X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-mealy.atl.sa.earthlink.net ([209.86.89.69] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2197113 for flyrotary@lancaironline.net; Tue, 24 Jul 2007 18:39:48 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.69; envelope-from=jerryhey@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=WNmICsldy/qF57E2R6KL+sGimFlTkCaiX1TqlPydzHFrt1JQdnNrWRApe5X2tZQ1; h=Received:Mime-Version:In-Reply-To:References:Content-Type:Message-Id:From:Subject:Date:To:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [71.49.145.6] (helo=[192.168.0.101]) by elasmtp-mealy.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1IDT26-0004pC-E2 for flyrotary@lancaironline.net; Tue, 24 Jul 2007 18:39:11 -0400 Mime-Version: 1.0 (Apple Message framework v752.3) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-23-851131556 Message-Id: <1FE86A72-EFF6-40AA-BC41-B3E9FA0EE16D@earthlink.net> From: Jerry Hey Subject: Re: [FlyRotary] Re: carbs vs efi Date: Tue, 24 Jul 2007 18:39:21 -0400 To: "Rotary motors in aircraft" X-Mailer: Apple Mail (2.752.3) X-ELNK-Trace: 8104856d7830ec6b1aa676d7e74259b7b3291a7d08dfec795b165f69bef58a9e67c3bcce736e1bed350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 71.49.145.6 --Apple-Mail-23-851131556 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed George, those hp claims seem wildly exaggerated to me. I have never heard anyone claim 200 hp for a two rotor street port at 7500 rpm. But I hope they do turn out to be true. I accept the Power Sport numbers of around 107.5 hp per rotor with a 1.5 i.d. p port. Perhaps if they had turned 7500 rpm they might have made somewhat more hp. According to calculations done for my original p port, a 1.5 i.d.port will flow 8000 rpm just fine. Side ports are relatively terrible when compared to a p port. I don't think their comparable size has relevance. Jerry On Jul 24, 2007, at 6:10 PM, George Lendich wrote: > Jerry, > Sounds good! > The Street port single will give about 116hp at 7,500, but you need > 1.18 x2 sq" minimum ( 2.36 sq") = 44 Dia inlet. > > David McCandles has found some old info, which I will forward under > separate cover, which confirms these numbers although I haven't > read it through myself as yet. > > The RX8 uses smaller runners but more of them, the inlet area is > massive in total, the smaller runner maintains the velocity. > However because the Rotary doesn't suck like a piston engine > ( sucking creates velocity) the advantages of velocity over area > needed, are limited. > > The 12A and 13B are the same size P-port 43mm, the timing/position > are the same. > We have to start to accept that they know the advantages of sizing > and position. > George > George,? I just got back from Oshkosh which would have been a > wasted trip except that I got to fly a CH 701 amphib off the > water.? This was a first for ?yours truly. ? ?What a lot of fun.? > The airplane handles perfectly and is the right one for me. ? ?It > is limited by the designer to 100 hp and 200 lbs for the engine > installation. So I am in the in enviable situation of not wanting > to get too much out of my p port. The plane was powered by a 100 hp > Rotax.? ?It did very well.? ? > > Re your analysis comparing side ports with p ports, I wonder if > such an analysis is even possible as they are quite different.? > Anyway, I doubt that a standard port can deliver 100 hp or a street > port 130 hp. per rotor, certainly not when limited to 7500 rpm.? Of > course I am only guessing.? No real knowledge or experience.?? > > The only carb I saw at Oshkosh was the aero carb.? It is sized by > HP and they recommend the 38mm for? 125 to 160 hp.? This is too > large for my purposes.? I am considering going down to 35mm? (90 to > 125 hp) ? ?The problem is that I already have 38mm p ports.? Also, > of interest is that they do not recommend ram air. That simplifies > the plumbing and the cowl. ? ?The demo engine had rather long, > small dia runners and an air filter attached to the carb.? That is > the "system." ((on an 80 hp v.w.))? ?If I can get the drive figured > out, ?I will build it with RB's aluminum side plates and Atkins > eccentric. ?BTW the 701 is a high wing. ?The system will be > strictly gravity. ? ?? ?Jerry > > > <003501c7ce3f$7b719010$c66b1fd3> > > <003601c7ce3f$7b719010$c66b1fd3> > > On Jul 21, 2007, at 10:14 PM, George Lendich wrote: > >> Jerry, >> I'm trying to compare the carb inlet area to port or P-port areas. >> Standard Port area 32 deg ATDC to 50 degree ABDC = 1.18 sq " each >> side (x2 = 2.36sq")- using the front and back housings only. >> ? >> A street port will be 1.5sq" x 2 = 3sq" >> . >> A 44mm P-port = 2.35sq" >> A?42mm p-port = 2.14sq" >> A 40mm P-port = 1.94sq" >> A 38mm P-port = 1.75sq" >> So you see a side port on a single has more port area than a small >> P-port. >> Perhaps the velocity will make up for less area. >> The street port is bigger again at 3 sq" - this equates to 50mm port. >> ? >> The standard port gives about 100 hp, the street port about 130hp >> each rotor. >> I wouldn't