X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail02.syd.optusnet.com.au ([211.29.132.183] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTPS id 3483161 for flyrotary@lancaironline.net; Sun, 08 Feb 2009 17:47:30 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.183; envelope-from=lendich@optusnet.com.au Received: from ownerf1fc517b8 (d220-236-255-172.dsl.nsw.optusnet.com.au [220.236.255.172]) by mail02.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id n18Mkkfk021517 for ; Mon, 9 Feb 2009 09:46:47 +1100 Message-ID: <6FB34A324DCB48EE8A39868B80648CD4@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Exhaust lengths Date: Mon, 9 Feb 2009 08:46:49 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006E_01C98A92.F25A9210" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 0617-3, 04/28/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_006E_01C98A92.F25A9210 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Richard, Another alternative to the SS inlet tube welded to the steel housing = liner, is welding an Al tube to the Al housing - inside the water = jacket. It's being done locally for racing and lasts longer than the = glued in place tube. In fact they haven't had any trouble with any = leaking ( leaking coolant into combustion chamber) at all. George (down under) ----- Original Message -----=20 From: Richard Sohn=20 To: Rotary motors in aircraft=20 Sent: Monday, February 09, 2009 4:38 AM Subject: [FlyRotary] Re: Exhaust lengths If someone wants to do a Renesis P-Port I would be glad to do the = rotor housings. I just finished the two rotor housings for my first = flyable engines. The port insert is as it is in the engine I have been = running up to now. I know it works.=20 Mark Steitle's welding might work, but I am not aware of any engine = running with it so far. Richard Sohn N2071U ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Sunday, February 08, 2009 11:40 AM Subject: [FlyRotary] Re: Exhaust lengths FWIW, the people at Racing Beat said that the Renesis is a very = different animal than peripherial exhaust port rotaries when it comes to = exhaust systems. As I recall, they said they got only about an 8 HP = improvement when going from stock (RX-8) exhaust system with cats & the = works, to a full race setup with headers, race mufflers, etc. That is = TINY in comparison to the earlier engines.=20 In other words, the Renesis is very non-critical when it comes to = exhaust systems. Just keep the back pressure down and you'll do pretty = well. At least that was my conclusion. Note there is zero overlap in = intake / exhaust cycles in the Renesis. BTW I'm still waiting for someone to build & test a peripheral = intake port Renesis. I think that would be a great setup for aircraft = applications. =20 Tracy On Sun, Feb 8, 2009 at 12:13 PM, The Mallorys = wrote: Lynn, Thanks for the info. So it looks like the total length after the = collector doesn't really matter. I'm using the stock Renesis tubing up = to the 180* bend, so I'm assuming(maybe incorrectly) that they have done = the math and have the lengths right. Chris From: Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Sunday, February 08, 2009 9:47 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Exhaust lengths Lynn,=20 Thanks for the excellent response. So, there is sort of a dynamic = tuning effect going on as happens in the 2-rotor intake. Appreciate = your sharing your knowledge with the group. Mark S. On Sun, Feb 8, 2009 at 8:10 AM, Lynn Hanover = wrote: Lynn,=20 I have a question regarding exhaust/inlet lengths that I've wanted = to ask for quite a while. =20 Q: Do the optimum lengths of 12/24/36/102 hold true only for the = 2-rotor engines or does it work for the 3-rotor engines too?=20 Mark S.=20 The object of the headers, is that the supersonic pulses need to = be neatly laid into the collector one after the other in exactly the = same spacing. This makes for a good sounding engine, even after = muffling. It also makes for great scavenging, and if the muffler is not = too restrictive, can maintain a low pressure in the exhaust system. That = becomes free HP. For example: I use GE silicone tub and tile caulk on = the exhaust header flange. No gasket. It need not be high temp anything = because it just is never very hot being clamped to the rotor housing. = There is no pressure at all to deal with in this junction, as the = supersonic flow is well below sea level pressure (One Barr). If it did = ever leak it would draw in local air into the header pipe, and make = cracking sounds on closed throttle. If it leaks at all, it will leak at = idle because velocity is nearing zero. =20 The lengths are from collections of street headers designed to = help street engine build up the rotaries dismal low speed torque. The = longer the header pipes the more solid the slugs from each firing event, = and the better the scavenging and low end torque.=20 Once you have a 11" of header, you have two full pulses from each = housing and if you collect them with the exact same length of pipe you = have done as much as you need for anything over 3,000 RPM. As the revs = go higher, the headers (In effect) become longer because more full = pulses will fit in each pipe. And here is the important part. The pipes need to be exactly the same length to the collector. The = collector needs to be uniform and silk smooth inside. At 6,000 RPM you = are blending 12,000 pulses together, or 18,000 pulses from a three = rotor, just like cards being shuffled. If you get any two pulses = impinging on each other there will be far less than the very best = performance available. Plus the engine will be annoying. Too loud but = sounds great entering the pattern is way better than nobody talks to = you, and Jimmy's dog won't come out from under the truck. I had a length of corrigated plastic hose looking stuff, used to = cover bundles of wire in trucks. It just fit inside of 1 7/8" ID tubing. = I had bends made up and with my abrasive saw I would fit together the = headers, tacking on pieces and fitting them into the spaces as I went = along. I smoothed the joints inside just as though each piece would be a = finished piece. Once at the collector. (both pipes parallel for 3 = inches) I would shove the plastic hose up each pipe to the flat plate = gasket over each exhaust port. Add masking tape to the hose at the end = of the front header, then pull it out and shove in the rear header, to = see where the tape ended up. It is easy to lengthen and shorten the = straight runs out of the flange to correct small differences in length.=20 I am not trying to tune the engine with header length. Just trying = to get the exhaust out without screwing away any HP that a poorly = designed system will do. The 4 cylinder engines seem to favor a 32-34 = inch header to fluff up the torque that a big cam will take away. So if = you need help in a 4 cylinder from 3,000 to 4,500 there is your header = length. I used 24" because the engine builder uses that on the dyno. It = is typical to have two nodes where any paticular header length will add = a bit of power. The lower of the two is seldom high enough to use for = anything but a street engine.=20 Just as in piston engines, long, shallow angle collectors produce = better torque over a wide RPM range. Short, steeply angled collectors = produce better torque over a short range of RPM. =20 The two rotor is two one rotor engines on the same crankshaft. The = three rotor is three one rotor engines on the same crank shaft. The best = outcome is to have both, or all three perform at about the same rate as = the others. You will notice that there seem to be complaints as to EGT, = water temps, compression, vibration fuel flow, exhaust color, and so on = with every recoverable piece of data. The front housing gets the coldest = coolant on one side and the hottest coolant on the other side. The = three rotor (I suspect) may have even greater differences). So in those = areas where you can get the same outcome, you should try to get the same = outcome. As in the intake and header lengths. There you go.......... 15 free HP. Lynn E. Hanover =20 -------------------------------------------------------------------------= --- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.0.233 / Virus Database: 270.10.19/1939 - Release Date: = 02/07/09 13:39:00 -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_006E_01C98A92.F25A9210 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Richard,
Another alternative to the SS = inlet tube=20 welded to the steel housing liner, is welding an Al tube to the Al = housing -=20 inside the water jacket. It's being done locally for racing and lasts = longer=20 than the glued in place tube. In fact they haven't had any trouble with = any=20 leaking ( leaking coolant into combustion chamber) at all.
George (down under)
----- Original Message -----
From:=20 Richard=20 Sohn
Sent: Monday, February 09, 2009 = 4:38=20 AM
Subject: [FlyRotary] Re: = Exhaust=20 lengths

