Return-Path: Received: from bree.pipcom.com ([204.92.62.3] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with SMTP id 2585543 for flyrotary@lancaironline.net; Fri, 19 Sep 2003 08:17:29 -0400 Received: (qmail 5848 invoked from network); 19 Sep 2003 12:17:21 -0000 Received: from ras3-23.pipcom.com (HELO new) (204.92.62.155) by bree.pipcom.com with SMTP; 19 Sep 2003 12:17:21 -0000 Message-ID: <003101c37ea7$9756eb40$0b3cfea9@new> From: "Peter Cowan/Lexy Cameron" To: "Rotary motors in aircraft" , "Jon Lauter RPMC" References: Subject: Re: [FlyRotary] Re: Whats good for Racing is necessarily good for aircraft was Re: Intake questions Date: Fri, 19 Sep 2003 08:13:43 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002E_01C37E85.F0F14640" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_002E_01C37E85.F0F14640 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageThis may be just side commentary and a useless data point, but = for what it's worth here is another somewhat different comparison. Also = I've copied Jon Lauter on this because he must have some more = knowledgeable input. I have one of Jon's Rotary Power Marine engines in = a boat. (Cut that laughter right now). He rated it at 175hp and has a = short manifold to a carb just above it on the intake side of the engine = (also distributer ignition, turbo block and rotors).=20 My "dyno" comparison is with the previous engine a 150hp johnson = outboard (Will you guys cut that out?) The current installation must be = well over 100lbs heavier due to the conversion from an outboard to a = stern drive but turning only 4500 I'm the same speed as the 150 hp so I = feel pretty comfortable that should I let this get up to 6500 I'd have = that 175. Pretty scientific, I know. Hopefully Jon will respond. By the way, it is really nice cooling a boat engine! Peter Greetings, I'm probably about to prove that I haven't paid any attention to = any of the intake construction threads, but here goes... I know there's = special length that will tune the intake to make more power. Ed knows = what this is, but if he tells us, he has to kill us (a slow painful = death, involving 60 slides) :-) =20 power band, so I started wondering if I could "tune" it with = individual pipes on the inlet side of the TB. =20 Thanks, Rusty (Scotty, I need more power!)=20 Hi, Rusty.....I purchased the short intake manifold from Dave = Atkins. He claims he has more than adequate power with his, and that = idle is also good. Look at all the race cars and racing motorcycles = that have the carbs or throttle bodies right next to the engine. They = seem to generate a lot of power that way. For what it's worth. Paul Conner Paul is correct. There are any number of intake configurations = that will produce adequate power for the RV-6. I am told that Dave = Atkin's intake permits him to generate approx 160HP which is certainly = adequate for an RV and could even provide thrilling performance in a low = weight RV I'll have to say I've flow an RV with adequate (whatever that = means) performance while producing as little as 120HP. The cruise was = around 180 TAS which was adequate because even today I generally elected = to cruise at 170 TAS to conserve fuel, but take off and climb with 120 = HP in my somewhat heavy bird were agony! Paul, not disputing what you say at all, but you have to = consider the different application. you are making the same assumption = that I made with my first intake. Yes, I listened to the Racing guys = and I'm certain that their advice was just peachy for racing - if you = are turning over 7000-8000 rpm. Than rpm range means short runners and = large diameter inlets are the cats meaow. =20 But, I can tell you from personal experience that if you think = you are going to put a curise prop on your RV-6 with that set up and = think you are going to turn 7000-8000 rpm with a 2.17:1 PSRU you are = going to be sadly disappointed. Tracy Crook turns