X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.3.7) with ESMTP id 4322282 for flyrotary@lancaironline.net; Fri, 21 May 2010 20:13:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=zumEJI4u4hcIJ7bW+2gKihjeYkKVorwZMM/QMKtPDvU= c=1 sm=0 a=jsIGKdKG9GkA:10 a=ADBQPqJMlbwA:10 a=Er6hwA6a1l4K/FyzC6NN7w==:17 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=7NVj1j1Y_wWXF9gmnf0A:9 a=UcO03-68R5FwGnMcT90A:7 a=k8eqqfECzxZcYfUPuxZefCLeBb0A:4 a=wPNLvfGTeEIA:10 a=1vhyWl4Y8LcA:10 a=EzXvWhQp4_cA:10 a=SSmOFEACAAAA:8 a=PHeGT7Ijg0Ql0JES_TAA:9 a=IUUXtroAkJyn4ewczdwA:7 a=OTfGcpTVPTga6ccJPj-GuRuCy5gA:4 a=Er6hwA6a1l4K/FyzC6NN7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 75.181.123.159 Received: from [75.181.123.159] ([75.181.123.159:4700] helo=computername) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id FA/8B-18491-F7127FB4; Sat, 22 May 2010 00:12:49 +0000 From: "Ed Anderson" Message-ID: To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Rear Rotor Coolant Leak Date: Fri, 21 May 2010 20:12:32 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001D_01CAF921.F36A7E00" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 In-Reply-To: Thread-Index: Acr5HfcwXmK0RixcTOO3Eb9UhxCHBAAIL0LQ X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5931 This is a multi-part message in MIME format. ------=_NextPart_000_001D_01CAF921.F36A7E00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Bobby, I presume you are using the Teflon coat silicon coolant =93O=94 = rings and not the stock Mazda ones. What I have had happen to me after sitting = for a long period (particularly in cool weather) is that apparently these = harder =93O=94 rings tend to set up or not seal as well as the softer stock = =93O=94 rings. As a consequence, I have come out to find a drop of two of green coolant hanging off my exhaust pipes. To make a long story short after pulling = the engine through a few times and then firing it up and running it up to = 160F for about 2 minutes, the problem disappeared. =20 =20 I have also found that if you do indeed have a small leak (the quantity = you mentioned suggest that) that firing up the engine perhaps permits some combustion gases to enter the coolant galley =96 this raises the = pressure in the coolant galley which turns around and pushes on the seal seating if = for a secure seal. =20 Two things to watch for =96 if you do have a serious leak into your = coolant system, your coolant pressure gauge should reflect this. After I had severely and totally cooked one of my O rings due to a hasty rebuild = that resulting in the triangular part of the apex seal ending up between = rotor and side housing =96 which created so much friction it turn the iron = housing blue for the area the size of a sliver dollar and shrunk the O ring in = that area down to little more than a tread in diameter, I still flew from = North Carolina to Mississippi. I did notice that my coolant pressure increase approx 1 psi for each 45 minutes of flight. By the time I arrived at Mississippi, the coolant pressure was up to 18 psi (temperature was = still OK). =20 =20 The system was still sealed. Around 1 hour after I landed I was at the aircraft cowl =96 off and while folks watch I popped the safety release = valve on the radiator cap and a stream of greenish liquid shot about 3 feet = into the air. So the combustion gases actually kept the seal sealing (more = or less) sufficient to make a long flight. =20 Good Luck, Bobby =20 Ed =20 =20 =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes Sent: Friday, May 21, 2010 4:45 PM To: Rotary motors in aircraft Subject: [FlyRotary] Rear Rotor Coolant Leak =20 =20 I have developed a small coolant leak in the #2 rotor of my renesis. It seems to be limited to the engine sitting for long periods of time. I discovered it when checking the plugs after the engine had not been = started for a couple of months while fitting the new supercharger. The leading = plug was wet. Pulling the prop through sprayed some coolant out of the = leading plug hole. I checked the fluid level and it was a little lower than I remember. I added some water and marked the level on a stick for = reference. The next day I check the level and found no measurable drop. Since I = had just installed the larger supercharger I decided to do a few ground runs = and check the coolant for leaks and keep a close eye on the water pressure. = I made several ground runs and everything was normal. The plane was = schedule for body work at a paint shop as soon as I could make the 50 mile trip. = I waited a few days and rechecked the fluid level. Again no measurable = drop. I then made three short flights around the airport to check out the new supercharger and kept a close eye on water pressure and temps. = Everything was normal. After checking the coolant level the next day I made the = trip to the painters. The flight was normal but the pilot was a little nervous. =20 The plane has not been started for six weeks and it sprayed maybe two tablespoons of coolant when pulling the prop through. I did not have my measuring stick but I could tell coolant level was a little lower then = the last time I had checked it.=20 =20 I will most likely have to replace the o-ring. I overheated one time = last summer during a =BE mile uphill taxi and OAT above 100F. The tarmac = temps could have been 115F. I shut the engine down when the coolant temps got = to 225F but they kept climbing. I think it took two gallons of water to = refill the system. =20 Since my water pressure is normal and does not leak down rapidly after shutdown is it possible the engine heat is sealing the O-ring ? Maybe I just need to re-torque the big bolts. =20 Bobby Hughes RV10 Renesis ------=_NextPart_000_001D_01CAF921.F36A7E00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Bobby, I presume you are using the = Teflon coat silicon coolant “O” rings and not the stock Mazda = ones.=A0 What I have had happen to me after sitting for a long period (particularly in = cool weather) is that apparently these harder “O” rings tend to = set up or not seal as well as the softer stock “O” rings.=A0 As a consequence, I have come out to find a drop of two of green coolant = hanging off my exhaust pipes.=A0 To make a long story short after pulling the engine = through a few times and then firing it up and running it up to 160F for about 2 minutes, the problem disappeared.=A0

