X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet4.per.eftel.com ([203.24.100.41] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4491912 for flyrotary@lancaironline.net; Mon, 04 Oct 2010 04:35:00 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.41; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet4.per.eftel.com (Postfix) with ESMTP id B100D3BF59 for ; Mon, 4 Oct 2010 16:34:23 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id C53AEC5CEA for ; Mon, 4 Oct 2010 16:34:21 +0800 (WST) Message-ID: <460D761B336D4EA58C6E3A5286203605@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Smoking Gun -Loss of oil pressure Date: Mon, 4 Oct 2010 18:34:25 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001A_01CB63F2.C54D15F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 X-Antivirus: avast! (VPS 101003-1, 10/04/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_001A_01CB63F2.C54D15F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Lynn, If you have a picture of the Mistral modification that would be good. I don't need the info on modifying the pump, however your trumpet end on = the pick-up tube is a good idea, perhaps a bigger plate and screen would = be a good idea, as well as the baffle. Tell me does the FD have twin inlets for the oil pump, I seem to = remember something like that OR it could be something Mistral made up? = Perhaps they used the FD housing? George (down under) I'm with you on that memory thing, sadly my memory has never been = that good to start with. I digress - again. I spoke to Gordon at Mistral and they felt that = the pick-up was causing a vortex, pulling in air, that would account for = foaming. Certainly a possibility. That flat plate that the screen attaches to, = has two jobs. Hold up the screen and increases the distance from the = tube opening to the surface of the oil in the pan. This is called by = some: the vortex plate. Some are quite big in racing and seldom have a = bug screen attached. The Mazda engines have always had dismally small = vortex plates and shamefully little bug screen area. The suction tubes = are too small and no effort is made to smooth the edges of the tube = opening. I brazed on a giant thick flat washer to the end of that tube = and used a die grinder to produce a big radius into the tube end. Like a = small trumpet bell. The oil velocity at the edge of the big washer is = much lower than at the edge of the bare tube, so the washer alone cures = the vortex problem.=20 I replaced the vortex screen with one from a Pontiac. Real big. Never = a problem. That vortex problem goes South real quick if some foam gets = into the oil. So the bigger plate, or since racers use a baffle to keep = the oil in the pan, the baffle serves as the vortex plate. I ran the oil = level about 1/4" above that baffle. =20 I can't quite remember but didn't they use a 2 tube arrangement, you = mention feeding the rear rotor? They made up a real nice cover and pickup. I had a picture a couple of = computers back. If it is on a memory stick I will post it. It was a long = way to go, but it did the trick.=20 Question what is the FD twin turbo? The first model was the FA the second model was the FC and the last US = model 93-95 was the twin turbo FD. Body styles I think. I didn't know about the flat screen in the baffle plate, I just = thought it was a bigger screen, I don't know why I thought that. Why was Mistral having these problems, they weren't running the = engines hard or expecting too high HP from them. I don't know if they started out with a full baffle or not. With the = oil level just a hair below the baffle, oil from the rotors (falls out = of the center iron drain-back hole) lands on the baffle and gets a few = seconds to dump off some foam bubbles. Even with racing oil and the = baffle, there will be some foaming. So you might see the peak oil = pressure drop off about 6 to 8 pounds. Not a problem. Just normal. The = stock pump is just a bit small in displacement. Stock pressure until the = FD came along was 71.9 pounds. So, 55 to 71.9 pounds is fine from an = early engine. I like 85 from the stock pump, but you have to screw with = it too much to get it.