X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1020434 for flyrotary@lancaironline.net; Fri, 24 Jun 2005 12:33:41 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-065-188-083-049.carolina.res.rr.com [65.188.83.49]) by ms-smtp-04-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j5OGWrL5008069 for ; Fri, 24 Jun 2005 12:32:54 -0400 (EDT) Message-ID: <000901c578da$5fa9bbd0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause Date: Fri, 24 Jun 2005 12:32:54 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01C578B8.D8615460" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0006_01C578B8.D8615460 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Georges, Yes, it was you that suggested the apex seal as the possible culprit. = Actually, the flash point of the brake fluid used is only 240F! Not much = above the boiling point of water! The brakes had been used - but, = nothing abnormal, I did not make a panic stop or such, I have put on the = binders much harder and never had a problem. But, it had to be the = brake pads and I can easily see 240F of heat being generated by them. =20 Also the brake pads always ride touching the rotor - nothing to hold = them back. I guess this does not normally cause a problem. Ed ----- Original Message -----=20 From: Echo Lake Fishing Resort (Georges Boucher)=20 To: Rotary motors in aircraft=20 Sent: Friday, June 24, 2005 12:02 PM Subject: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause Hi! Ed Nice to hear you made it back to your "honey do" list. I guess I = have to reconsider using a different fluid for brakes (contrary to my = previous posting on the subject). Do you thing over heated brakes caused = the problem? even with a leak you would need high heat to ignite the = fluid. The dropped apex seal was the only thing that made sense to me. Georges B. -------Original Message------- From: Rotary motors in aircraft Date: 06/24/05 08:02:54 To: Rotary motors in aircraft Subject: [FlyRotary] Engine Rebuild - Coolant Leak Cause Those of you who look at the Real World Solutions web site and = their latest photos may recall seeing a photo titled "Congratulations, = it's a boy" which shows coolant squirting into the air from my overflow = tank. Photo taken at Charlie's fly in. That was pretty good evidence = of a coolant leak between combustion chamber and coolant galleys and = supported by the fact that I had notice my coolant pressure increasing = on the flight to Charlies by approx 11/2 psi per hour of flight. It = started at a normal 10 psi and had increased to18 psi by the end of the = flight. =20 Well, by the time I had flown another two hours to Louisiana in = and out of rain showers, etc, back-tracking, I finally made it to my = destination. There I found that the number 1 (front) rotor would shoot = coolant out of the removed spark plug hole like old faithful when I = pulled the prop through. Clearly, had to fix the problem. Upon = opening up the engine I found two things 1. One of the triangular pieces of the apex seal was missing - = I first though it had fallen out on disassembly in my brother-in-law's = garage, but concerted search failed to locate it.=20 2. There were two "hot" spots (metal discolored to blue) on = the front rotor side housings opposite each other. One about the size = of a half dollar coin was on the side of the missing piece of the apex = seal. the second spot on the opposite housing at the same location was = smaller about the size of a quarter. It was clear looking at the "O" = rings that the heat had compromised their integrity. The appearance of = the "O" rings at that spot was as if they had shrunk in diameter. = Elsewhere the "O" rings were slightly proud of the surface of the side = housing indicating good sealing. Someone on the list suggested that the missing piece of the apex = seal might have gotten wedge at the end of the rotor and caused the = problem. At first, I was inclined to dismiss that hypothesis but = failure to find any other explanation leads me to the following = conclusion. At this point, it appears that one of the triangular pieces of = the apex seal (could not find it anywhere) left its proper position = (undoubtedly during my assembly) and got lodged at the end (apex) of one = of the rotors. May have been held their by some combination of the = corner and side seal. In any case, it appears that one area of the rotor = housing was slightly narrower than the rest (some area has to be {:>)). = Every time that rotor with the wedged piece of apex seal passed that = area it created tremendous friction and heated the side housing hot = enough for the blue discoloration. The large Hot spot was on the side of = the rotor that the piece of apex seal would normally have been. I think = the smaller Hot spot on the opposite side housing was due to the rotor = being pushed to that side by the wedged piece on the opposite side of = the rotor. So the brunt of the heat occurred where the wedged piece was = rubbing the side wall - but, at that same spot in rotation, the seal = piece forced the opposite side of the rotor into the opposite side wall = creating a smaller hot spot - but still sufficient to overheat the "O" = ring. The wedged piece probably accounts for the initial tightness of = the engine and after two hours of running it had either disintegrated or = dropped out of the housing causing the engine to loosen up. Of course, = by that time the damage to the "O" rings had been done and the results = was the slowly increasing in my coolant pressure and of course the = resulting "Congratulations, it's a boy" photo. The main point is that several folks (including Bruce T) = expressed concern when I reported the initial tightness after reassemble = from my apex seal failure on way to Sun & Fun. However, I was in a = hurry to get my aircraft off that derelict airfield and talked my self = into the notion that I had just rebuild a really "tight" engine. = Clearly, I paid for that by having to open up and correct the situation. = This time there was no tightness and the compression was even better = (guess the missing apex seal piece could account for less compression as = well). Fortunately, having friends like Laura and Tracy Crook really = helps. Laura was practically reading my mind in shipping the parts I = needed to get the engine back together. The longest time line was = simply the time required to get the parts I needed. No local source = within 60 miles was found. As always, I aim to share my experience in hopes it will = preclude someone from making the same mistakes I made. Between the brake failure/fire and the engine rebuild in = no-rotary land during the heat and humidity of a Louisiana summer, its = been one long month - but finally home and glad to be doing "Honey Dos" Best Regards Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com =20 =20 =20 ------=_NextPart_000_0006_01C578B8.D8615460 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Georges,
 