 

I have also found that if you do = indeed have a small leak (the quantity you mentioned suggest that) that firing = up the engine perhaps permits some combustion gases to enter the coolant galley = – this raises the pressure in the coolant galley which turns around and = pushes on the seal seating if for a secure seal.

 

Two things to watch for – if = you do have a serious leak into your coolant system, your coolant pressure = gauge should reflect this.=A0 After I had severely and totally cooked one of = my O rings due to a hasty rebuild that resulting in the triangular part of the apex = seal ending up between rotor and side housing – which created so much = friction it turn the iron housing blue for the area the size of a sliver dollar = and shrunk the O ring in that area down to little more than a tread in diameter,=A0 = I still flew from North Carolina to Mississippi.=A0 I did notice that my coolant = pressure increase approx 1 psi for each 45 minutes of flight.=A0 By the time I = arrived at Mississippi, = the coolant pressure was up to 18 psi (temperature was still OK).=A0 =

 

The system was still sealed.=A0 = Around 1 hour after I landed I was at the aircraft cowl – off and while = folks watch I popped the safety release valve on the radiator cap and a stream = of greenish liquid shot about 3 feet into the air.=A0 So the combustion = gases actually kept the seal sealing (more or less) sufficient to make a long = flight.

 

Good Luck, = Bobby

 

Ed

 

 

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes
Sent: Friday, May 21, = 2010 4:45 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Rear = Rotor Coolant Leak

 

 

I have developed a small coolant leak in the #2 rotor of my = renesis. It seems to be limited to the engine sitting for long periods of time. I discovered it when checking the plugs after the engine had not been = started for a couple of months while fitting the new supercharger. The leading plug = was wet. Pulling the prop through sprayed some coolant out of the leading = plug hole. I checked the fluid level and it was a little lower than I = remember.=A0 I added some water and marked the level on a stick for reference. The next = day I check the level and found no measurable drop.=A0 Since I had just = installed the larger supercharger I decided to do a few ground runs and check the = coolant for leaks and keep a close eye on the water pressure. I made several ground = runs and everything was normal. The plane was schedule for body work at a = paint shop as soon as I could make the 50 mile trip. I waited a few days and = rechecked the fluid level. Again no measurable drop.=A0 I then made three short = flights around the airport to check out the new supercharger and kept a close eye on = water pressure and temps. Everything was normal. After checking the coolant = level the next day I made the trip to the painters. The flight was normal but the = pilot was a little nervous.

 

=A0The plane has not been started for six weeks and it sprayed = maybe two tablespoons of coolant when pulling the prop through. I did not have my measuring stick but I could tell coolant level was a little lower then = the last time I had checked it.

 

I will most likely have to replace the o-ring. I overheated one = time last summer during a =BE mile uphill taxi and OAT above 100F. The tarmac = temps could have been 115F. I shut the engine down when the coolant temps got = to 225F but they kept climbing. I think it took two gallons of water to refill = the system.

 

=A0Since my water pressure is normal and does not leak down = rapidly after shutdown is it possible the engine heat is sealing the O-ring ?=A0 Maybe = I just need to re-torque the big bolts.

 

Bobby Hughes

RV10 Renesis

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