X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from lrcmmta07-srv.windstream.net ([166.102.165.79] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4180752 for flyrotary@lancaironline.net; Sat, 27 Mar 2010 09:07:03 -0400 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.79; envelope-from=jskmberki@windstream.net Return-Path: X-WS-COS: WSOB804 X-Cloudmark-Category: Undefined:Undefined X-Cloudmark-Analysis: v=1.1 cv=dtSEbXLG/1AoHohs6V2Li9FP2VIp2uioTqkngh6Nge4= c=1 sm=0 a=3oc9M9_CAAAA:8 a=Hl1Gy0H5AAAA:8 a=RvGrZHpOAAAA:8 a=lkzbJW4e1VycbOQ_XQoA:9 a=mY5rUWbeQ8XjCpLG1PMA:7 a=3Tw7frQ7J0H16VMYnCy3zXKWI9YA:4 a=QEXdDO2ut3YA:10 a=w-bkEBAFUowA:10 a=U8Ie8EnqySEA:10 a=4qoFMyBD9y074P4A:21 a=pE7oW82AHN_wk4Lm:21 a=Ia-xEzejAAAA:8 a=ScgFzrk6C2PPFOFMNBYA:9 a=afxtoz0vd58FyQT9aB8A:7 a=rKD5RS0y-_wvPTELvyKF3im8ZNUA:4 a=EzXvWhQp4_cA:10 a=C9Ex9xq7Qd1xmVIRx4ROgA==:117 X-Cloudmark-Score: 0 Authentication-Results: lrcmmta07 smtp.user=jskmberki; auth=pass (LOGIN) Received: from [174.130.41.235] ([174.130.41.235:60983] helo=joehomepc) by lrcmmta07 (envelope-from ) (ecelerity 2.2.2.45 r()) with ESMTPA id 52/C0-25663-2D20EAB4; Sat, 27 Mar 2010 08:06:27 -0500 Message-ID: <004a01cacdb7$f0b8c2b0$01fea8c0@joehomepc> From: "josrph berki" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: P-Port performance Date: Sat, 27 Mar 2010 09:15:22 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0047_01CACD8E.0737ADA0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1983 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1983 This is a multi-part message in MIME format. ------=_NextPart_000_0047_01CACD8E.0737ADA0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable The nice thing about a 2" runner dia P Port is that if doesn't make = power at the desired rpm you could place a linner in the runners to = reduce the dia. A liitle harder to increase the runner dia without = disassembly. Thisof course depends on how many bends are in the = runners. Joe Berki ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Saturday, March 27, 2010 1:40 AM Subject: [FlyRotary] Re: P-Port performance In a message dated 3/26/2010 8:58:41 PM Eastern Standard Time, = lendich@aanet.com.au writes: =E2=80=9Cthat things that work in one application (like Rx-7 racing) = just great - may well suck in another application.=E2=80=9D =20 Or not suck enough=E2=80=A6. ;) =20 Neilk Here is some more stuff to read, since none of you are building right = now.=20 http://mototuneusa.com/think_fast_intake_porting.htm This fellow fills in some cross section on the intake runners of big = engine street and road race bikes. Even the factory people fall in love with maximum HP numbers to sell = bikes. The big numbers at the top RPM require big intake runners. Big = intake runners means high flow velocity will be at astoundingly high = RPM. This means the reverse will be available at mid and lower RPM. So, = the rider is beaten silly on the road course by some weekend nitwit with = a smaller engine, that appears to be stock. He obviously has less = maximum HP, but seems to be doing quite well with his setup.=20 Because....... The smaller engine has good torque and HP at lower and mid range RPM. = Maybe he is not as fast at the end of the long straightaway, but he = seems to get to his top speed much sooner than the new bike with the = bigger engine. And in road racing and drag racing, it is the first = person to his top speed that wins, not always the highest top speed.=20 Think gear ratio spreads, and area under the curve when you graph HP.=20 Racing engines and airplane engines are the same engines. Some racing = organizations even use rev limiters to equalize competition between car = brands to keep the racing interesting. So you have to imagine that your = club, be it hair club for men or the home built airplane club has a rule = about top RPM.