SPF: none receiver=logan.com; client-ip=209.55.3.207; envelope-from=davidm@remconinc.com Received: from ex-relay-in03.server.ibbs.com ([10.1.200.98] helo=ex-relay-in01.server.ibbsonline.com) by mailout10.ibbsonline.com with esmtp (Exim 4.72) (envelope-from ) id 1PafJC-0000Yx-KQ; Wed, 05 Jan 2011 21:10:34 -0500 Received: from [10.1.200.58] (helo=mailout06.ibbsonline.com) by ex-relay-in01.server.ibbsonline.com with ESMTP (eXpurgate 3.1.2) (envelope-from ) id 4d25248e-7d81-0a01c83a9edd-1 for ; Wed, 05 Jan 2011 21:10:22 -0500 Received: from [75.108.190.208] (helo=[192.168.1.204]) by mailout06.ibbsonline.com with esmtp (Exim 4.72) (envelope-from ) id 1PafIz-0003Gh-Sk; Wed, 05 Jan 2011 21:10:22 -0500 Message-ID: <4D25246C.7060905@remconinc.com> Date: Wed, 05 Jan 2011 20:09:48 -0600 From: David Moyer User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101208 Thunderbird/3.1.7 MIME-Version: 1.0 To: Rotary motors in aircraft CC: Chris Barber Subject: Re: [FlyRotary] Hard hot start problem possibly found. References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------020505050200000306090807" X-DCC-IBBS-Metrics: mailout06.server.ibbs.com 1102; Body=2 Fuz1=2 Fuz2=2 X-DCC-IBBS-Result: A X-purgate-ID: 152863::1294279822-00007D81-1D911F10/0-0/0-0 X-purgate-type: clean X-purgate-size: 10788 X-purgate-Ad: Categorized by eleven eXpurgate (R) http://www.eleven.de This is a multi-part message in MIME format. --------------020505050200000306090807 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Could this have been due to the low oil level you had Chris and low oil pressure? Not too sure. I am assuming you are premixing the two-cycle oil in with the fuel. Sure wish this didn't happen to you Chris, you have had a time of it. I guess you are right you will know that engine inside and out. David Moyer On 01/05/2011 07:21 PM, Chris Barber wrote: > > Obviously, I am in serious need of adult supervision. > > That being said, I am trying to address this latest issue in > as philosophical a manner as possible. > > As of late, since I got my EC2 back from Tracy, I have had a serious > hot start issue. The engine seemed to run ok once started and seem to > start pretty easily when cold. > > A few weeks ago I thought I had an oil pressure again but as I have > stated earlier it seems that I was just low on oil. Thinking I was > going to have to pull then engine I removed my prop. Out of curiosity > I started the engine a few times keeping the rpm's very low....below > about 3000 rpm. The engine started pretty easily, even when hot, even > though it did surge until I played with the mixture. I replaced the > prop and I have the hot start problem again. > > So, I thought I would start with basics again. After doing the EC2 > test modes, I figured I would pull the plugs and have a look see. The > plugs looked as expected (the leading plugs more blackish, the > trailing more brownish, but both pair matched). > > Last time (two times actually) when I had very hard hot start it was > due to coolant leaking into the rotor housings. The first time due to > my ignorance following a build of one engine from three, not having > good sensors and overheating the engine. The second time due to a > brand new center housing coolant galley wall failing. DOH! > > Since I recognized the symptoms, I looked for the same issues ie green > coolant in the rotor housing. There was none (figured since the plugs > looked good). The second time I could crank the engine as watch > coolant shoot across my wing....not good. > > So, this time, no coolant. So, I figured I would check the apex seals > by looking inside the spark plug holes. All three of the front seals > looked good and were nice and springy when I probed them gently with a > screwdriver. So, I moved the rear housing. Uh, damn. Two of the > seals were funky. One had no real movement. The second one moved > around fine but had NO springiness at all. > > Ok, so I am "suspicious" ;-), so I break out the pressure gage. > Checked the front chamber for sake of comparison and it gave me three > nice pulses around 80lbs. Did the same for the rear and it > was inconsistent at 30 to 60 lbs. Got out some penetrant and sprayed > on the seals to no avail. Seems I have read some tricks for a stuck > apex seal, but not for one that seems to have defective/broken springs. > > So, is appears I will be pulling the engine off once again and replace > at least the apex seal springs on the rear housing. Now, if any of > you fine gentlemen and ladies have some nice little solution that > would allow me to not take such drastic action, I am open to such > suggestion. I figured it will take a few days to get new springs in > the mail, so I will have time to pull the engine and prepare > everything. If I recall correctly, I may not have to "break the seal" > to the front rotor housing at all...or so I hope. I am having to try > to remember what it will take to put the rear housing back on, such as > what parts I will remove that need to be replaced and not be able to > be reused. Money is tight right now, so the less the better. > > I may be the current leader of discovering failure modes in > this allegedly robust engine :-) before flight. Ed, I leave the > gliding championship to you. I must admit that the idea of pulling > the engine is not quite as daunting since I have moved past the proof > of concept mode and have got my flight ready install pretty much set. > This makes the engine removal, and then the re-install much more of a > methodical process than a somewhat overwhelming dismantling...guess > practice makes perfect. . > > All the best, > > Chris > --------------020505050200000306090807 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Could this have been due to the low oil level you had Chris and low oil pressure? Not too sure. I am assuming you are premixing the two-cycle oil in with the fuel. Sure wish this didn't happen to you Chris, you have had a time of it. I guess you are right you will know that engine inside and out.