=20 I can detail that if you want. The FD relief valve is set at 115 pounds. When the driver sprang for a real race engine $14,000.00 it had a = Peterson 3 stage dry sump pump mounted on it, so we used those for a = while. The square ones split open the pressure section, so I bought a = Moroso dry sump pump. Works great. Tall skinny reserve tank takes out = the foam. Pump is externally adjustable. Set at 100 pounds. Idle at = 2,200 RPM it has 80 pounds. At 3,000 RPM 100 pounds. Speaking of baffles, in the racer, the entire oil supply will fit in = the front cover under hard braking. The baffle eliminates this. So think = about that when doing stalls and such. Less so with the full width = mounting plate. The only 2 gages in the drivers line of sight are the = tach and oil pressure. Cars don't cruise at 6,000 RPM. Cars don't use multi grade aviation 50 = weight oil. So, in a car (or airplane with the right oil) there is no = problem. Once the oil is foamed and starts to overheat (air in the oil = is an insulator) so the coolers quit working, and the oil quits cooling = the things oil is supposed to cool. A little air gets that vortex thing = started. Very bad mojo. Never leave the pattern bad mojo. We should remember that very available non synthetic racing oils have = extra anti-scuff zink compounds, and anti foaming additives. A straight weight racing oil (No polymer = strings) burns clean enough for rotary use. If you get all of your top = oil as a premix, you can use a 40 wt. synthetic racing oil in the sump, = and get the anti scuff, the anti foam and astounding film strength. Or = you could install one of Richard Sohn's gizmos and run a synthetic = racing oil in the sump, and an ash free 2 cycle top oil through the OMP. = No premixing at all.=20 Tracy sells them for Sohn. I would premix just a bit anyway. The later OMP lines favored the apex = seals and not the side seals.=20 Why is it no one else is having these problems OR should they be = anticipating problems.=20 Well we all have to on guard for the Spanish inquisition, and Obama, = but mostly, it's because everyone reads this forum, and that other one, = and knows that at least 1/3 of the total cooling required is going to be = oil cooling. Start off with too much cooling and add additional cooling = from there. Lots of this data is in Racing Beats catalogue. Available for free = down load from their web site. You can download the Mazda Competition manual from the "Nopistons" web = site for free. Lots of good stuff there about computer maps. Dyno = passes. Water injection and so-on. George (down under) There you go. Lynn E. Hanover ------=_NextPart_000_001A_01CB63F2.C54D15F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Lynn,
If you have a = picture=20 of the Mistral modification that would be=20 good.
I don't need = the info=20 on modifying the pump, however your trumpet end on the pick-up tube is a = good=20 idea, perhaps a bigger plate and screen would be a good idea, as well as = the=20 baffle.
Tell me does = the FD=20 have twin inlets for the oil pump, I seem to remember something = like that=20 OR it could be something Mistral made up? Perhaps they used the FD=20 housing?
George (down=20 under)
I'm with = you on=20 that memory thing, sadly my memory has never been that good to start = with.
 