If someone wants to do a Renesis = P-Port I would=20 be glad to do the rotor housings. I just finished the two rotor = housings for=20 my first flyable engines. The port insert is as it is in the engine I = have=20 been running up to now. I know it works.
Mark Steitle's welding might work, = but I am not=20 aware of any engine running with it so far.
 
Richard Sohn
N2071U
 
----- Original Message -----
From:=20 Tracy Crook
To: Rotary motors in = aircraft=20
Sent: Sunday, February 08, = 2009 11:40=20 AM
Subject: [FlyRotary] Re: = Exhaust=20 lengths

FWIW, the people at Racing Beat said that the Renesis = is a=20 very different animal than peripherial exhaust port rotaries when it = comes=20 to exhaust systems.  As I recall, they said they got only about = an 8 HP=20 improvement when going from stock (RX-8) exhaust system with cats = & the=20 works, to a full race setup with headers, race mufflers, etc.  = That is=20 TINY in comparison to the earlier engines.

 In other = words, the=20 Renesis is very non-critical when it comes to exhaust systems.  = Just=20 keep the back pressure down and you'll do pretty well.  At = least that=20 was my conclusion.  Note there is zero overlap in intake / = exhaust=20 cycles in the Renesis.

BTW I'm still waiting for someone to = build=20 & test a peripheral intake port Renesis.  I think that = would be a=20 great setup for aircraft applications. 

Tracy

On Sun, Feb 8, 2009 at 12:13 PM, The = Mallorys <candtmallory@cebridge.net&g= t;=20 wrote:

Lynn,

Thanks = for the=20 info.  So it looks like the total length after the collector = doesn't=20 really matter.  I'm using the stock Renesis tubing up to the = 180*=20 bend, so I'm assuming(maybe incorrectly) that they have done the = math and=20 have the lengths right.

 

Chris

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of = Mark=20 Steitle
Sent: Sunday, February 08, 2009 9:47 = AM
To:=20 Rotary motors in aircraft
Subject: [FlyRotary] Re: = Exhaust=20 lengths

 

Lynn,

Thanks for the = excellent=20 response.  So, there is sort of a dynamic tuning effect going = on as=20 happens in the 2-rotor intake.  Appreciate your sharing your=20 knowledge with the group.

