X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTP id 4365555 for flyrotary@lancaironline.net; Mon, 21 Jun 2010 17:47:12 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id A6B861735BB for ; Tue, 22 Jun 2010 05:46:33 +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 CD146BEC032 for ; Tue, 22 Jun 2010 05:46:32 +0800 (WST) Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: 13B rotary engines Date: Tue, 22 Jun 2010 07:46:40 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0021_01CB11DF.0D4647C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5931 X-Antivirus: avast! (VPS 100621-1, 06/21/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0021_01CB11DF.0D4647C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Bill, What you say is true but a little misleading. It's true that idle is = affected - at maybe below 2,00 engine RPM (700 prop rpm). Some have had = it lower without problems. The power is governed by the p-port sizing and the manifold tube sizing. = If it's a big racing (2"+) power won't come in until higher RPM because = of lower inlet velocity and therefore lower VE. If the P-ort is sized to = the power RPM, the velocity is up, the VE is up and the power is up. From my limited knowledge. George ( down under) I recommend you wait and see how Mark Steitle comes out with his setup = first. He already says he would probably not go this route again. He = is having problems with idle, which Lynn pretty much explains with the = overlap of the intake/exhaust. Also even with the MT prop, Mark is = having trouble getting rpms up to the range that Lynn says the PP engine = works best at. We would like to get 7K rpm on take off and climb, but = the balance of operation will be in the 5-6K rpm range. Lynn says the = PP doesn't start to kick in till 7K+. =20 The rpm problem is a conundrum with the MT prop. If you assume the = prop is going into fine pitch, and the gearbox is not binding, and the = engine is not going lean, and the timing is correct, it would seem that = he should be able to rev to the same 7500 or higher rpm that he was = going to originally. =20 By the way, Mark, I was doing some calculations to see what the prop = pitch would have to be to get your speed, and discovered a discrepancy = in your reported rpms. You said 5200 engine, 1700 prop. That wont work = with the 2.85 ratio??? Can you tell us more? Maybe someone can help = you troubleshoot. =20 Bill B =20 -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Bryan Winberry Sent: Monday, June 21, 2010 12:23 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: 13B rotary engines =20 All this talk of additional power coupled with an easier intake design = has me thinking I should probably go this direction with my Renesis. = It's still on the stand after rebuild. I haven't constructed the manifold yet anyway. =20 I assume fuel flow will be higher than normal? =20 Is slide throttle best option? =20 Need to search archives I guess. =20 Good info Lynn, Thanks =20 Bryan =20 =20 =20 =20 -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Lynn Hanover Sent: Monday, June 21, 2010 12:15 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: 13B rotary engines =20 In a message dated 6/21/2010 11:03:01 A.M. Eastern Standard Time, = rv-4mike@cox.net writes: Thanks for the feedback Lynn. Unusual to see a "poor port design" = actually aid performance. =20 Mike Wills =20 =20 It is not obvious until you start graphing the open and close events, = but the side port which uses the side of the rotor as a shutter to open = and close the port, offers Mazda great latitude in port timing. In the = periphery ported engine (both ports) it is impossible to arrive at zero = overlap, and have an engine that will produce any power at all. The apex = seal does not close off either port at all, it just valves gasses in one = direction or another.=20 =20 In addition, the overlap of the periphery ported engine is far more = effective flow wise than overlap in the side ported engine. One apex = seal is above the intake port when the opposing apex seal is below the = exhaust port. Flow between the two is unobstructed. =20 So, at low RPM you get fresh mixture leaving through the exhaust port, = and combinations of burned and unburned fuel and exhaust gasses flowing = partway back into the intake runners. =20 This reduces the low RPM output to the point that the engine seems = quit docile, and is easy to drive around in the car, slowly, or possibly = taxi in an aircraft. This would make off idle tuning data useless as = there will be fuel burning right on top of the EGT probes, and unburned = fuel reaching the F/A sensor. =20 =20 The engine will act along the lines of a piston engine with a long = duration cam. When the engine reaches its happy RPM where all of the = mixture is burning inside the engine, it will step up on the "CAM" and = you will see what a good idea this was. Use slow throttle inputs until = you find the "WOW" RPM, and be ready with all available rudder.=20 =20 When we first ran a factory periphery port engine, we found that there = were places on the track that would not allow full throttle. This with = 11" wide slicks. Thank Heaven for rev limiters. The driver reported the = rear end getting real loose cresting hills and bumps. =20 Why yes it was.......... =20 Lynn E. Hanover=20 ------=_NextPart_000_0021_01CB11DF.0D4647C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Bill,
What you say is true but a little = misleading. It's=20 true that idle is affected - at maybe below 2,00 engine RPM  (700 = prop=20 rpm). Some have had it lower without problems.
The power is governed by the p-port = sizing and the=20 manifold tube sizing. If it's a big racing (2"+) power won't come = in until=20 higher RPM because of lower inlet velocity and therefore lower VE. If = the P-ort=20 is sized to the power RPM, the velocity is up, the VE is up and the = power is=20 up.
From my limited knowledge.
George ( down under)

