X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db01.mx.aol.com ([205.188.91.95] verified) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTP id 4388353 for flyrotary@lancaironline.net; Sat, 10 Jul 2010 22:40:49 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.95; envelope-from=Lehanover@aol.com Received: from imo-ma04.mx.aol.com (imo-ma04.mx.aol.com [64.12.78.139]) by imr-db01.mx.aol.com (8.14.1/8.14.1) with ESMTP id o6B2eAVw019482 for ; Sat, 10 Jul 2010 22:40:10 -0400 Received: from Lehanover@aol.com by imo-ma04.mx.aol.com (mail_out_v42.9.) id q.ce0.650f922f (43981) for ; Sat, 10 Jul 2010 22:40:07 -0400 (EDT) Received: from magic-d20.mail.aol.com (magic-d20.mail.aol.com [172.19.155.136]) by cia-dd04.mx.aol.com (v129.4) with ESMTP id MAILCIADD046-abcd4c392f07234; Sat, 10 Jul 2010 22:40:07 -0400 From: Lehanover@aol.com Message-ID: Date: Sat, 10 Jul 2010 22:40:07 EDT Subject: Re: [FlyRotary] Re: Dyno To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_e2565.6a48e04d.396a8907_boundary" X-Mailer: AOL 9.0 VR sub 5203 X-AOL-ORIG-IP: 173.88.9.178 X-AOL-IP: 172.19.155.136 X-Spam-Flag:NO X-AOL-SENDER: Lehanover@aol.com --part1_e2565.6a48e04d.396a8907_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/10/2010 8:37:57 P.M. Eastern Standard Time, ceengland@bellsouth.net writes: The points above make me ask a question I've wondered about for years. I've seen it mentioned several times that best power in a rotary is with relatively low water (or was it oil?) temps; around 160 degrees. I assume that's empirical data, & don't question it. But when the discussion turns to efficiency, I wonder if that principle (yes, I had to look up which way to spell it...) still applies. When the fuel and air are already a mixture flowing through the intake manifold, you have a target for infrared energy from the rotor face as the intake port opens. Not as bad on a side port as on a periphery port. The energy expands the mixture rapidly and so less cylinder filling results. Just air with no fuel mixed in does not suffer as much energy absorption. So the cooler the oil inside the rotor the less charge lost to heating. And injection directly into the chamber after the port has closed would be ideal. As on the proposed X-16 engine. Decades ago, I read of Japanese car manufacturers experimenting with all-ceramic engines without any cooling systems to get efficiency up by keeping the engine's heat in the combustion chamber. If we make an assumption that with synthetic oil & better quality 'soft' seal materials the rotary can be safely run at higher temps, say in the 220 degree range, would that be enough to improve BSFC? Obviously nowhere near the temps where a ceramic engine could operate, but would it be any help at all in compensating for the large swept area of the rotary combustion chamber? Charlie Racing rotaries and flying rotaries is not an exercise in efficiency. Racing engines get little over 4 MPG. Car engines are designed to be most efficient between 2,000 and 3,000 RPM where it spends nearly its entire life. A 100% efficient engine would convert every pound of fuel into work, and the engine and the exhaust temperature would remain at ambient at all times. This would mean that every BTU had been converted, and none was lost to the engine. So you see the ceramic experiments. The ceramic is a good insulator and can withstand massive heating with little loss of strength. Called adiabatic engines. See Smokey Yanuck. _http://schou.dk/hvce/_ (http://schou.dk/hvce/) Smokey lined his aluminum heads with water glass because they absorb too much heat if left stock. The object is to retain as much heat as is possible in the combustion chamber. Smokey had the same problem with the hot intake over expanding the incoming mixture, so he provided a turbo that ran at just a few pounds to maintain flow direction in the manifold. Smokey had a gag for preventing detonation in very high compression engines. Nobody found out how he did it. He let Detroit engineers drive his Mercury Capri beater with his adiabatic engine. It would not detonate even starting out in 4th gear. The intake manifold ran inside the exhaust system. Detonation is charge temperature dependant. How much fuel any particular engine needs to make each HP is a function of its design. As you lean past best power, you use less fuel, but the HP is coming down as well, and the BSFC stays about in the same area. At very low speeds where burn time is long and lean mixtures can burn completely, better BSFC is possible, but total Hp will be well down. The airplane is a dyno. Just make changes and watch the tach. Lynn E. Hanover -- --part1_e2565.6a48e04d.396a8907_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 7/10/2010 8:37:57 P.M. Eastern Standard Time,=20 ceengland@bellsouth.net writes:
The=20 points above make me ask a question I've wondered about for years.
I= 've=20 seen it mentioned several times that best power in a rotary is with=20
relatively low water (or was it oil?) temps; around 160 degrees. I= =20
assume that's empirical data, & don't question it. But when the= =20
discussion turns to efficiency, I wonder if that principle (yes, I= had=20
to look up which way to spell it...) still applies.
When the fuel and air are already a mixture flowing through the intak= e=20 manifold, you have a target for infrared energy from the rotor face as the= =20 intake port opens. Not as bad on a side port as on a periphery port. The= energy=20 expands the mixture rapidly and so less cylinder filling results. Just air= with=20 no fuel mixed in does not suffer as much energy absorption.
 