Yes, it was you that suggested the apex seal as the possible = culprit. =20 Actually, the flash point of the brake fluid used is only 240F! Not much = above=20 the boiling point of water!  The brakes had been used - but, = nothing=20 abnormal, I did not make a panic stop or such, I have put on the binders = much=20 harder and never had a problem.  But, it had to be the brake pads = and I can=20 easily see 240F of heat being generated by them. 
 
Also the brake pads always ride touching the rotor - nothing to = hold them=20 back.  I guess this does not normally cause a problem.
 
Ed
 
 
----- Original Message -----
From:=20 Echo=20 Lake Fishing Resort (Georges Boucher)
Sent: Friday, June 24, 2005 = 12:02=20 PM
Subject: [FlyRotary] Re: Engine = Rebuild -=20 Coolant Leak Cause

 Hi! Ed
Nice to hear you made it back to your "honey do" list. I = guess I=20 have to reconsider using a different fluid for brakes (contrary = to my=20 previous posting on the subject). Do you thing over heated = brakes caused=20 the problem? even with a leak you would need high heat to ignite = the=20 fluid. The dropped apex seal was the only thing that made sense = to=20 me.
Georges B.
 
-------Original=20 Message-------
 
From: Rotary motors in=20 aircraft
Date: = 06/24/05=20 08:02:54
To: Rotary motors in=20 aircraft
Subject: = [FlyRotary]=20 Engine Rebuild - Coolant Leak Cause
 

 

Those of you who look at the = Real World=20 Solutions web site and their latest photos may recall seeing a = photo=20 titled "Congratulations, it's a boy" which shows coolant = squirting into=20 the air from my overflow tank.  Photo taken at Charlie's = fly=20 in.  That was pretty good evidence of a coolant leak = between=20 combustion chamber and coolant galleys and supported by the fact = that I=20 had notice my coolant pressure increasing on the flight to = Charlies by=20 approx 11/2 psi per hour of flight. It started at a normal 10 = psi and=20 had increased to18 psi by the end of the flight.  =

Well, by the time I had flown = another two=20 hours to Louisiana in and out of rain showers, etc, = back-tracking, I=20 finally made it to my destination.  There I found that the = number 1=20 (front) rotor would shoot coolant out of the removed spark plug = hole=20 like old faithful when I pulled the prop through.  Clearly, = had to=20 fix the problem.    Upon opening up the engine I found = two=20 things

1.  One of the triangular = pieces of=20 the apex seal was missing - I first though it had fallen out on=20 disassembly in my brother-in-law's garage,  but concerted = search=20 failed to locate it.