=20 Of course the club has no such rule, but Mother nature does have such = a rule. It has to do with the tip speed of propellers. So once you = calculate the ratio of your reduction unit, you know how fast you can = turn up your engine. And it isn't very much RPM.=20 So now you are unhappy with the torque of the car engine that had good = torque at 2,500 RPM in the street car, and now you want the best torque = to be where? 5,000 RPM with best HP at 5,800 or 6,000 RPM?=20 Note that the car engine has short runners for high RPM and valving to = lengthen the runners for low RPM. You might even say that low RPM is = where the airplane engine runs all of the time. This should be easy. = That length thing has to do with tuned length, or a pipe organ effect.=20 And our motorcycle friend above shows us that in order to fill out the = mid range,(right where airplane engines run) you need to fill in part of = the intake runners.=20 So folks are making errors at both ends of the runner. The Throttle = body is so big that the last 1/3 to 1/4 of opening has no affect on RPM. = Fortunately this has nearly no affect on HP. At the engine end of the = runner just as in the stock intake manifold the runner needs to be = smaller just as it mates with the block. So the highest flow velocity is = right at the port face.=20 The rotary has a problem that involves the bowl shape below the = opening into the engine, valved by the sides of the rotor. In order to = get the valve timing we need, that bowl is too big (Too much volume). = Some folks fill this in a bit with epoxy products. Some folks make it = worse by increasing the port timing but that makes the bowl volume = increase. The bowl volume causes the velocity to drop right where we = want the highest velocity.=20 Some folks make Periphery port engines with 2" tubing run from some = distance that seems to make sense. This is a big help at RPM above where = you can use it for anything. So at RPM lower than the ideal to take = advantage of the Pport, there is less HP than a side port engine.=20 The opening into the housing with a Pport is usually a round hole. Not = ideal. Later intake opening and earlier closing give you more mid range. = The 2 inch pipe flattened slightly, or a dart removed to reduce the ID = about 15% or a bit more. would keep the velocity high, where it needs to = be high. The best HP should be just before the top speed, so you can = lean away power and heat to get down to cruise RPM.=20 Like the racer you want to be first to your top speed. If you have to = pull off throttle to stay at cruise RPM, add some prop and test again. = The engine will make power to well past 9,000 RPM in street trim, if the = breathing is available.=20 If you want to go real fast, cool the oil. A 12-A can do 310 HP at 10,700 RPM breathing through two 44MM holes. = My side port 12-As can do 250 HP at 9,400 RPM breathing through two 38MM = holes. My intake manifold gasket is stock. The runners at the port face = are the street diameter and shape. A 12-A is 2,292 CCs, a 13-B is = 2,606CCs. These engines are not dynoed below 7,000 RPM, because they = have no power at all below that RPM it is pointless to test there. They = are towed to the false grid with little tractors because they have no = torque at all and they idle at 2,200 RPM. So if you keep building racing engines and puting them into airplanes = that operate below the bottom of the power band of the engine, why do = you do that? Doctor, Doctor, it hurts when I do that. Quit doing that. = Of course I could be completely wrong. Lynn E. Hanover ------=_NextPart_000_0047_01CACD8E.0737ADA0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
The nice thing about a 2" runner dia P Port is that if doesn't make = power=20 at the desired rpm you could place a linner in the runners to reduce the = dia.  A liitle harder to increase the runner dia without = disassembly. =20 Thisof course depends on how many bends are in the runners.
 