Mark S.

On Sun, Feb 8, 2009 at 8:10 AM, Lynn Hanover <lehanover@gmail.com> wrote:

Lynn,

I have a question regarding exhaust/inlet lengths = that=20 I've wanted to ask for quite a while. 

Q:  Do = the=20 optimum lengths of 12/24/36/102 hold true only for the 2-rotor = engines or=20 does it work for the 3-rotor engines too?

Mark = S. 

 

The object of the headers, is that the supersonic pulses need = to be=20 neatly laid into the collector one after the other in exactly the = same=20 spacing. This makes for a good sounding engine, even after = muffling. It=20 also makes for great scavenging, and if the muffler is not too=20 restrictive, can maintain a low pressure in the exhaust system. = That=20 becomes free HP. For example: I use GE silicone tub and tile caulk = on the=20 exhaust header flange. No gasket. It need not be high temp = anything=20 because it just is never very hot being clamped to the rotor = housing.=20 There is no pressure at all to deal with in this junction, as the=20 supersonic flow is well below sea level pressure (One Barr). If it = did=20 ever leak it would draw in local air into the header pipe, and = make=20 cracking sounds on closed throttle. If it leaks at all, it will = leak at=20 idle because velocity is nearing zero.  

 

The lengths are from collections of street headers designed to = help=20 street engine build up the rotaries dismal low speed torque. The = longer=20 the header pipes the more solid the slugs from each firing event, = and the=20 better the scavenging and low end torque. 

 

Once you have a 11" of header, you have two full pulses = from each=20 housing and if you collect them with the exact same length of pipe = you=20 have done as much as you need for anything over 3,000 RPM. As the = revs go=20 higher, the headers (In effect) become longer because more = full=20 pulses will fit in each pipe. And here is the important=20 part.

 

The pipes need to be exactly the same length to the collector. = The=20 collector needs to be uniform and silk smooth inside. At 6,000 RPM = you are=20 blending 12,000 pulses together, or 18,000 pulses from a three = rotor, just=20 like cards being shuffled. If you get any two pulses impinging on = each=20 other there will be far less than the very best performance=20 available. Plus the engine will be annoying. Too loud but sounds = great=20 entering the pattern is way better than nobody talks to you, and = Jimmy's=20 dog won't come out from under the truck.

 

I had a length of corrigated plastic hose looking stuff, used = to cover=20 bundles of wire in trucks. It just fit inside of 1 7/8" ID = tubing. I=20 had bends made up and with my abrasive saw I would fit together = the=20 headers, tacking on pieces and fitting them into the spaces as I = went=20 along. I smoothed the joints inside just as though each piece = would be a=20 finished piece. Once at the collector. (both pipes parallel for 3 = inches)=20 I would shove the plastic hose up each pipe to the flat plate = gasket over=20 each exhaust port. Add masking tape to the hose at the end of the = front=20 header, then pull it out and shove in the rear header, to see = where the=20 tape ended up. It is easy to lengthen and shorten the straight = runs out of=20 the flange to correct small differences in length. 

 

I am not trying to tune the engine with header length. Just = trying to=20 get the exhaust out without screwing away any HP that a poorly = designed=20 system will do. The 4 cylinder engines seem to favor a 32-34 inch = header=20 to fluff up the torque that a big cam will take away. So if you = need help=20 in a 4 cylinder from 3,000 to 4,500 there is your header length. I = used=20 24" because the engine builder uses that on the dyno. It is = typical to=20 have two nodes where any paticular header length will add a bit of = power.=20 The lower of the two is seldom high enough to use for anything but = a=20 street engine.

 

Just as in piston engines, long, shallow angle collectors = produce=20 better torque over a wide RPM range. Short, steeply angled = collectors=20 produce better torque over a short range of = RPM.  

 

The two rotor is two one rotor engines on the same crankshaft. = The=20 three rotor is three one rotor engines on the same crank shaft. = The best=20 outcome is to have both, or all three perform at about the same = rate as=20 the others. You will notice that there seem to be complaints as to = EGT,=20 water temps, compression, vibration fuel flow, exhaust color, and = so on=20 with every recoverable piece of data. The front housing gets the = coldest=20 coolant on one side and the hottest coolant on the other side. =  The=20 three rotor (I suspect) may have even greater differences). So in = those=20 areas where you can get the same outcome, you should try to get = the same=20 outcome. As in the intake and header lengths. There you=20 go..........

 

15 free HP.

 

Lynn E. Hanover  

 



No virus found in this incoming message.
Checked by = AVG -=20 www.avg.com
Version: 8.0.233 / Virus Database: 270.10.19/1939 - = Release=20 Date: 02/07/09 13:39:00

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