X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.129.170.194] (HELO VIRCOM1.fcdata.private) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4665388 for flyrotary@lancaironline.net; Wed, 05 Jan 2011 20:22:28 -0500 Received-SPF: none receiver=logan.com; client-ip=64.129.170.194; envelope-from=cbarber@texasattorney.net Received: from FCD-MAIL06.FCDATA.PRIVATE ([fe80::697f:d6aa:b87:78d8]) by FCD-MAIL05.FCDATA.PRIVATE ([fe80::809d:a06e:5913:452e%15]) with mapi id 14.01.0270.001; Wed, 5 Jan 2011 19:18:26 -0600 From: Chris Barber To: Rotary motors in aircraft Subject: Hard hot start problem possibley found. Thread-Topic: Hard hot start problem possibley found. Thread-Index: AQHLrT9XuH+24AxCzUqxoYHqdYIglQ== Date: Thu, 6 Jan 2011 01:21:39 +0000 Message-ID: <2D41F9BF3B5F9842B164AF93214F3D3034D98A15@FCD-MAIL06.FCDATA.PRIVATE> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [99.98.105.202] Content-Type: multipart/alternative; boundary="_000_2D41F9BF3B5F9842B164AF93214F3D3034D98A15FCDMAIL06FCDATA_" MIME-Version: 1.0 --_000_2D41F9BF3B5F9842B164AF93214F3D3034D98A15FCDMAIL06FCDATA_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Obviously, I am in serious need of adult supervision. That being said, I am trying to address this latest issue in as philosophic= al a manner as possible. As of late, since I got my EC2 back from Tracy, I have had a serious hot st= art issue. The engine seemed to run ok once started and seem to start pret= ty 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 engi= ne a few times keeping the rpm's very low....below about 3000 rpm. The eng= ine 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 prob= lem again. So, I thought I would start with basics again. After doing the EC2 test mo= des, I figured I would pull the plugs and have a look see. The plugs looke= d 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 ignoran= ce 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 cool= ant in the rotor housing. There was none (figured since the plugs looked g= ood). The second time I could crank the engine as watch coolant shoot acro= ss my wing....not good. So, this time, no coolant. So, I figured I would check the apex seals by l= ooking inside the spark plug holes. All three of the front seals looked go= od 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. O= ne had no real movement. The second one moved around fine but had NO sprin= giness at all. Ok, so I am "suspicious" ;-), so I break out the pressure gage. Checked th= e front chamber for sake of comparison and it gave me three nice pulses aro= und 80lbs. Did the same for the rear and it was inconsistent at 30 to 60 l= bs. 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 l= east the apex seal springs on the rear housing. Now, if any of you fine ge= ntlemen and ladies have some nice little solution that would allow me to no= t take such drastic action, I am open to such suggestion. I figured it wil= l take a few days to get new springs in the mail, so I will have time to pu= ll the engine and prepare everything. If I recall correctly, I may not hav= e 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 a= ble 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 championshi= p 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 overw= helming dismantling...guess practice makes perfect. . All the best, Chris --_000_2D41F9BF3B5F9842B164AF93214F3D3034D98A15FCDMAIL06FCDATA_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Obviously, I am in serious need of adult supervision.

 

That being said, I am trying to address this latest issue in as phi= losophical 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 o= nce 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 stat= ed 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 sta= rted 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.&nb= sp; I replaced the prop and I have the hot start problem again.

 

So, I thought I would start with basics again.  After doing the&nbs= p;EC2 test modes, I figured I would pull the plugs and= have a look see.  The plugs looked as expected (the leading plugs mor= e 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 ti= me due to my ignorance following a build of one engine from thr= ee, not having good sensors and overheating the engine.  The second time due to a brand new center housing coolan= t galley wall failing.  DOH!

 

Since I recognized the symptoms, I looked for the same issues&nbs= p;ie green coolant in the rotor housing.  There w= as none (figured since the plugs looked good).  The second time I coul= d 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 se= als by looking inside the spark plug holes.  All three of the fro= nt seals looked good and were nice and springy when I probed them ge= ntly 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 sp= ringiness at all.

 

Ok, so I am "suspicious" ;-), so I break out the pressu= re 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 a= t 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 prepar= e 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 i= t will take to put the rear housing back on, such as what parts I will remo= ve that need to be replaced and not be able to be reused.  Money is ti= ght right now, so the less the better. 

 

I may be the current leader of discovering failure modes in this al= legedly robust engine <sigh> :-) before flight. Ed, I l= eave the gliding championship to you.  I must admit that the idea of p= ulling the engine is not quite as daunting since I have moved past the proof of concept mode and have got my flight ready i= nstall pretty much set.  This makes the engine removal, and then the r= e-install much more of a methodical process than a somewhat o= verwhelming dismantling...guess practice makes perfect.  <sigh>.

 

All the best,

 

Chris

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