Return-Path: <13brv3@bellsouth.net> Received: from imf25aec.mail.bellsouth.net ([205.152.59.73] verified) by logan.com (CommuniGate Pro SMTP 4.2.1) with ESMTP id 401223 for flyrotary@lancaironline.net; Tue, 07 Sep 2004 16:59:00 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.73; envelope-from=13brv3@bellsouth.net Received: from rd ([65.6.194.9]) by imf25aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20040907205832.MLPS2078.imf25aec.mail.bellsouth.net@rd> for ; Tue, 7 Sep 2004 16:58:32 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "Flyrotary List" Subject: high oil pressure and coolers Date: Tue, 7 Sep 2004 15:58:38 -0500 Message-ID: <000001c4951d$72d41b70$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C494F3.89FE1370" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C494F3.89FE1370 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Greetings, =20 I just called Bruce to ask a few questions related to oil temp and = pressure, and I'm not sure I feel better now. =20 =20 First, he still says he wouldn't run over 210F. I was of course hoping = that he's say it was OK to run more. =20 =20 Next, I was asking about how the oil pressure regulator worked, and got = an education. While this may not be news to some of you, others will find = it as disturbing as I do. The engine has two oil regulators. In my case, = the normal regulator is set at about 75 psi, and is at the inlet of the oil = to the engine. The other regulator is in the front cover, to regulate oil outlet pressure, and is fixed at 157 psi!!! This is to allow for restriction in the oil coolers and long lines. He said you'll see this = when cold, and likely during that first climbout, but he didn't believe it = would stay that high all the time. He did think it would always be over 100 = psi though. =20 I'm really concerned about the evap core in the current installation. First, it just failed, as did Dave's Setrab (rated up to 232 psi). How = many other non-Mazda oil coolers have failed? =20 =20 In my case, I have other causes for concern. My oil goes from the = engine, to the evap core, to a Peterson inline filter, back to the engine. = Along the way, I do a couple restrictive things. First, I start at AN12, then change to AN10 at the outlet of the filter. That probably causes some restriction, but perhaps not as much as the oil filter itself. The = Peterson filter is a stainless mesh filter, which normally comes with a 60 micron screen. I was concerned about that being too big, and changed to a 45 micron screen. This will certainly be more restrictive, but the = Peterson filters are very high flow to start with, so maybe this isn't an issue. Nevertheless, I'm concerned that I've caused enough restriction to make = the oil outlet pressure stay near it's 157 psi limit at high rpms. =20 =20 The next problem is not knowing what the evap core can handle. The more I've thought about it, the more I don't think the evap core routinely = sees pressures over 90-100 psi in the car. I also worry that pressure pulses = in gas are far more forgiving than they will be with liquid. Who knows if there are pulses in the oil pressure that even exceed the 232 psi rating = of the Setrab. Anyone know what the stock Mazda coolers are rated for. = =20 =20 I'm probably not going to fly again, until I have a pressure gauge on = the oil outlet of the engine, so I can read what pressure the evap core is seeing. The VDO senders seem to skip from 150 psi, to 350 psi, so = there isn't a great choice. I'm even considering not flying the evap core oil cooler again regardless. I already know it isn't going to work well = enough for my current power level, so why take a chance. =20 =20 Has anyone checked the pressure out of the engine? What do you guys = think about all this? =20 Thanks, Rusty (this is why I needed another plane) =20 =20 ------=_NextPart_000_0001_01C494F3.89FE1370 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Greetings,
 
I just called = Bruce to ask=20 a few questions related to oil temp and pressure, and I'm not sure I = feel better=20 now. 
 
First, he still = says he=20 wouldn't run over 210F.  I was of course hoping that he's say it = was OK to=20 run more. 
 
Next, I was = asking about=20 how the oil pressure regulator worked, and got an education.  While = this=20 may not be news to some of you, others will find it as disturbing as I = do. =20 The engine has two oil regulators.  In my case, the normal = regulator is set=20 at about 75 psi, and is at the inlet of the oil to the engine.  The = other=20 regulator is in the front cover, to regulate oil outlet pressure, and is = fixed=20 at 157 psi!!!  This is to allow for restriction in the oil coolers = and long=20 lines.  He said you'll see this when cold, and likely during that = first=20 climbout, but he didn't believe it would stay that high all the = time. =20 He did think it would always be over 100 psi though.
 
I'm really = concerned about=20 the evap core in the current installation.  First, it just = failed, as=20 did Dave's Setrab (rated up to 232 psi).  How many other non-Mazda = oil=20 coolers have failed? 
 
In my case, I = have other=20 causes for concern.  My oil goes from the engine, to the evap = core, to=20 a Peterson inline filter, back to the engine.  Along the way, = I do a=20 couple restrictive things.  First, I start at AN12, then = change=20 to AN10 at the outlet of the filter.  That probably causes = some=20 restriction, but perhaps not as much as the oil filter itself.  The = Peterson filter is a stainless mesh filter, which normally comes with a = 60=20 micron screen.  I was concerned about that being too big, and = changed=20 to a 45 micron screen.  This will certainly be more restrictive, = but the=20 Peterson filters are very high flow to start with, so maybe this isn't = an=20 issue.  Nevertheless, I'm concerned that I've caused enough=20 restriction to make the oil outlet pressure stay near it's 157 psi = limit at=20 high rpms.  
 
The next = problem is not=20 knowing what the evap core can handle.  The more I've thought about = it, the=20 more I don't think the evap core routinely sees pressures over 90-100 = psi in the=20 car.  I also worry that pressure pulses in gas are far = more=20 forgiving than they will be with liquid.  Who knows if there are = pulses in=20 the oil pressure that even exceed the 232 psi rating of the = Setrab.  Anyone=20 know what the stock Mazda coolers are rated=20 for.      
   =
I'm probably = not going=20 to fly again, until I have a pressure gauge on the oil outlet = of=20 the engine, so I can read what pressure the evap core is = seeing. =20  The VDO senders seem to skip from 150 psi, to 350 psi, so there = isn't a=20 great choice.  I'm even considering not flying the evap core = oil=20 cooler again regardless.  I already know it isn't going to work = well enough=20 for my current power level, so why take a chance.  =
 
Has anyone checked the pressure = out of the=20 engine?  What do you guys think about all this?
 
Thanks,
Rusty (this is why I needed = another=20 plane)
 
 
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