X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from nf-out-0910.google.com ([64.233.182.190] verified) by logan.com (CommuniGate Pro SMTP 5.1.4) with ESMTP id 1711992 for flyrotary@lancaironline.net; Sun, 24 Dec 2006 14:43:43 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.233.182.190; envelope-from=wdleonard@gmail.com Received: by nf-out-0910.google.com with SMTP id c29so4095403nfb for ; Sun, 24 Dec 2006 11:42:53 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=QOJGoBWk5dZZlq//rrAc/CPQHp9xBmmcExTyA8DuHiy8VzHl40rZ85TULfq8uHIEmd4Xep9ihhUXK8U+x8n3s7qkJHV18b6oHdh1/sb722Quyv27IOReXcGnT7xehaMX8N+1rOunWrPJCEQCSAhya2iLnBRMiuUG6vsqdbY2Rds= Received: by 10.48.48.13 with SMTP id v13mr2888834nfv.1166989373683; Sun, 24 Dec 2006 11:42:53 -0800 (PST) Received: by 10.48.215.10 with HTTP; Sun, 24 Dec 2006 11:42:53 -0800 (PST) Message-ID: <1c23473f0612241142q1fe3373cmcfd3f56205cbfc1c@mail.gmail.com> Date: Sun, 24 Dec 2006 11:42:53 -0800 From: "David Leonard" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Dead Rotor at 3000ft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_31045_4378145.1166989373372" References: ------=_Part_31045_4378145.1166989373372 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline I can testify to the resilience of Tracy's seals. When I ran my engine out of coolant, I melted the rotor housings around the spark plugs. The melted alum resulted in high rough areas affixed to the inside of the rotor housing. The apex seals were understandably marred by these rough areas, but none of them broke. That being said, I don't think you can blame the apex seals here. Sounds like maybe the spark plug is to blame, having let some of the casing float into the chamber and nick the apex seal. Joe, that temperatures are you seeing now? I have become convinced that my earlier problem with detonation and side seal failure was to to excessive average coolant temps. I frequently ran a= t 90-100C (190-210F) with frequent excursions to 110 and occasionally briefly hitting 120C. Looking back I realize that the detonation only seemed to occur when temps were 100C or higher. Also, even without detonation, the engine ran much more powerfully when temps were 80C or less. When I fly next, redline temp will be 90, and I will use the cowl flap to keep the temps at 80C. Could it be that prolonged high coolant temps contributed to your spark plug/apex seal issue? --=20 David Leonard Turbo Rotary RV-6 N4VY My websites at: http://members.aol.com/_ht_a/rotaryroster/index.html http://members.aol.com/_ht_a/vp4skydoc/index.html http://leonardiniraq.blogspot.com On 12/24/06, Ed Anderson wrote: > > Ok, Joe. As you probably recall, I lost an apex seal (two actually) on > one rotor back a couple of years ago. My conclusion was that the problem > resulted from a combination of using used rotors in which the apex seal > slots were wallowed out taking them from a vertical slot to a "V" shape. > When I took the engine apart and measured that parameter (seal slot width= ), > I found it was considerably out side the specs. I was also using Hurley > seals from Atkins. > > I surmised that the combination of the "V" slot which lost its ability to > support the side of the seal and the softer Hurley seals lead to one > fracturing and that piece taking out the following seal. So I now know > that the wear specification for that apex seal slot is something to pay > attention to. > > I went to new rotors and now use Tracy Crooks apex seals (much, much > stronger than stock or Hurley). > > Ed > > ----- Original Message ----- > *From:* Joe Hull > *To:* Rotary motors in aircraft > *Sent:* Sunday, December 24, 2006 12:00 AM > *Subject:* [FlyRotary] Re: Dead Rotor at 3000ft > > > > Thanx Ed. I'll double check but pretty sure I'm at 35. > > > > Have a very, very Merry Christmas too! (hoping the spouse and others gift > you with many aviation toys!) > > > > Joe > > > > > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Ed Anderson > *Sent:* Saturday, December 23, 2006 8:31 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Dead Rotor at 3000ft > > > > Joe, Sorry to hear about your problem but glad to hear you brought her > back safely. Does certainly appear you have a bad apex seal. You might > want to check your ignition timing. I once mistakenly (of course - who > would to it