So the cooler the oil inside the rotor the less charge lost to heatin= g. And=20 injection directly into the chamber after the port has closed would be ide= al. As=20 on the proposed X-16 engine.


Decades ago, I read of Japanese car= manufacturers=20 experimenting with
all-ceramic engines without any cooling systems= to get=20 efficiency up by
keeping the engine's heat in the combustion chamber= . If=20 we make an
assumption that with synthetic oil & better quality= 'soft'=20 seal
materials the rotary can be safely run at higher temps, say in= the=20 220
degree range, would that be enough to improve BSFC? Obviously no= where=20
near the temps where a ceramic engine could operate, but would it be= any=20
help at all in compensating for the large swept area of the rotary= =20
combustion chamber?

Charlie
 
Racing rotaries and flying rotaries is not an exercise in efficiency.= =20 Racing engines get little over 4 MPG.
 
Car engines are designed to be most efficient between 2,000 and 3,000= RPM=20 where it spends nearly its entire life. A 100% efficient engine would conv= ert=20 every pound of fuel into work, and the engine and the exhaust temperature= would=20 remain at ambient at all times.
 
This would mean that every BTU had been converted, and none was lost= to the=20 engine.
So you see the ceramic experiments. The ceramic is a good insulator= and can=20 withstand massive heating with little loss of strength. Called adiabatic= =20 engines. See Smokey Yanuck.
 
 
Smokey lined his aluminum heads with water glass because they absorb= too=20 much heat if left stock.
 
The object is to retain as much heat as is possible in the combustion= =20 chamber. Smokey had the same problem with the hot intake over expanding th= e=20 incoming mixture, so he provided a turbo that ran at just a few pounds to= =20 maintain flow direction in the manifold.
 
Smokey had a gag for preventing detonation in very high compression= =20 engines. Nobody found out how he did it. He let Detroit engineers drive hi= s=20 Mercury Capri beater with his adiabatic engine. It would not detonate even= =20 starting out in 4th gear. The intake manifold ran inside the exhaust syste= m.=20 Detonation is charge temperature dependant.
 
How much fuel any particular engine needs to make each HP is a functi= on of=20 its design.
 
As you lean past best power, you use less fuel, but the HP is coming= down=20 as well, and the BSFC stays about in the same area. At very low speeds whe= re=20 burn time is long and lean mixtures can burn completely, better BSFC is=20 possible, but total Hp will be well down.
 
The airplane is a dyno. Just make changes and watch the tach.
 
Lynn E. Hanover


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