Joe Berki
 
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Saturday, March 27, 2010 = 1:40=20 AM
Subject: [FlyRotary] Re: P-Port = performance

In a message dated 3/26/2010 8:58:41 PM Eastern Standard Time, lendich@aanet.com.au = writes:

=E2=80=9Cthat = things that=20 work in one application (like Rx-7 racing) just great - may well = suck in=20 another application.=E2=80=9D

 

Or not = suck=20 enough=E2=80=A6.  ;)

 

Neilk

Here is some more stuff to read, since none of you are = building right=20 now.
 
http://moto= tuneusa.com/think_fast_intake_porting.htm
 
This fellow fills in some cross section on the intake runners = of big=20 engine street and road race bikes.
 
Even the factory people fall in love with maximum HP numbers = to sell=20 bikes. The big numbers at the top RPM require big intake runners. Big = intake=20 runners means high flow velocity will be at astoundingly high RPM. = This means=20 the reverse will be available at mid and lower RPM. So, the rider is = beaten=20 silly on the road course by some weekend nitwit with a smaller engine, = that=20 appears to be stock. He obviously has less maximum HP, but seems to be = doing=20 quite well with his setup.
 
Because.......
 
The smaller engine has good torque and HP at lower and mid = range RPM.=20 Maybe he is not as fast at the end of the long straightaway, but he = seems to=20 get to  his top speed much sooner than the new bike with the = bigger=20 engine. And in road racing and drag racing, it is the first person to = his top=20 speed that wins, not always the highest top speed.
 
Think gear ratio spreads, and area under the curve when you = graph HP.=20
 
Racing engines and airplane engines are the same engines. = Some racing=20 organizations even use rev limiters to equalize competition between = car brands=20 to keep the racing interesting. So you have to imagine that your club, = be it=20 hair club for men or the home built airplane club has a rule about top = RPM.=20
 
Of course the club has no such rule, but Mother nature does = have such=20 a rule. It has to do with the tip speed of propellers. So once you = calculate=20 the ratio of your reduction unit, you know how fast you can turn up = your=20 engine. And it isn't very much RPM.
 
So now you are unhappy with the torque of the car engine that = had=20 good torque at 2,500 RPM in the street car, and now you want the best = torque=20 to be where? 5,000 RPM with best HP at 5,800 or 6,000 RPM?
 
Note that the car engine has short runners for high RPM and = valving=20 to lengthen the runners for low RPM. You might even say that low RPM = is where=20 the airplane engine runs all of the time. This should be easy. That = length=20 thing has to do with tuned length, or a pipe organ effect.
 
And our motorcycle friend above shows us that in order to = fill out=20 the mid range,(right where airplane engines run) you need to fill in = part of=20 the intake runners.
 
So folks are making errors at both ends of the runner. The = Throttle=20 body is so big that the last 1/3 to 1/4 of opening has no affect on = RPM.=20 Fortunately this has nearly no affect on HP. At the engine end of = the=20 runner just as in the stock intake manifold the runner needs to be = smaller=20 just as it mates with the block. So the highest flow velocity is right = at the=20 port face.
 
The rotary has a problem that involves the bowl shape below = the=20 opening into the engine, valved by the sides of the rotor. In order to = get the=20 valve timing we need, that bowl is too big (Too much volume). Some = folks fill=20 this in a bit with epoxy products. Some folks make it worse by = increasing the=20 port timing but that makes the bowl volume increase. The bowl volume = causes=20 the velocity to drop right where we want the highest velocity. =
 
Some folks make Periphery port engines with 2" tubing run = from some=20 distance that seems to make sense. This is a big help at RPM above = where you=20 can use it for anything. So at RPM lower than the ideal to take = advantage of=20 the Pport, there is less HP than a side port engine.
 
The opening into the housing with a Pport is usually a round = hole.=20 Not ideal. Later intake opening and earlier closing give you more mid = range.=20 The 2 inch pipe flattened slightly, or a dart removed to reduce the ID = about=20 15% or a bit more. would keep the velocity high, where it needs to be = high.=20 The best HP should be just before the top speed, so you can lean away = power=20 and heat to get down to cruise RPM.
 
Like the racer you want to be first to your top speed. If you = have to=20 pull off throttle to stay at cruise RPM, add some prop and test again. = The=20 engine will make power to well past 9,000 RPM in street trim, if the = breathing=20 is available.
 
If you want to go real fast, cool the oil.
 
A 12-A can do 310 HP at 10,700 RPM breathing through two 44MM = holes.=20 My side port 12-As can do 250 HP at 9,400 RPM breathing through two = 38MM=20 holes. My intake manifold gasket is stock. The runners at the port = face are=20 the street diameter and shape. A 12-A is 2,292 CCs, a 13-B is = 2,606CCs. These=20 engines are not dynoed below 7,000 RPM, because they have no power at = all=20 below that RPM it is pointless to test there. They are towed to the = false grid=20 with little tractors because they have no torque  at all and they = idle at=20 2,200 RPM.
 
So if you keep building racing engines and puting them = into=20 airplanes that operate below the bottom of the power band of the = engine, why=20 do you do that? Doctor, Doctor, it hurts when I do that. Quit doing=20 that. Of course I could be completely wrong.
 
Lynn E. = Hanover   
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