X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 26 Jan 2013 14:24:43 -0500 Message-ID: X-Original-Return-Path: Received: from nm15-vm3.bullet.mail.ne1.yahoo.com ([98.138.91.145] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTPS id 6030891 for lml@lancaironline.net; Sat, 26 Jan 2013 14:11:41 -0500 Received-SPF: none receiver=logan.com; client-ip=98.138.91.145; envelope-from=chris_zavatson@yahoo.com Received: from [98.138.90.52] by nm15.bullet.mail.ne1.yahoo.com with NNFMP; 26 Jan 2013 19:11:06 -0000 Received: from [98.138.89.173] by tm5.bullet.mail.ne1.yahoo.com with NNFMP; 26 Jan 2013 19:11:05 -0000 Received: from [127.0.0.1] by omp1029.mail.ne1.yahoo.com with NNFMP; 26 Jan 2013 19:11:05 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 971646.28883.bm@omp1029.mail.ne1.yahoo.com Received: (qmail 96786 invoked by uid 60001); 26 Jan 2013 19:11:05 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; 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Sat, 26 Jan 2013 11:11:05 PST X-Rocket-MIMEInfo: 001.001,UmFuZHksClRoYW5rcy7CoCAKwqDCoMKgwqBUaGVyZSBhcmUgdHdvIHRoaW5ncyBJIGhhdmUgYmVlbiBkb2luZyB0byBwdW1wcyB0byBlbGltaW5hdGUgdGhlIG5lZWQgZm9yICdkdW1wIHZhbHZlIHJlc2N1ZXMnLsKgIApGaXJzdCBpcyB0aGUgcmVtb3ZhbCBvZiB0aGUgcmV0dXJuIHNwcmluZ3MgdGhhdCBlbnRlcmVkIHRoZSBMZWdhY3kgcHVtcCBkZXNpZ24gaW4gYWJvdXQgMjAwNS7CoCBUaGV5wqBhZGRlZCBubyB1c2VmdWzCoGZ1bmN0aW9uYWxpdHkgYW5kwqB1bmZvcnR1bmF0ZWx5IGludHJvZHVjZWQgYSABMAEBAQE- X-Mailer: YahooMailWebService/0.8.130.494 References: X-Original-Message-ID: <1359227465.87087.YahooMailNeo@web121604.mail.ne1.yahoo.com> X-Original-Date: Sat, 26 Jan 2013 11:11:05 -0800 (PST) From: Chris Zavatson Reply-To: Chris Zavatson Subject: Re: [LML] Re: Thermal influence on Hydraulic Pressure X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-36511695-1972193974-1359227465=:87087" ---36511695-1972193974-1359227465=:87087 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Randy,=0AThanks.=A0 =0A=A0=A0=A0=A0There are two things I have been doing t= o pumps to eliminate the need for 'dump valve rescues'.=A0 =0AFirst is the = removal of the return springs that entered the Legacy pump design in about = 2005.=A0 They=A0added no useful=A0functionality and=A0unfortunately introdu= ced a lock-up failure mode.=A0 Removing the springs primarily addresses loc= k-up on the ground during thermal swings.=0AThe second thing I have been do= ing is to set the low pressure switch to 800-850 psi.=A0 This eliminates th= e gear extension lock-up mode that occasionally prevents the gear from full= y extending.=A0 The original setting was to low to overcome the pressure sp= ike that=A0propagates through the system when the gear first come out of th= e wheel wells.=0A=A0=A0=A0=A0The other thing I=A0have been doing is measuri= ng the spool resistance on every pump that comes across my desk.=A0 I haven= 't found any issues there.=A0 70g's is the typical result.=0AI have also be= en making thermal relief valves adjustable, bringing the set-point into a u= sable range (2,000 psi) for our systems.=0A=A0=0A=A0=A0=A0=A0The three-way = dump valve references in that write-up were=A0merely describing=A0the Legac= y hydraulic system.=A0=A0The Legacy cannot perform a gear free-fall extensi= on without=A0a three way valve=A0due to cylinder orientation.=A0 I still us= e=A0a two-way valve in my 360.=0AChris=0A=A0=0AChris Zavatson=0AN91CZ=0A360= std 1,400 hrs=0Ahttp://www.n91cz.net/=0A=A0=0A =0A=0A______________________= __________=0A From: randy snarr =0ATo: lml@lancairon= line.net =0ASent: Friday, January 25, 2013 5:23 AM=0ASubject: [LML] Re: The= rmal influence on Hydraulic Pressure=0A =0A=0ANice Work Chris..