David Moyer

On 01/05/2011 07:21 PM, Chris Barber wrote:

Obviously, I am in serious need of adult supervision.

 

That being said, I am trying to address this latest issue in as philosophical a manner as possible.

 

As of late, since I got my EC2 back from Tracy, I have had a serious hot start issue.  The engine seemed to run ok once started and seem to start pretty easily when cold. 

 

A few weeks ago I thought I had an oil pressure again but as I have stated earlier it seems that I was just low on oil.  Thinking I was going to have to pull then engine I removed my prop.  Out of curiosity I started the engine a few times keeping the rpm's very low....below about 3000 rpm.  The engine started pretty easily, even when hot, even though it did surge until I played with the mixture.  I replaced the prop and I have the hot start problem again.

 

So, I thought I would start with basics again.  After doing the EC2 test modes, I figured I would pull the plugs and have a look see.  The plugs looked as expected (the leading plugs more blackish, the trailing more brownish, but both pair matched). 

 

Last time (two times actually) when I had very hard hot start it was due to coolant leaking into the rotor housings.  The first time due to my ignorance following a build of one engine from three, not having good sensors and overheating the engine.  The second time due to a brand new center housing coolant galley wall failing.  DOH!

 

Since I recognized the symptoms, I looked for the same issues ie green coolant in the rotor housing.  There was none (figured since the plugs looked good).  The second time I could crank the engine as watch coolant shoot across my wing....not good.

 

So, this time, no coolant.  So, I figured I would check the apex seals by looking inside the spark plug holes.  All three of the front seals looked good and were nice and springy when I probed them gently with a screwdriver.  So, I moved the  rear housing.  Uh, damn.  Two of the seals were funky.  One had no real movement.  The second one moved around fine but had NO springiness at all.

 

Ok, so I am "suspicious" ;-), so I break out the pressure gage.  Checked the front chamber for sake of comparison and it gave me three nice pulses around 80lbs.  Did the same for the rear and it was inconsistent at 30 to 60 lbs.  Got out some penetrant and sprayed on the seals to no avail.  Seems I have read some tricks for a stuck apex seal, but not for one that seems to have defective/broken springs.

 

So, is appears I will be pulling the engine off once again and replace at least the apex seal springs on the rear housing.  Now, if any of you fine gentlemen and ladies have some nice little solution that would allow me to not take such drastic action, I am open to such suggestion.  I figured it will take a few days to get new springs in the mail, so I will have time to pull the engine and prepare everything.  If I recall correctly, I may not have to "break the seal" to the front rotor housing at all...or so I hope.  I am having to try to remember what it will take to put the rear housing back on, such as what parts I will remove that need to be replaced and not be able to be reused.  Money is tight right now, so the less the better. 

 

I may be the current leader of discovering failure modes in this allegedly robust engine <sigh> :-) before flight. Ed, I leave the gliding championship to you.  I must admit that the idea of pulling the engine is not quite as daunting since I have moved past the proof of concept mode and have got my flight ready install pretty much set.  This makes the engine removal, and then the re-install much more of a methodical process than a somewhat overwhelming dismantling...guess practice makes perfect.  <sigh>.

 

All the best,

 

Chris


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