as high an RPM with = that set up as anyone I know (has hit 214 mph TAS) and maxs out at = around 6400 rpm. His tubes are 1.25 and 1.5" in diameter as best I = recall and wrap over the top of his engine so that is air intake sits on = the top middle of his cowl. So the tubes are not short. =20 The auto and motor cycle guys have one advantage - they have = gear boxes which permit them to wind the engine up into those higher rpm = ranges with a lighter load (lower gear) before shifting to the next = ratio (where you do indeed generate more power), but we can't wind our = engine and then shift gears (at least not yet). Bill Eslick initially use a very short induction system which = provided very disappointing performance results. His report (earlier on = the list this week) indicates that once he went with a different (read - = longer intake, copied after Tracy's as was mine) his performance = improved so that he now keeps up with the 160 HP Lycoming powered RV-6s. = You have to select the induction system parameters that is = realistic for your application! What sucks for us - works for the race = guys, what works for us -would suck for the race guys. Its like apples = and oranges (so to speak) {:>) Now, I will be the first to say, if you want to experiment or if = you find for cost, configuration or convience reasons you want to try = some particular intake configuration, please do so. I've been wrong = before and I am certain will be in the future - but, do it with your = eyes open and understanding of what performance might reasonably be = expected. Best Regards Ed Anderon Hi, Ed.....thanks for the post and education. I guess I was = kinda thinking that if Dave Atkins's RV performs that well with his = short intake manifold, my aerodynamically cleaner canard should perform = equally to, or hopefully better? The primary reason I liked his intake = was because it is truly "bolt on" and go. I tried to buy the wrap-over = manifold from Powersport, but their reply was...."sorry, we can't help = you". I'm sure that experimenters such as yourself, who know and = understand intake systems better than I, can tweak more power out of = these engines. The latest effort I am going to attempt is a wrap-over = system similar to Paul Lamar's, but with only two intake runners. The = intake manifold I ordered is cast so that the four intakes go into two = almost immediately, and from there I will make my aluminum tubing wrap = over the top of the engine (as close as possible for cowling clearance) = and then terminate with my TWM throttlebody with the built-in injectors. = )(Also purchased from Dave Atkins, because it was another "bolt on"). = Did I mention that I like bolt-ons? I truly appreciate the time and = effort you invest into improving these rotary installations for = aircraft. Thanks again. Paul Conner ------=_NextPart_000_002E_01C37E85.F0F14640 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
This may be just side commentary and a = useless data=20 point, but for what it's worth here is another somewhat different=20 comparison. Also I've copied Jon Lauter on this because he must have = some more=20 knowledgeable input. I have one of Jon's Rotary Power Marine =  engines in a=20 boat. (Cut that laughter right now). He rated it at 175hp and has a = short=20 manifold to a carb just above it on the intake side of the engine (also=20 distributer ignition, turbo block and rotors).
My "dyno" comparison is with the = previous engine a=20 150hp johnson outboard (Will you guys cut that out?)  The current=20 installation must be well over 100lbs heavier due to the conversion from = an=20 outboard to a stern drive but turning only 4500 I'm the same speed as = the 150 hp=20 so I feel pretty comfortable that should I let this get up to 6500 I'd = have that=20 175. Pretty scientific, I know.
Hopefully Jon will = respond.
By the way, it is really nice cooling a = boat=20 engine!
Peter
Greetings,
 