want to choke down the port areas with too? restrictive >> inlet carby?area. I can't see how a 38mm will cut the mustard when >> your own calculations suggest 1.6 P-port = 42mm sq". >> ? >> In reality I'm only looking for 130HPat most, if I can get that. >> ? >> I can run a 41mm ID SS tube p-port with a 42mm Carby ( and hope >> velocity makes up the difference) Or I can run with two 1.5 street >> ported side ports 3 sq" with two smaller carbs, perhaps 2x32mm. >> ? >> BTW street ported 13B has been dynoed to 264hp can't remember the >> RPM - it might have been higher than what we run. >> More confused than ever! >> ? >> Does anyone know the IO/IC and size and HP?of the factory P-port. >> ? >> Lynn, does the timing given, calculated by the rotor uncovering >> and covering the port, or the side seal uncovering/covering the >> port opening? >> I was thinking the RX8 rotor will be slightly different (bigger) >> with the harased edges. >> George ( down under) >> ? >> ? >> ? >> ? >> ----- Original Message ----- >> From: Jerry Hey >> To: Rotary motors in aircraft >> Sent: Sunday, July 22, 2007 9:17 AM >> Subject: [FlyRotary] Re: carbs vs efi >> >> George,? maybe I have the wrong idea, but I don't understand why >> you need such a large bore carb for the single rotor.? No way you >> are going to produce more than 150 hp.? I think 38mm would be >> enough.? This is what Aero Carb recommends for the 0-320.? Jerry >> >> >> On Jul 21, 2007, at 5:56 PM, George Lendich wrote: >> >>> Jerry, >>> Looks like Pat was wrong about Revmaster having a 44mm, the >>> biggest they go to is 42mm ( at the present time)?and that costs >>> $380. If I remember the 32mm costs $320. >>> Jerry I would be interested in feed back on what you thought >>> about the Aero Carb, especially how it's constructed - their all >>> a little different. >>> I do like the Ellison but it's too bloody expensive. >>> George ( down under) >>> George,? the web site says $326.00.? You might want to compare >>> the aero carb which is similar.??http://www.aeroconversions.com >>> I will be looking at both at Oshkosh on Tuesday and Wednesday >>> next week.? Jerry >>> >>> >>> Jerry >>> >> >>> >>> >>> >>> >>> >>> On Jul 20, 2007, at 10:06 PM, George Lendich wrote: >>> >>>> ? >>>> I have been surprised at the recent flurry of carb postings.? I >>>> assumed that everyone was doing EFI.? having experienced total >>>> electrical failure in march on a trip to the Bahamas I was >>>> thinking a lot about that Neanderthal carb bolted under my O320 >>>> and the magnetos, all unaware of what was going on in the radio, >>>> GPS,?and nav lights departments.??? the reality is that you >>>> don't want a reserve battery to get you to the ground safely, >>>> you want to get to the Bahamas and back and THEN look into >>>> what's wrong. >>>> my questions are "how much power/performance is lost with a >>>> carb, and which carbs can do manual mixture?".? is it stupid to >>>> ask if the Lycoming carb could run a 13B?? someone mentioned >>>> Harley carbs?having a?good history of rough service.? what about >>>> marvel/schebler?? is this question heresy? :-)? isn't efi a bit >>>> of overkill for an engine that basically runs at 100% power, 75% >>>> power and idle?? scanning thru the archives I see a lot of >>>> postings regarding mixture, mapping, abrupt failures and such.? >>>> does this complexity buy us 5%, 20%?? the question of turbo- >>>> charging seems to?beg similar line of questioning.??? kevin >>>> ? >>>> Kevin, >>>> It's probably my fault, with a number of chaps helping me out >>>> with information. >>>> My Buddy Bill Jepson will tell you nothing beats EFI and when >>>> it's running well, he's absolutely right! >>>> Not only that it is the best for? fuel efficiency, leaning >>>> reading fuel flow etc. etc. >>>> However I'm developing a single rotor and looking at all sorts >>>> of issues including cost effectiveness of less elaborate >>>> installations. I'm also not keen on high pressure >>>> fuel under the cowl. >>>> Most importantly I'm not?an electronics person and seeing the >>>> problems experienced by others has me more than a little >>>> nervous, in regard to EFI. >>>> Of course I know very little about carbies, so their helping me >>>> with this as well. >>>> The Revmaster might be the choice for me, but I'm awaiting the >>>> sticker shock! >>>> George ( down under) >>>> >>> >>> >> >> > > --Apple-Mail-23-851131556 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 George,=A0 those hp claims seem = wildly=A0exaggerated=A0to me.=A0 I have never heard anyone claim=A0 200 = hp for a two rotor street port at 7500 rpm.=A0 But I hope they do turn = out to be true.=A0 I accept the Power Sport numbers of around 107.5 hp = per rotor with a 1.5 =A0i.d. p port. =A0Perhaps if they had turned 7500 = rpm they might have made somewhat more hp. =A0According to calculations = done for my original p port, a 1.5 i.d.port will flow 8000 rpm just = fine.=A0 =A0Side ports are relatively terrible when compared to a p = port. I don't think their comparable size has relevance.=A0 = Jerry

