X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 06 Jun 2008 15:50:44 -0400 Message-ID: X-Original-Return-Path: Received: from mta9.adelphia.net ([68.168.78.199] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with ESMTP id 2956054 for lml@lancaironline.net; Fri, 06 Jun 2008 08:16:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=68.168.78.199; envelope-from=super_chipmunk@roadrunner.com Received: from Laptop ([74.75.176.139]) by mta9.adelphia.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with SMTP id <20080606121944.YCKL4520.mta9.adelphia.net@Laptop> for ; Fri, 6 Jun 2008 08:19:44 -0400 X-Original-Message-ID: <0E994E6026A24A0E89516032222C93CE@Laptop> From: "Bill Wade" X-Original-To: "Lancair Mailing List" References: In-Reply-To: Subject: Re: [LML] Crankcase pressure=OIL ON BELLY/Photos X-Original-Date: Fri, 6 Jun 2008 08:16:00 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0055_01C8C7AD.8E270290" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6001.18000 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18000 This is a multi-part message in MIME format. ------=_NextPart_000_0055_01C8C7AD.8E270290 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ----- Original Message -----=20 From: Steve Colwell=20 To: lml@lancaironline.net=20 Sent: Thursday, June 05, 2008 9:35 PM Subject: [LML] Crankcase pressure=3DOIL ON BELLY/Photos Bill, =20 Thanks for the ideas, I have been doing some further testing....... =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Bill Wade =20 Steve- I run an IO-550-B. The installation is FWF from an A-36 = Bonanza and though I didn't do the installation everything was reused = that could be. The vent tubing is aluminum with only short hose sections = for coupling. It runs upward from the filler tube, over the oil cooler = and through the baffling before it turns down and wanders over to the = cowl flap. It appears to be above the filler cap at the highest point. = Someone could check me on this but I'd guess that was the arrangement = used by Beech, possibly to counter a problem like yours. The engine has = 2K total time, about 400 hrs since top overhaul, [oil] pressure is 60#. = I use 9 quarts (12 qt capacity) and apart from a slight mist off the = front seal it stays squeaky clean. Almost nothing comes out the vent = tube. If you have a Legacy, can you give me a measurement of the exit = end of your crankcase breather? The easiest reference could be the = lower left motor mount hole in the firewall. How much higher? How far = to the right? I have the IO-550 in a Navion- I'm building a IV-P. I can't help you = with the routing in a Legacy but I thought the way my installation was = done might give you some ideas. =20 From your picture that doesn't seem to be an option but would it be = possible to gain height by going over the #2 intake or upward aft of the = baffle so that any oil might separate and drain back to the filler? I = have not tried to get the vent tube higher since the exit from the = dipstick housing is fairly high and the top of the cowl would not allow = me to get more than =BD" or so higher. I figured there wouldn't be much room inside the cowling but again, = based on what I see on my plane, it might be worth trying. =20 =20 Does the bit of aluminum tape in the upper photo cover a previous = routing hole? The tape covers a "Anti-siphon hole" I added after the = problem began at the suggestion of ECI the cylinder manufacturer. It = was taped off in the photo for a test and has been tried open and closed = in several tests. In the upper photo it looks like there's a hole in the baffle that's = been covered over with aluminum tape- it looked to be about the right = size for a vent line. =20 I had also been thinking that you might have excessive pressure = inside your lower cowling. I'm trying to explain the manometer change at = 120KT- perhaps the outlet size is adequate up to that point but not = enough to allow increased flow at higher speeds. Since your vent tube = terminates inside the cowling that might pressurize the crankcase. I = wouldn't expect it to cause oil to blow out the breather though- it = might come from somewhere else if that was the case. I finally have a = glimmer of hope. I relocated the crankcase vent exit about 2" above the = original location and 3/4" further from the centerline of the cowl exit. = In a quick trip around the pattern the belly had only a thin film of = oil rather than a thick coat. The suggestion from a friend (who managed = the service dept. for the Cessna dealer in Sacramento) was to move the = vent exit away from the low pressure area caused by venturi effect at = the cowl exit. I measured the pressure difference between the original = location and the most recent one with a 2" increase on the manometer. Interesting- my vent terminates right at the cowl flap. So it = could've been actively sucking oil out of the engine? =20 You have checked for leakage extensively although initially you were = wondering whether there might be leakge from the alternator etc. From = that I guess you had oil all over the rear of the engine? I notice the = vent tube ends quite a bit above the bottom of the firewall. Air = currents inside the cowling can spread oil from even a small leak all = over the place and there's a long way for the vent oil to exit. Early = on, I washed the engine down with solvent to check the source of the = leak, it is all coming from the breather. =20 =20 I'd suggest a temporay extension outside the cowling to see what that = might do. The whistle hole should also be closed off. At the very least = that'd eliminate lower cowling pressure as a factor and any flow from = the vent would go straight onto the belly so you'd have a chance to see = if there was leakage from anywhere else. Also, if there's any way to = have oil drain back into the filler it might help a lot. I removed a = Andair Air/Oil Separator for testing to keep it from masking the = results. The plan is to put it back in the system to minimize oil loss = when I am sure what is going on. =20 How much time on the engine and who built It? It is a Performance = Engine with about 50 hours, stock 9:1 compression and magnetos, Ron = Monson has been very helpful. =20 My best guesses- Bill Wade Mine too-Steve Colwell Good luck, hope you get it straightened out. -Bill __________ NOD32 3142 (20080528) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com ------=_NextPart_000_0055_01C8C7AD.8E270290 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
----- Original Message -----
From:=20 Steve=20 Colwell
Sent: Thursday, June 05, 2008 = 9:35=20 PM
Subject: [LML] Crankcase = pressure=3DOIL ON=20 BELLY/Photos

Bill,

 

Thanks=20 for the ideas, I have been doing some further=20 testing=85=85=85=85=85..