2.  There  were two = "hot" spots=20 (metal discolored to blue) on the front rotor side housings = opposite=20 each other.  One about the size of a half dollar coin was = on the=20 side of the missing piece of the apex seal. the second spot = on the=20 opposite housing at the same location was smaller about the size = of a=20 quarter.   It was clear looking at the "O" rings that = the heat=20 had compromised their integrity.  The appearance of the "O" = rings=20 at that spot was as if they had shrunk in diameter.  = Elsewhere the=20 "O" rings were slightly proud of the surface of the side housing = indicating good sealing.

Someone on the list suggested = that the=20 missing piece of the apex seal might have gotten wedge at the = end of the=20 rotor and caused the problem.  At first, I was inclined to = dismiss=20 that hypothesis but failure to find any other explanation leads = me to=20 the following conclusion.

At this point, it = appears that one=20 of the triangular pieces of the apex seal (could not find it = anywhere)=20 left its proper position (undoubtedly during my assembly) and = got lodged=20 at the end (apex) of one of the rotors. May have been held their = by some=20 combination of the corner and side seal. In any case, it appears = that=20 one area of the rotor housing was slightly narrower than the = rest (some=20 area has to be {:>)). Every time that rotor with the wedged = piece of=20 apex seal passed that area it created tremendous friction and = heated the=20 side housing hot enough for the blue discoloration. The large = Hot spot=20 was on the side of the rotor that the piece of apex seal would = normally=20 have been. I think the smaller Hot spot on the opposite side = housing was=20 due to the rotor being pushed to that side by the wedged piece = on the=20 opposite side of the rotor. So the brunt of the heat occurred = where the=20 wedged piece was rubbing the side wall =96 but, at that same = spot in=20 rotation,  the seal piece forced the opposite side of = the=20 rotor into the opposite side wall creating a smaller hot spot = =96 but=20 still sufficient to overheat the "O" ring.

The wedged piece = probably=20 accounts for the initial tightness of the engine and after two = hours of=20 running it had either disintegrated or dropped out of the = housing=20 causing the engine to loosen up. Of course, by that time the = damage to=20 the "O" rings had been done and the results was the slowly = increasing in=20 my coolant pressure and of course the resulting = "Congratulations, it=92s a=20 boy" photo.

The main point is that several = folks=20 (including Bruce T) expressed concern when I reported the = initial=20 tightness after reassemble from my apex seal failure on way to = Sun &=20 Fun.  However, I was in a hurry to get my aircraft off that = derelict airfield and talked my self into the notion that I had = just=20 rebuild a really "tight" engine.  Clearly, I paid for that = by=20 having to open up and correct the situation.  This time = there was=20 no tightness and the compression was even better (guess the = missing apex=20 seal piece could account for less compression as = well).

Fortunately, having friends = like Laura and=20 Tracy Crook really helps.  Laura was practically reading my = mind in=20 shipping the parts I needed to get the engine back = together.  The=20 longest time line was simply the time required to get the parts = I=20 needed.  No local source within 60 miles was = found.

As always, I aim to share my = experience in=20 hopes it will preclude someone from making the same mistakes I=20 made.

Between the brake failure/fire = and the=20 engine rebuild in no-rotary land during the heat and humidity of = a=20 Louisiana summer, its been one long month - but finally home and = glad to=20 be doing "Honey Dos"

Best Regards

Ed

Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com
 
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