=A0
On Jul 24, = 2007, at 6:10 PM, George Lendich wrote:

The Street port single will give about 116hp at = 7,500, but you need 1.18=A0 x2=A0sq" minimum ( 2.36 sq") =3D 44 Dia = inlet.
=A0
=A0
=A0
George,? I just got = back from Oshkosh which would have been a wasted trip except that I got = to fly a CH 701 amphib off the water.? This was a first for ?yours = truly. ? ?What a lot of fun.? The airplane handles perfectly and is the = right one for me. ? ?It is limited by the designer to 100 hp and 200 lbs = for the engine installation. So I am in the in enviable situation of not = wanting to get too much out of my p port. The plane was powered by a 100 = hp Rotax.? ?It did very well.? ?

Re your analysis comparing = side ports with p ports, I wonder if such an analysis is even possible = as they are quite different.? Anyway, I doubt that a standard port can = deliver 100 hp or a street port 130 hp. per rotor, certainly not when = limited to 7500 rpm.? Of course I am only guessing.? No real knowledge = or experience.??

The only carb I saw at = Oshkosh was the aero carb.? It is sized by HP and they recommend the = 38mm for? 125 to 160 hp.? This is too large for my purposes.? I am = considering going down to 35mm? (90 to 125 hp) ? ?The problem is that I = already have 38mm p ports.? Also, of interest is that they do not = recommend ram air. That simplifies the plumbing and the cowl. ? ?The = demo engine had rather long, small dia runners and an air filter = attached to the carb.? That is the "system." ((on an 80 hp v.w.))? ?If I = can get the drive figured out, ?I will build it with RB's aluminum side = plates and Atkins eccentric. ?BTW the 701 is a high wing. ?The system = will be strictly gravity. ? ?? ?Jerry