=0AI am hap= py to hear that I have already done what you suggested which is to install = a 3 way dump valve and run the dump line to the reservoir in a low pressure= line. It has worked very well. I dont like having to open the dump valve b= ut it is necessary once in a while especially when it is cold. The pressure= s on both sides of the system climb due to the engine heat and the gear som= etimes will not move without dumping the pressure.=0AHave you found a solut= ion for this with your research that makes the original system function wit= hout having to ever dump the pressure manually?=0A=0ARandy Snarr=0A235/320= =0AN694RS=A0=0A=0A"Flight by machines heavier than air is unpractical and i= nsignificant, if not utterly impossible"=0A-Simon Newcomb, 1902=0A =0A=0A__= ______________________________=0A From: Chris Zavatson =0ATo: lml@lancaironline.net =0ASent: Tuesday, September 4, 2012 2:18= PM=0ASubject: [LML] Re: Thermal influence on Hydraulic Pressure=0A =0A=0A= Danny, =0ANo affect on gear movement. =0AI should add however that elevated= high-side pressure is one of the contributing factors to gear extension fa= ilures in a standard system set up.=A0 My low pressure setting=A0is higher = than the nominal 550 psi.=A0=A0It is set to 800 psi to avoid the pressure s= pike that propogates through the system when gear down is selected. =0Asee = "Failure to Extend" on page 10 for more detail. =0Ahttp://www.n91cz.com/Hyd= raulics/Lancair%20Hydraulics.pdf =0A=A0 =0AChris Zavatson =0AN91CZ =0A360st= d =0Ahttp://www.n91cz.net/=A0 =0A=A0 =0A =0A=0A____________________________= ____=0AFrom: Danny =0ATo: lml@lancaironline.net =0ASent: = Monday, September 3, 2012 11:54 AM=0ASubject: [LML] Re: Thermal influence o= n Hydraulic Pressure=0A=0A=0A =0AChris, =0AWhat was the impact on the gear = movement? =0A=A0 =0ADanny =0ALNC2-360 =0AN 38=B0 43' 25.7" =0AW 77=B0 30' 3= 8.6" =0A=A0 =0AFrom:Chris Zavatson [mailto:chris_zavatson@yahoo.com] =0ASen= t: Saturday, September 01, 2012 11:32 PM=0ATo: lml@lancaironline.net=0ASubj= ect: [LML] Thermal influence on Hydraulic Pressure =0A=A0 =0A-took this pho= to after=A0a descent from 16.5k to 1,500 ft. =0AOAT=A0went from 42 to 94 de= grees. =0AHigh Pressure gauge is pegged at 2,000+ psi =0A-Didn't get a phot= o, but the opposite happened on the ramp in Spokane.=A0After sitting for an= hour, the low pressure gauge was pegged at 1,200 psi+.=A0 Spokane might no= t be the warmest spot in the country, but at 85 deg F, it was 55 degrees wa= rmer than the cold soak on the previous leg. =0ATemperature changes have a = big impact on system pressure.=A0 =0A=A0 =0AChris Zavatson =0AN91CZ =0A360s= td =0Ahttp://www.n91cz.net/ ---36511695-1972193974-1359227465=:87087 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Randy,
Thanks. 
 &n= bsp;  There are two things I have been doing to pumps to e= liminate the need for 'dump valve rescues'. 
F= irst is the removal of the return springs that entered the Legacy pump desi= gn in about 2005.  They added no useful functionality and&nb= sp;unfortunately introduced a lock-up failure mode.  Removing the spri= ngs primarily addresses lock-up on the ground during thermal swings.=
The second thing I have been doing is to set the low press= ure switch to 800-850 psi.  This eliminates the gear extension lock-up= mode that occasionally prevent= s the gear from fully extending.  The original setting was to low to overcome the pressure spike that propag= ates through the system when the gear first come out of the w= heel wells.
   &n= bsp;The other thing I have been doing is measuring the spool re= sistance on every pump that comes across my desk.  I haven't found any= issues there.  70g's is= the typical result.
I have also been making thermal= relief valves adjustable, bringing the set-point into a usable range (2,00= 0 psi) for our systems.
 