 

From: Lancair = Mailing=20 List [mailto:lml@lancaironline.net] On Behalf Of Bill=20 Wade

 

Steve-

        =20 I run an IO-550-B. The installation is FWF from an A-36 Bonanza and = though I=20 didn't do the installation everything was reused that could be. The = vent=20 tubing is aluminum with only short hose sections for=20 coupling. It runs upward from the filler tube, over the oil = cooler and=20 through the baffling before it turns down and wanders over to the cowl = flap.=20 It appears to be above the filler cap at the highest point. Someone = could=20 check me on this but I'd guess that was the arrangement used by Beech, = possibly to counter a problem like yours. The engine has 2K total = time, about=20 400 hrs since top overhaul, [oil] = pressure is=20 60#. I use 9 quarts (12 qt capacity) and apart from a slight = mist=20 off the front seal it stays squeaky clean. Almost nothing comes = out the=20 vent tube. If you = have a=20 Legacy, can you give me a measurement of the exit end of your = crankcase=20 breather?  The easiest reference could be the lower left motor = mount hole=20 in the firewall.  How much higher?  How far to the = right?

  I have the IO-550 in a Navion- I'm building a = IV-P. I can't=20 help you with the routing in a Legacy but I thought the way my = installation=20 was done might give you some ideas.

 

 From your=20 picture that doesn't seem to be an option but would it be possible to = gain=20 height by going over the #2 intake or upward aft of the baffle so = that=20 any oil might separate and drain back to the filler? I=20 have not tried to get the vent tube higher since the exit from the = dipstick=20 housing is fairly high and the top of the cowl would not allow me to = get more=20 than =BD=94 or so higher.

  I figured there wouldn't be = much room=20 inside the cowling but again, based on what I see on my plane, it = might be=20 worth trying. 

 

Does the = bit=20 of aluminum tape in the upper photo cover a previous routing = hole?  The tape = covers a=20 =93Anti-siphon hole=94 I added after the problem began at the = suggestion of ECI=20 the cylinder manufacturer.  It was taped off in the photo for a = test and=20 has been tried open and closed in several tests.

  In the upper photo it looks like there's a = hole in the=20 baffle that's been covered over with aluminum tape- it looked to be = about the=20 right size for a vent line.

 

 I = had also=20 been thinking that you might have excessive pressure inside your lower = cowling. I'm trying to explain the manometer change at 120KT-=20 perhaps the outlet size is adequate up to that point but not = enough=20 to allow increased flow at higher speeds. Since your vent tube = terminates=20 inside the cowling that might pressurize the crankcase. I = wouldn't=20 expect it to cause oil to blow out the breather though- it might come = from=20 somewhere else if that was the case. =20 I=20 finally have a glimmer of hope.  I relocated the crankcase vent = exit=20 about 2=94 above the original location and 3/4=94 further from the = centerline of=20 the cowl exit.  In a quick trip around the pattern the belly had = only a=20 thin film of oil rather than a thick coat.  The suggestion from a = friend=20 (who managed the service dept. for the Cessna dealer in Sacramento) = was to=20 move the vent exit away from the low pressure area caused by venturi = effect at=20 the cowl exit.  I measured the pressure difference between the = original=20 location and the most recent one with a 2=94  increase on the=20 manometer.

 =20 Interesting- my vent terminates right = at the cowl=20 flap. So it could've been actively sucking oil out of the=20 engine?

 

 You = have=20 checked for leakage extensively although initially you = were wondering=20 whether there might be leakge from the alternator etc. From that = I guess=20 you had oil all over the rear of the engine?=20 I notice the vent tube ends quite a bit above the bottom of the = firewall. Air currents inside the cowling can spread oil from even a = small=20 leak all over the place and there's a long way for the vent oil to = exit. =20 Early=20 on, I washed the engine down with solvent to check the source of the = leak, it=20 is all coming from the breather.

 

 

 I'd = suggest a=20 temporay extension outside the cowling to see what that might do. The = whistle=20 hole should also be closed off. At the very least that'd eliminate = lower=20 cowling pressure as a factor and any flow from the vent would go = straight onto=20 the belly so you'd have a chance to see if there was leakage from = anywhere=20 else. Also, if there's any way to have oil drain back into the = filler it=20 might help a lot.  = I removed = a Andair=20 Air/Oil Separator for testing to keep it from masking the = results.  The=20 plan is to put it back in the system to minimize oil loss when I am = sure what=20 is going on.

 

  = How much=20 time on the engine and who built It? =20 It is a = Performance=20 Engine with about 50 hours, stock 9:1 compression and magnetos, Ron = Monson has=20 been very helpful.

 

 

  My = best=20 guesses-  Bill Wade

Mine = too-Steve=20 Colwell

  = Good luck, hope you get it straightened = out. =20 -Bill



__________ NOD32 3142 (20080528) = Information=20 __________

This message was checked by NOD32 antivirus = system.
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