intentionally {:>)) sat my static timing to 45 deg rather tha= n > 35. I noticed while flying that If I opened up the throttle wide open th= e > note of the exhaust changed to a staccato popping. Well did not fortunat= ely > lose an apex seal but I found the center electrode ceramic cone was missi= ng > for two of the 4 plugs and cracked on the other two. Just lucky they did= n't > take out the apex seal. So you might check that timing just to be certai= n. > > > > "Merry Christmas"? > > > > Ed > > ----- Original Message ----- > > *From:* Joe Hull > > *To:* Rotary motors in aircraft > > *Sent:* Saturday, December 23, 2006 11:15 PM > > *Subject:* [FlyRotary] Dead Rotor at 3000ft > > > > The weather today in the Seattle area was marginal for flying =96 but a n= ice > hole opened around my home airport (KAWO) and I was there tinkering with = the > plane anyway (re-torqueing the prop)=96 so up I went. I did 4 touch and g= oes > just for a wee bit of practice and then departed the pattern toward a big= ger > hole that would be legal to climb through VFR. I flew about 30 miles > northwest of the airport out to the edge of the Puget Sound and enjoyed j= ust > being in the air. Power setting was about 4400RPM and I was loping along = at > a lazy 135kts. I turned around and headed back for Arlington and decided= to > ramp up the power to ramming speed =96 errr I mean cruising speed. In a f= ew > minutes I was cruising along at 170kts at about 5500RPM. Then all of a > sudden BAM =96 the engine stumbled and RPM's dropped to 2300RPM. I > immediately throttled back and switched tanks while turning toward the > airport. Altitude was 3200FT (about 3000AGL) and I was maybe 7 miles from > the airport. The engine was running real rough and wouldn't give me more > than 2300RPM. Even with that little bit of power I ended up entering the = 45 > to the pattern at about 800 above pattern altitude. It was pretty slow at > the airport so I easily made a normal landing and was able to taxi back t= o > the hanger under power. > > > > At the hangar I double checked everything I could from the cockpit =96 fu= el > pressure good at 36PSI, oil pressure good at 55PSI at 2300 RPM, MicroTech > ECM showed "OK" for the size major areas it monitors. So, I shut it down = and > pulled the cowl. I pulled the prop through a number of times and it seeme= d > that there was a couple places where I should have been hearing a "pop" i= n > the exhaust but didn't. I also notice that there is a nice ding in the pr= op > that is about an inch long =96 that wasn't there when I left (remember I'= m a > pusher). > > > > I got the engine compression gage and proceeded to take the spark plug ou= t > of the front rotor =96 top =96 BR9EQ-14. Hmmm =96 I don't remember there = being a > casing around the electrode =96 and why is that casing sliding? Apparent= ly > the casing around the electrode broke somewhere inside the sparkplug and > into two halves long ways down the electrode. Each half slides freely up = and > down the electrode and even sticks out a little from the end. > > > > I put the compression gage on and it looks like I get 30-30-70 when I tur= n > the engine over. I tried this several times and there is definitely a cou= ple > of places where it only goes to 30. So I double check the location of tha= t > ding in the prop =96 hmmm it's exactly even with the bottom of the exhaus= t =96 > right about where an apex seal would come out. > > > > I put two new BR9EQ-14's in both rotors and did a quick run =96 2300RPM > rough is the best I could get. > > > > Some time this week I'll go up and yank the exhaust so I can see the apex > seals =96 my guess is I'm missing at least one. Bummer. > > > > Joe Hull (getting tired of little surprises in the air). > > Redmond/Seattle WA, Cozy-Mazda Rotary 71hrs > > > ------------------------------ > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > > ------=_Part_31045_4378145.1166989373372 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
I can testify to the resilience of Tracy's seals.  When I ran= my engine out of coolant, I melted the rotor housings around the spark plu= gs.  The melted alum resulted in high rough areas affixed to the insid= e of the rotor housing.  The apex seals were understandably marred by = these rough areas, but none of them broke.
 