    The three-way dump val= ve references in that write-up were merely describing the Legacy = hydraulic system.  The Legacy cannot perform a gear free-fall ext= ension without a three way valve due to cylinder orientation.&nbs= p; I still use a two-way valve in my 360.
Chris
 
Chris Zavatson
N91CZ
360std 1,400 hrs
http://www.n91cz.net/=
 

From: randy snarr <randylsnarr@yahoo.com= >
To: lml@lancairon= line.net
Sent: Friday, January 25, 2013 5:2= 3 AM
Subject: [LML] Re= : Thermal influence on Hydraulic Pressure

=0A
Nice Work Chris..
I a= m happy to hear that I have already done what you suggested which is to ins= tall a 3 way dump valve and run the dump line to the reservoir in a low pre= ssure line. It has worked very well. I dont like having to open the dump valve but it is necessary once = in a while especially when it is cold. The pressures on both sides of the s= ystem climb due to the engine heat and the gear sometimes will not move wit= hout dumping the pressure.
Have you found a solut= ion for this with=0A your research that makes the original system function = without having to ever dump the pressure manually?

Randy Snarr
235/320
N694RS 
&= nbsp;
"Flight by machines hea= vier than air is unpractical and insignificant, if not utterly=0A impossible"
-Si= mon Newcomb, 1902
=
From: Chris Zavatson <chris_zavatson@yahoo.com= >
To: lml@lancairon= line.net
Sent: Tuesda= y, September 4, 2012 2:18 PM
Subj= ect: [LML] Re: Thermal influence on Hydraulic Pressure

=0A
=0A
=0A
Danny,
=0A
No affect on= gear movement.
=0A
I should add ho= wever that elevated high-side pressure is one of the contributing factors t= o gear extension failures in a standard system set up.  My low pressure setting is higher than = the nominal 550 psi.  It is set to 800 psi to avoid the pressure = spike that propogates through the system when gear down is selected.=
=0A
see "Failure to Extend" on page 10 f= or more detail.
=0A
http://www.n91= cz.com/Hydraulics/Lancair%20Hydraulics.pdf
=0A
 <= /div>=0A
Chris Zavatson
=0A
N91CZ
=0A
360std
=0A=0A
 
=0A

=0A
=0A
=0A
=0A
From: Danny <d= anny@n107sd.com>
To:= lml@lancaironline.net
Sent: Monday, September 3, 2012 11:54 AM
Subject: [LML] Re: Thermal influence on Hydraulic Pressu= re

=0A
=0A=0A=0A
=0A
=0AChris,
=0A
What was the impact on the gear move= ment?
=0A
 
=0A
=0ADanny
=0A
LNC2-360
=0A
= N 38=B0 43' 25.7"
=0A
W 77=B0 30' 38.6"
=0A
 
=0A
=0A
=0A=
<= span style=3D"font-family: Tahoma, sans-serif; font-size: 10pt; font-weight= : bold;">From: Chris Zavatson [ma= ilto:chris_zavatson@yahoo.com]
Se= nt: Saturday, September 01, 2012 11:32 PM
To: lml@lancaironline.net
Subject: [LML] Thermal influence on Hydr= aulic Pressure
=0A
 
=0A
=0A
=0A
-took this photo after a descent from 16.5k = to 1,500 ft.
=0A
=0A
OAT went from 42 to 94 degrees.
<= /div>=0A
=0A
High Pressure g= auge is pegged at 2,000+ psi
=0A
=0A
-Didn't get a photo, but the opposite hap= pened on the ramp in Spokane. After sitting for an hour, the low press= ure gauge was pegged at 1,200 psi+.  Spokane might not be the warmest = spot in the country, but at 85 deg F, it was 55 degrees warmer than the col= d soak on the previous leg.
=0A
=0A
Temperature changes have a big impact on = system pressure. 
=0A
=0A
 
=0A
=0AChris Zavatson
=
=0A
=0A
N91CZ
=0A
=0A
360= std
=0A
=0A
http://www.n91cz.net/
<= /div>





 
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