<003501c7ce3f$7= b719010$c66b1fd3>

<003601c7ce3f$7= b719010$c66b1fd3>

On Jul 21, 2007, at 10:14 = PM, George Lendich wrote:

I'm trying to compare the carb inlet area to = port or P-port areas.
Standard Port area 32 deg ATDC to 50 degree = ABDC =3D 1.18 sq " each side (x2 =3D 2.36sq")- using the front = and back housings only.
?
A street port will be 1.5sq" x 2 =3D = 3sq"
.
A 44mm P-port =3D = 2.35sq
A?42mm p-port =3D = 2.14sq"
A 40mm P-port =3D = 1.94sq"
A 38mm P-port =3D = 1.75sq"
So you see a side port on a single has more = port area than a small P-port.
The street port is bigger again at 3 sq" - this = equates to 50mm port.
?
The standard port gives about 100 hp, the street port = about 130hp each rotor.
area. I can't see how a 38mm will cut the mustard = when your own calculations suggest 1.6 P-port =3D 42mm = sq".
?
In reality I'm only looking for 130HPat most, if I = can get that.
?
I can run a 41mm ID SS tube p-port with a 42mm Carby = ( and hope velocity makes up the difference) Or I can run with two 1.5 = street ported side ports 3 sq" with two smaller carbs, perhaps = 2x32mm.
?
BTW street ported 13B has been dynoed to 264hp can't = remember the RPM - it might have been higher than what we = run.
More confused than = ever!
?
Does anyone know the IO/IC and size and HP?of the = factory P-port.
?
Lynn, does the timing given, calculated by the rotor = uncovering and covering the port, or the side seal uncovering/covering = the port opening?
I was thinking the RX8 rotor will be slightly = different (bigger) with the harased = edges.
George ( down = under)
?
?
?
?
----- Original = Message -----
To:

George,? maybe I have the wrong = idea, but I don't understand why you need such a large bore carb for the = single rotor.? No way you are going to produce more than 150 hp.? I = think 38mm would be enough.? This is what Aero Carb recommends for the = 0-320.? Jerry







On Jul 20, = 2007, at 10:06 PM, George Lendich wrote:

?
I have been surprised at the = recent flurry of carb postings.? I assumed that everyone was doing EFI.? = having experienced total electrical failure in march on a trip to the = Bahamas I was thinking a lot about that Neanderthal carb bolted under my = O320 and the magnetos, all unaware of what was going on in the radio, = GPS,?and nav lights departments.??? the reality is that you don't want a = reserve battery to get you to the ground safely, you want to get to the = Bahamas and back and THEN look into what's = wrong.
my questions are "how much power/performance is lost with a = carb, and which carbs can do manual mixture?".? is it stupid to ask if = the Lycoming carb could run a 13B?? someone mentioned Harley = carbs?having a?good history of rough service.? what about = marvel/schebler?? is this question heresy? :-)? isn't efi a bit of = overkill for an engine that basically runs at 100% power, 75% power and = idle?? scanning thru the archives I see a lot of postings regarding = mixture, mapping, abrupt failures and such.? does this complexity buy us = 5%, 20%?? the question of turbo-charging seems to?beg similar line of = questioning.??? kevin
?
Kevin,
It's probably my fault, with a = number of chaps helping me out with = information.
My Buddy Bill Jepson will tell = you nothing beats EFI and when it's running well, he's absolutely = right!
Not only that it is the best for? fuel efficiency, leaning = reading fuel flow etc. = etc.
However I'm developing a single rotor and looking at all = sorts of issues including cost effectiveness of less elaborate = installations. I'm also not keen on high = pressure
fuel under the = cowl.
Most importantly I'm not?an electronics person and seeing the = problems experienced by others has me more than a little nervous, in = regard to EFI.
Of course I know very little = about carbies, so their helping me with this as = well.
The Revmaster might be the choice for me, but I'm awaiting = the sticker shock!
George ( down = under)








= --Apple-Mail-23-851131556--