I recommend = you wait=20 and see how Mark Steitle comes out with his setup first.  He = already says=20 he would probably not go this route again.  He is having problems = with=20 idle, which Lynn pretty much explains with the = overlap of=20 the intake/exhaust.  Also even with the MT prop, Mark is having = trouble=20 getting rpms up to the range that Lynn says the PP engine works best = at. =20 We would like to get 7K rpm on take off and climb, but the balance of=20 operation will be in the 5-6K rpm range.  Lynn says the PP doesn=92t start to = kick in=20 till 7K+.

 

The rpm = problem is a=20 conundrum with the MT prop.  If you assume the prop is going into = fine=20 pitch, and the gearbox is not binding, and the engine is not going = lean, and=20 the timing is correct, it would seem that he should be able to rev to = the same=20 7500 or higher rpm that he was going to=20 originally.

 

By the way, = Mark, I=20 was doing some calculations to see what the prop pitch would have to = be to get=20 your speed, and discovered a discrepancy in your reported rpms.  = You said=20 5200 engine, 1700 prop.  That wont work with the 2.85 = ratio???  Can=20 you tell us more?  Maybe someone can help you=20 troubleshoot.

 

Bill=20 B

 

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bryan Winberry
Sent: Monday, June 21, 2010 = 12:23=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: 13B = rotary=20 engines

 

All this = talk of=20 additional power coupled with an easier intake design has me thinking = I should=20 probably go this direction with my Renesis.  It=92s still on the = stand=20 after rebuild.

I haven=92t = constructed=20 the manifold yet anyway.

 

I assume = fuel flow=20 will be higher than normal?

 

Is slide = throttle=20 best option?

 

Need to = search=20 archives I guess.

 

Good info = Lynn,=20 Thanks

 

Bryan

 

 

 

 

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Lynn Hanover
Sent: Monday, June 21, 2010 = 12:15=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: 13B = rotary=20 engines

 

In a message dated 6/21/2010 11:03:01 A.M. = Eastern=20 Standard Time, rv-4mike@cox.net=20 writes:

Thanks = for the=20 feedback Lynn. Unusual to see a "poor port = design"=20 actually aid performance.

 

Mike=20 Wills

 

 

It is not obvious until you start graphing = the open=20 and close events, but the side port which uses the side of the rotor = as a=20 shutter to open and close the port, offers Mazda great latitude in = port=20 timing.  In the periphery ported engine (both ports) it is = impossible to=20 arrive at zero overlap, and have an engine that will produce any power = at all.=20 The apex seal does not close off either port at all, it just valves = gasses in=20 one direction or another.

 

In addition, the overlap of the periphery = ported=20 engine is far more effective flow wise than overlap in the side ported = engine.=20 One apex seal is above the intake port when the opposing apex seal is = below=20 the exhaust port. Flow between the two is=20 unobstructed.

 

So, at low RPM you get fresh mixture leaving = through=20 the exhaust port, and combinations of burned and unburned fuel and = exhaust=20 gasses flowing partway back into the intake=20 runners.

 

This reduces the low RPM output to the point = that the=20 engine seems quit docile, and is easy to drive around in the car, = slowly, or=20 possibly taxi in an aircraft.  This would make off idle tuning = data=20 useless as there will be fuel burning right on top of the EGT probes, = and=20 unburned fuel reaching the F/A sensor. =20

 

The engine will act along the lines of = a piston=20 engine with a long duration cam. When the engine reaches its happy RPM = where=20 all of the mixture is burning inside the engine, it will step up on = the=20 "CAM" and you will see what a good = idea this=20 was. Use slow throttle inputs until you find the "WOW" RPM, and be = ready with=20 all available rudder.

 

When we first ran a factory periphery port = engine, we=20 found that there were places on the track that would not allow full = throttle.=20 This with 11" wide slicks. Thank Heaven for rev limiters. The driver = reported=20 the rear end getting real loose cresting hills and=20 bumps.

 

Why yes it=20 was..........

 

Lynn E.=20 = Hanover 

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