I'm = probably about=20 to prove that I haven't paid any attention to any of the intake=20 construction threads, but here goes...  I know there's = special=20 length that will tune the intake to make more power.  Ed = knows what=20 this is, but if he tells us, he has to kill us (a slow painful = death,=20 involving 60 slides)  :-) 
 power band, so I started wondering if = I could=20 "tune" it with individual pipes on the inlet side of the=20 TB.  
 
Thanks,
Rusty = (Scotty, I=20 need more power!) 
 
Hi, = Rusty.....I=20 purchased the short intake manifold from Dave Atkins. He claims = he has=20 more than adequate power with his, and that idle is also = good. =20 Look at all the race cars and racing motorcycles that have the = carbs or=20 throttle bodies right next to the engine.  They seem to = generate a=20 lot of power that way. For what it's worth.
 
 Paul=20 Conner
 
 
 
Paul is = correct.=20 There are any number of intake configurations that will produce = adequate=20 power for the RV-6. I am told that Dave Atkin's intake = permits him=20 to generate approx 160HP which is certainly adequate for an RV = and could=20 even provide thrilling performance in a low weight=20 RV
 
I'll = have to=20 say I've flow an RV with adequate (whatever that = means)=20 performance while producing as little as 120HP.  The = cruise=20 was around 180 TAS which was adequate because even today I=20 generally elected to cruise at 170 TAS to conserve fuel, but = take off=20 and climb with 120 HP in my somewhat heavy bird were=20 agony!
 
 Paul, not=20 disputing what you say at all, but you have to consider the = different=20 application.  you are making the same assumption that =  I=20 made with my first intake.  Yes, I listened to the Racing = guys and=20 I'm certain that their advice was just peachy for racing - if = you are=20 turning over 7000-8000 rpm.  Than rpm range means short = runners and=20 large diameter inlets are the cats meaow.  =
 
But, I = can tell you=20 from personal experience that if you think you are going to put = a curise=20 prop on your RV-6 with that set up and think you are going to = turn=20 7000-8000 rpm with a 2.17:1 PSRU you are going to be sadly=20 disappointed. Tracy Crook turns as high an RPM with that = set up as=20 anyone I know (has hit 214 mph TAS) and maxs out at around 6400=20 rpm.  His tubes are 1.25 and 1.5" in diameter as best I = recall and=20 wrap over the top of his engine so that is air intake sits on = the top=20 middle of his cowl.  So the tubes are not=20 short.  
 
 The auto and=20 motor cycle guys have one advantage - they have gear boxes which = permit=20 them to wind the engine up into those higher rpm ranges with a = lighter=20 load (lower gear) before shifting to the next ratio (where you = do indeed=20 generate more power), but we can't wind our engine and then = shift gears=20 (at least not yet).
 
Bill = Eslick=20 initially use a very short induction system which provided very=20 disappointing performance results.  His report = (earlier on the=20 list this week) indicates that once he went with a = different (read=20 - longer intake, copied after Tracy's as was mine) his = performance=20 improved so that he now keeps up with the 160 HP Lycoming = powered=20 RV-6s.
 
You = have to select=20 the induction system parameters that is realistic for your=20 application!  What sucks for us - works for the race guys, = what=20 works for us -would suck for the race guys.  Its like = apples and=20 oranges (so to speak) {:>)
 
Now, I = will be the=20 first to say, if you want to experiment or if you find for cost, = configuration or convience reasons you want to try some = particular=20 intake configuration, please do so.  I've been wrong before = and I=20 am certain will be in the future - but, do it with your eyes = open and=20 understanding of what performance might reasonably be=20 expected.
 
Best=20 Regards
 
Ed=20 Anderon
 
 
 
Hi, = Ed.....thanks=20 for the post and education. I guess I was kinda thinking that if = Dave=20 Atkins's RV performs that well with his short intake manifold, = my=20 aerodynamically cleaner canard should perform equally to, or = hopefully=20 better?  The primary reason I liked his intake was because = it is=20 truly "bolt on" and go.  I tried to buy the wrap-over = manifold from=20 Powersport, but their reply was...."sorry, we can't help = you".  I'm=20 sure that experimenters such as yourself, who know and = understand intake=20 systems better than I, can tweak more power out of these = engines. =20 The latest effort I am going to attempt is a wrap-over system = similar to=20 Paul Lamar's, but with only two intake runners. The intake = manifold I=20 ordered is cast so that the four intakes go into two almost = immediately,=20 and from there I will make my aluminum tubing wrap over the top = of the=20 engine (as close as possible for cowling clearance) and then = terminate=20 with my TWM throttlebody with the built-in injectors. )(Also = purchased=20 from Dave Atkins, because it was another "bolt on").   = Did I=20 mention that I like bolt-ons?  I truly appreciate the time = and=20 effort you invest into improving these rotary installations for=20 aircraft.  Thanks again.  Paul = Conner
 
 
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