That being said, I don't think you can blame the apex seals here.&= nbsp; Sounds like maybe the spark plug is to blame, having let some of= the casing float into the chamber and nick the apex seal.
 
Joe, that temperatures are you seeing now? 
 
I have become convinced that my earlier problem with detonation and si= de seal failure was to to excessive average coolant temps.  I fre= quently ran at 90-100C (190-210F) with frequent excursions to 110 and occas= ionally briefly hitting 120C.  Looking back I realize that the detonat= ion only seemed to occur when temps were 100C or higher.  Also, even w= ithout detonation, the engine ran much more powerfully when temps were 80C = or less.  When I fly next, redline temp will be 90, and I will use the= cowl flap to keep the temps at 80C.
 
Could it be that prolonged high coolant temps contributed to your spar= k plug/apex seal issue?
 
On 12/24/06, Ed Anderson <eanderson= @carolina.rr.com> wrote:
Ok, Joe. As you probably recall, I lost an apex s= eal (two actually) on one rotor back a couple of years ago.  My conclu= sion was that the problem resulted from a combination of using used rotors = in which the apex seal slots were wallowed out taking them from a vertical = slot to a "V" shape.  When I took the engine apart and measu= red that parameter (seal slot width), I found it was considerably out side = the specs.  I was also using Hurley seals from Atkins. =20
 
I surmised that the combination of the "V&qu= ot; slot which lost its ability to support the side of the seal and the sof= ter Hurley seals lead to one fracturing and that piece taking out the follo= wing seal.   So I now know that the wear specification for that a= pex seal slot is something to pay attention to. =20
 
I went to new rotors and now use Tracy Crooks ape= x seals (much, much stronger than stock or Hurley).
 
Ed
----- Original Message -----
From: Joe Hull=
Sent: Sunday, December 24, 2006 12:0= 0 AM
Subject: [FlyRotary] Re: Dead Rotor = at 3000ft

 

Thanx Ed. I'll double check but pre= tty sure I'm at 35.

 

Have a very, very Merry Christmas t= oo! (hoping the spouse and others gift you with many aviation toys!)=

 

Joe

 

 

Joe, Sorry to hear about your problem but glad to hear you brou= ght her back safely.  Does certainly appear you have a bad apex seal.&= nbsp; You might want to check your ignition timing.  I once mistakenly= (of course - who would to it intentionally {:>)) sat my static timing t= o 45 deg rather than 35.  I noticed while flying that If I opened up t= he throttle wide open the note of the exhaust changed to a staccato popping= .  Well did not fortunately lose an apex seal but I found the center e= lectrode ceramic cone was missing for two of the 4 plugs and cracked on the= other two.  Just lucky they didn't take out the apex seal.  = So you might check that timing just to be certain.

"Merry Christmas"?

Ed

----- Original Message -----

Sent: Saturday= , December 23, 2006 11:15 PM

Subject: [FlyR= otary] Dead Rotor at 3000ft

The weather today in the Seattle area was marginal for flying = =96 but a nice hole opened around my home airport (KAWO) and I was there ti= nkering with the plane anyway (re-torqueing the prop)=96 so up I went. I di= d 4 touch and goes just for a wee bit of practice and then departed the pat= tern toward a bigger hole that would be legal to climb through VFR. I flew = about 30 miles northwest of the airport out to the edge of the Puget Sound = and enjoyed just being in the air. Power setting was about 4400RPM and I wa= s loping along at a lazy 135kts.  I turned around and headed back for = Arlington and decided to ramp up the power to ramming speed =96 errr I mean= cruising speed. In a few minutes I was cruising along at 170kts at about 5= 500RPM. Then all of a sudden BAM =96 the engine stumbled and RPM's dropped = to 2300RPM.  I immediately throttled back and switched tanks while tur= ning toward the airport. Altitude was 3200FT (about 3000AGL) and I was mayb= e 7 miles from the airport. The engine was running real rough and wouldn't = give me more than 2300RPM. Even with that little bit of power I ended up en= tering the 45 to the pattern at about 800 above pattern altitude. It was pr= etty slow at the airport so I easily made a normal landing and was able to = taxi back to the hanger under power.=20

 

At the hangar I double checked everything I could from the cock= pit =96 fuel pressure good at 36PSI, oil pressure good at 55PSI at 2300 RPM= , MicroTech ECM showed "OK" for the size major areas it monitors. So, I shu= t it down and pulled the cowl. I pulled the prop through a number of times = and it seemed that there was a couple places where I should have been heari= ng a "pop" in the exhaust but didn't. I also notice that there is a nice di= ng in the prop that is about an inch long =96 that wasn't there when I left= (remember I'm a pusher).

 

I got the engine compression gage and proceeded to take the spa= rk plug out of the front rotor =96 top =96 BR9EQ-14. Hmmm =96 I don't remem= ber there being a casing around the electrode =96 and why is that casing sl= iding?  Apparently the casing around the electrode broke somewhere ins= ide the sparkplug and into two halves long ways down the electrode. Each ha= lf slides freely up and down the electrode and even sticks out a little fro= m the end.

 

I put the compression gage on and it looks like I get 30-30-70 = when I turn the engine over. I tried this several times and there is defini= tely a couple of places where it only goes to 30. So I double check the loc= ation of that ding in the prop =96 hmmm it's exactly even with the bottom o= f the exhaust =96 right about where an apex seal would come out.

 

I put two new BR9EQ-14's in both rotors and did a quick run =96= 2300RPM rough is the best I could get.

 

Some time this week I'll go up and yank the exhaust so I can se= e the apex seals =96 my guess is I'm missing at least one. Bummer. <= /font>

 

Joe Hull (getting tired of little surprises in the air).=

Redmond/Seattle WA, Cozy-Mazda Rotary 71hrs

http://www.fl= yrotary.com/
Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/

<= br>

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