Return-Path: Received: from mailout2.pacific.net.au ([61.8.0.85] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 593098 for flyrotary@lancaironline.net; Thu, 06 Jan 2005 04:07:15 -0500 Received-SPF: none receiver=logan.com; client-ip=61.8.0.85; envelope-from=peon@pacific.net.au Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout2.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with ESMTP id j0696hHn004305 for ; Thu, 6 Jan 2005 20:06:43 +1100 Received: from ar1 (ppp2D83.dyn.pacific.net.au [61.8.45.131]) by mailproxy1.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with SMTP id j0696aj8018640 for ; Thu, 6 Jan 2005 20:06:37 +1100 Message-ID: <002901c4f3ce$dfd55850$832d083d@ar1> From: "Leon" To: "Rotary motors in aircraft" References: Subject: Some things to check was Re: [FlyRotary] Acceptable oil pressure Date: Thu, 6 Jan 2005 20:05:30 +1100 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0026_01C4F42B.124E29E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_0026_01C4F42B.124E29E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi John, Don't have my REW FD engine manual here at home (Don't want to quote = figures off the top of my head). However, 60 PSI seems OK at those revs = (4,000). What do you get up around 5,500 - 6,000 RPM? That's the = critical issue. Anyway, will get back to you when I have consulted the = manual. (Anybody else got an FD workshop manual handy?). =20 It's not really the pressure that matters so much as the ability of the = pump to supply sufficient volume. The FD pump is quite big, and has the = capacity to pump enormous volumes of oil. As somebody else said, it's = designed to feed two turbos, so it shouldn't have a problem feeding one = turbo plus the PSRU. I'm currently running in a Series V turbo engine. It is mild ported, = and has a tricked up early model dismantleable style regulator. It will = produce 100 PSI above 6,000 RPM, but it has about the same PSI as you = have at the lower RPM ranges, once the engine is warmed up. Again, I = don't have any of my manuals here so I can't tell you exactly what to = expect from the different stock reguilators. Apart from a leaky pickup gasket, or if the bolts were left finger = tight (you have to be REAL careless to have this happen) it is possible = to have a fractured oil pickup pipe (rare but it can happen), I've also = seen blokes leave the oil pump bolts loose (again usually finger = tight!), or not stake the oil pump shaft lock washer (just = carelessness), or the Woodruff key wasn't located correctly (Ed's = issue! - REAL easy to do - happens to me about every second or third = engine). Sometimes it takes two or three goes to get it in. They are = real small & fiddly You must ALWAYS double check - use strong light or a = torch to make sure that you can see the key is in the correct place once = the sprocket in on on the shaft, before fitting the nut & lockwasher. =20 I also assume you used the white nylon backup ring that goes with the O = ring on the outlet from the front housing to the front cover?? I also = assume that you used the correct O ring?? Early (pre '85) engines just = has the O ring and the gasket. I've had these blow out at times ( = usually with tricked regulators in race engines). I developed a = technique where I stopped using front cover gaskets for this reason. = Just a much thinner O ring and RTV sliastic. Never had a failure since. = But all this is a thing of the past with "86 on engines. Mazda got = smart, and used the nylon back up ring to contain the O ring, instead = of just the gasket material. One operational thing we have found in race cars is that if the sump is = overfilled, and/or we are not using a baffle plate (a sheet of alloy = that goes between the sump & the bottom of the motor), the oil can get = whipped into a "milkshake" (emulsion) by the front counter weight. The = emulsified oil will cause the pump to cavitate, and then you get = fluctuating/dropping oil pressure. So make sure you have the correct = length dipstick, and the sump is not over-filled. =20 I think all aero engines should have an alloy baffle plate. During = descent, the engine is still turning at reasonable RPM, even though = the throttle might be nearly closed. Oil in the sump will tend to = migrate up into the front cover (just like a car under brakes). If the = counterwieght gets a chance, it will take great delight in making a = caramel or chocolate (depending on how clean the oil is) milkshake out = of your lubricant. If you happen to need to get back on the noise in a = hurry, you might just have oil pressure problems. Anyway, there's my baker's dozen or so Brass Razoos for today. Cheers, Leon ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Thursday, January 06, 2005 1:26 PM Subject: [FlyRotary] Acceptable oil pressure Leon and anyone else who cares to comment... The remaining question with my installation is whether the oil = pressure is acceptable, or whether something actually wrong. Everything has been triple calibrated now, so I'm pretty sure of the = following readings..... Start-up at 70F ambient gets me 80 - 85PSI. Once the oil gets hot I'm = seeing about 15 or so at idle, 25 PSI at 2000 rpm, 45 PSI at 3500 rpm, = and maybe 60 PSI at 4000. Talking about today with Tracy he felt it was = marginal, and was wondering if this might be normal with a combination = of a turbo and a redrive both taking pressure. Other possible causes he = suggested were Ed's spinning shaft syndrome or air being sucked by a = leaking oil pickup.=20 I hate to remove the engine (again) to check these items. What do people think? Anything else I can check? John (no more soot on the prop) ------=_NextPart_000_0026_01C4F42B.124E29E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi John,
 
Don't have my REW FD engine manual here = at home=20 (Don't want to quote figures off the top of my head). However,  60 = PSI=20 seems OK at those revs (4,000).  What do you get up around = 5,500 -=20 6,000 RPM?  That's the critical issue. Anyway,  will get = back to=20 you when I have consulted the manual.  (Anybody else got an FD = workshop=20 manual handy?). 
 