I digress = - again.  I spoke to Gordon at Mistral and they felt that = the=20 pick-up was causing a vortex, pulling in air, that would account for = foaming.
Certainly a possibility. That flat plate that the screen = attaches=20 to, has two jobs. Hold up the screen and increases the distance = from the=20 tube opening to the surface of the oil in the pan. This is called = by=20 some: the vortex plate. Some are quite big in racing and seldom have a = bug=20 screen attached. The Mazda engines have always had dismally small = vortex=20 plates and shamefully little bug screen area. The suction tubes are = too small=20 and no effort is made to smooth the edges of the tube opening. I = brazed on a=20 giant thick flat washer to the end of that tube and used a die grinder = to=20 produce a big radius into the tube end. Like a small trumpet bell. The = oil=20 velocity at the edge of the big washer is much lower than at the edge = of the=20 bare tube, so the washer alone cures the vortex problem. =
 
I replaced the vortex screen with one from a = Pontiac. Real=20 big. Never a problem. That vortex problem goes South real quick = if some=20 foam gets into the oil. So the bigger plate, or since racers use a = baffle to=20 keep the oil in the pan, the baffle serves as the vortex plate. I ran = the oil=20 level about 1/4" above that baffle.  
 
I can't quite remember but didn't = they use a 2=20 tube arrangement, you mention feeding the rear=20 rotor?
They made up a real nice cover and pickup. I had a = picture a=20 couple of computers back. If it is on a memory stick I will post it. = It was a=20 long way to go, but it did the trick.
 
Question=20 what is the FD twin turbo?
 
The first model was the FA the second model was the FC = and the=20 last US model 93-95 was the twin turbo FD.
Body styles I think.
I didn't = know about=20 the flat screen in the baffle plate, I just thought it was a bigger = screen,=20 I don't know why I thought that.
 
Why was = Mistral=20 having these problems, they weren't running the engines hard or = expecting=20 too high HP from = them.
I don't know if they started out with a full baffle or = not. With=20 the oil level just a hair below the baffle, oil from the rotors (falls = out of=20 the center iron drain-back hole) lands on the baffle and gets a few = seconds to=20 dump off some foam bubbles. Even with racing oil and the baffle, there = will be=20 some foaming. So you might see the peak oil pressure drop off about 6 = to 8=20 pounds. Not a problem. Just normal. The stock pump is just a bit small = in=20 displacement. Stock pressure until the FD came along was 71.9 pounds. = So, 55=20 to 71.9 pounds is fine from an early engine. I like 85 from the stock = pump,=20 but you have to screw with it too much to get it.
 
I can detail that if you want.
 
The FD relief valve is set at 115 pounds.
 
When the driver sprang for a real race engine $14,000.00 = it had a=20 Peterson 3 stage dry sump pump mounted on it, so we used those for a = while.=20 The square ones split open the pressure section, so I bought a Moroso = dry sump=20 pump. Works great. Tall skinny reserve tank takes out the foam. Pump = is=20 externally adjustable. Set at 100 pounds. Idle at 2,200 RPM it has 80 = pounds.=20 At 3,000 RPM 100 pounds.
 
Speaking of baffles, in the racer, the entire oil supply = will fit=20 in the front cover under hard braking. The baffle eliminates this. So = think=20 about that when doing stalls and such. Less so with the full width = mounting=20 plate. The only 2 gages in the drivers line of sight are the tach = and oil=20 pressure.
 
Cars don't cruise at 6,000 RPM. Cars don't use multi = grade=20 aviation 50 weight oil. So, in a car (or airplane with the right oil) = there is=20 no problem. Once the oil is foamed and starts to overheat (air in the = oil is=20 an insulator) so the coolers  quit working, and the oil quits = cooling the=20 things oil is supposed to cool. A little air gets that vortex thing = started.=20 Very bad mojo. Never leave the pattern bad mojo.
 
We should remember that very available non synthetic = racing oils=20 have extra anti-scuff zink compounds,
and anti foaming additives. A straight weight racing oil = (No=20 polymer strings) burns clean enough for rotary use. If you get all of = your top=20 oil as a premix, you can use a 40 wt. synthetic racing oil in the = sump, and=20 get the anti scuff, the anti foam and astounding film strength. Or you = could=20 install one of Richard Sohn's gizmos and run a synthetic racing oil in = the=20 sump, and an ash free 2 cycle top oil through the OMP. No premixing at = all.=20
 
Tracy sells them for Sohn.
 
I would premix just a bit anyway. The later OMP lines = favored the=20 apex seals and not the side seals.
Why is it = no one=20 else is having these problems OR should they be anticipating = problems.=20
Well we all have to on guard for = the Spanish=20 inquisition, and Obama, but mostly, it's because=20 everyone reads this forum, and that = other one,=20 and knows that at least 1/3 of the total cooling required is going to = be oil=20 cooling. Start off with too much cooling and add additional cooling = from=20 there.
 
Lots of this data is in Racing Beats catalogue. Available = for=20 free down load from their web site.
 
You can download the Mazda Competition manual from the=20 "Nopistons" web site for free. Lots of good stuff there about computer = maps.=20 Dyno passes. Water injection and so-on.
 
George = (down=20 under)
 
There you go.
 
Lynn E. Hanover
 
 
 
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