It's not really the pressure that = matters so much=20 as the ability of the pump to supply sufficient volume. The FD pump = is=20 quite big,  and has the capacity to pump enormous volumes of=20 oil.   As somebody else said,  it's designed to feed two=20 turbos,  so it shouldn't have a problem feeding one turbo plus the=20 PSRU.
 
I'm currently running in a Series V = turbo=20 engine.  It is mild ported,  and has a tricked up early model=20 dismantleable style regulator.  It will produce 100 PSI above = 6,000=20 RPM,  but it has about the same PSI as you have at the lower RPM=20 ranges,  once the engine is warmed up. Again,  I don't = have any=20 of my manuals here so I can't tell you exactly what to expect from the = different=20 stock reguilators.
 
Apart from a leaky pickup gasket,  = or if the=20 bolts were left finger tight (you have to be REAL careless to have this=20 happen)  it is possible to have a fractured oil pickup = pipe (rare=20 but it can happen),  I've also seen blokes leave the oil pump bolts = loose=20 (again usually finger tight!),  or not stake the oil pump shaft = lock washer=20 (just carelessness),  or the Woodruff key wasn't located correctly = (Ed's=20 issue! - REAL easy to do - happens to me about every second or third=20 engine).  Sometimes it takes two or three goes to get it = in. They=20 are real small & fiddly You must ALWAYS double check = - use=20 strong light or a torch to make sure that you can see the key is in the=20 correct place once the sprocket in on on the shaft,  = before=20 fitting the nut & lockwasher. 
 
I also assume you used the white nylon = backup ring=20 that goes with the O ring on the outlet from the front housing to the = front=20 cover??  I also assume that you used the correct O ring??  = Early (pre=20 '85) engines just has the O ring and the gasket.  I've had these = blow out=20 at times ( usually with tricked regulators in race engines). I = developed a=20 technique where I stopped using front cover gaskets for this = reason.  Just=20 a much thinner O ring and RTV sliastic.  Never had a failure=20 since. But all this is a thing of the past with "86 on=20 engines.  Mazda got smart,  and used the nylon back up ring to = contain=20 the O ring,   instead of just the gasket = material.
 
One operational thing we have = found in race=20 cars is that if the sump is overfilled,  and/or we are not using a = baffle=20 plate (a sheet of alloy that goes between the sump & the bottom of = the=20 motor),  the oil can get whipped into a "milkshake" (emulsion) by = the front=20 counter weight.  The emulsified oil will cause the pump to = cavitate, =20 and then you get fluctuating/dropping oil pressure.  So make sure = you have=20 the correct length dipstick,  and the sump is not = over-filled. =20
 
I think all aero engines should have an = alloy=20 baffle plate.  During descent,  the engine is still turning at = reasonable RPM,  even though the throttle might be nearly = closed.  Oil=20 in the sump will tend to migrate up into the front cover (just like a = car under=20 brakes).  If the counterwieght gets a chance,  it will take = great=20 delight in making a caramel or chocolate (depending on how = clean the=20 oil is)  milkshake out of your lubricant.  If you happen = to need=20 to get back on the noise in a hurry,  you might just have oil = pressure=20 problems.
 
Anyway,  there's my baker's dozen = or so Brass=20 Razoos for today.
 
Cheers,
 
Leon
----- Original Message -----
From:=20 John=20 Slade
Sent: Thursday, January 06, = 2005 1:26=20 PM
Subject: [FlyRotary] Acceptable = oil=20 pressure

Leon = and anyone=20 else who cares to comment...
 
The = remaining=20 question with my installation is whether the oil pressure is = acceptable, or=20 whether something actually wrong.
Everything has=20 been triple calibrated now, so I'm pretty sure of the following=20 readings.....
 
Start-up at 70F=20 ambient gets me 80 - 85PSI.  Once the oil gets hot I'm seeing = about 15 or=20 so at idle, 25 PSI at 2000 rpm, 45 PSI at 3500 rpm, and maybe 60 PSI = at=20 4000.  Talking about today with Tracy he felt it was = marginal, and=20 was wondering if this might be normal with a combination of a = turbo and a=20 redrive both taking pressure.  Other possible causes he suggested = were=20 Ed's spinning shaft syndrome or air being sucked by a leaking oil = pickup.=20
 
I = hate to remove=20 the engine (again) to check these items.
 
What = do people=20 think? Anything else I can check?
 
John = (no more soot=20 on the prop)
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