X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-mb02.mx.aol.com ([64.12.207.163] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4180585 for flyrotary@lancaironline.net; Sat, 27 Mar 2010 02:41:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.207.163; envelope-from=Lehanover@aol.com Received: from imo-da02.mx.aol.com (imo-da02.mx.aol.com [205.188.169.200]) by imr-mb02.mx.aol.com (8.14.1/8.14.1) with ESMTP id o2R6ee22001019 for ; Sat, 27 Mar 2010 02:40:40 -0400 Received: from Lehanover@aol.com by imo-da02.mx.aol.com (mail_out_v42.9.) id q.c80.6e8bc0a9 (37541) for ; Sat, 27 Mar 2010 02:40:36 -0400 (EDT) Received: from magic-d25.mail.aol.com (magic-d25.mail.aol.com [172.19.146.159]) by cia-mb02.mx.aol.com (v127_r1.2) with ESMTP id MAILCIAMB022-92a54bada86415a; Sat, 27 Mar 2010 02:40:36 -0400 From: Lehanover@aol.com Message-ID: <5f66d.6fe3a5fe.38df0264@aol.com> Date: Sat, 27 Mar 2010 02:40:36 EDT Subject: Re: [FlyRotary] Re: P-Port performance To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_5f66d.6fe3a5fe.38df0264_boundary" X-Mailer: 9.0 for Windows sub 5101 X-AOL-ORIG-IP: 72.187.199.116 X-AOL-IP: 172.19.146.159 X-Spam-Flag:NO X-AOL-SENDER: Lehanover@aol.com --part1_5f66d.6fe3a5fe.38df0264_boundary Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en =20 In a message dated 3/26/2010 8:58:41 PM Eastern Standard Time,=20 lendich@aanet.com.au writes: =E2=80=9Cthat things that work in one application (like Rx-7 racing) just= great -=20 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 =20 _http://mototuneusa.com/think_fast_intake_porting.htm_=20 (http://mototuneusa.com/think_fast_intake_porting.htm)=20 =20 This fellow fills in some cross section on the intake runners of big engin= e=20 street and road race bikes. =20 Even the factory people fall in love with maximum HP numbers to sell bikes= .=20 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 me= ans the=20 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, tha= t=20 appears to be stock. He obviously has less maximum HP, but seems to be doi= ng=20 quite well with his setup.=20 =20 Because....... =20 The smaller engine has good torque and HP at lower and mid range RPM. Mayb= e=20 he is not as fast at the end of the long straightaway, but he seems to get= =20 to his top speed much sooner than the new bike with the bigger engine. An= d=20 in road racing and drag racing, it is the first person to his top speed th= at=20 wins, not always the highest top speed.=20 =20 Think gear ratio spreads, and area under the curve when you graph HP.=20 =20 Racing engines and airplane engines are the same engines. Some racing=20 organizations even use rev limiters to equalize competition between car br= ands to=20 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 =20 Of course the club has no such rule, but Mother nature does have such a=20 rule. It has to do with the tip speed of propellers. So once you calculate= the=20 ratio of your reduction unit, you know how fast you can turn up your engin= e.=20 And it isn't very much RPM.=20 =20 So now you are unhappy with the torque of the car engine that had good=20 torque at 2,500 RPM in the street car, and now you want the best torque to= be=20 where? 5,000 RPM with best HP at 5,800 or 6,000 RPM?=20 =20 Note that the car engine has short runners for high RPM and valving to=20 lengthen the runners for low RPM. You might even say that low RPM is where= the=20 airplane engine runs all of the time. This should be easy. That length thi= ng=20 has to do with tuned length, or a pipe organ effect.=20 =20 And our motorcycle friend above shows us that in order to fill out the mid= =20 range,(right where airplane engines run) you need to fill in part of the= =20 intake runners.=20 =20 So folks are making errors at both ends of the runner. The Throttle body= is=20 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 runn= er just as=20 in the stock intake manifold the runner needs to be smaller just as it mat= es=20 with the block. So the highest flow velocity is right at the port face.=20 =20 The rotary has a problem that involves the bowl shape below the opening=20 into the engine, valved by the sides of the rotor. In order to get the val= ve=20 timing we need, that bowl is too big (Too much volume). Some folks fill th= is=20 in a bit with epoxy products. Some folks make it worse by increasing the= port=20 timing but that makes the bowl volume increase. The bowl volume causes the= =20 velocity to drop right where we want the highest velocity.=20 =20 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 can=20 use it for anything. So at RPM lower than the ideal to take advantage of= the=20 Pport, there is less HP than a side port engine.=20 =20 The opening into the housing with a Pport is usually a round hole. Not=20 ideal. Later intake opening and earlier closing give you more mid range.= The 2=20 inch pipe flattened slightly, or a dart removed to reduce the ID about 15%= or=20 a bit more. would keep the velocity high, where it needs to be high. The= =20 best HP should be just before the top speed, so you can lean away power an= d=20 heat to get down to cruise RPM.=20 =20 Like the racer you want to be first to your top speed. If you have to pull= =20 off throttle to stay at cruise RPM, add some prop and test again. The engi= ne=20 will make power to well past 9,000 RPM in street trim, if the breathing is= =20 available.=20 =20 If you want to go real fast, cool the oil. =20 A 12-A can do 310 HP at 10,700 RPM breathing through two 44MM holes. My=20 side port 12-As can do 250 HP at 9,400 RPM breathing through two 38MM hole= s. My=20 intake manifold gasket is stock. The runners at the port face are the=20 street diameter and shape. A 12-A is 2,292 CCs, a 13-B is 2,606CCs. These= engines=20 are not dynoed below 7,000 RPM, because they have no power at all below=20 that RPM it is pointless to test there. They are towed to the false grid= with=20 little tractors because they have no torque at all and they idle at 2,200= =20 RPM. =20 So if you keep building racing engines and puting them into airplanes that= =20 operate below the bottom of the power band of the engine, why do you do=20 that? Doctor, Doctor, it hurts when I do that. Quit doing that. Of course= I=20 could be completely wrong. =20 Lynn E. Hanover =20 --part1_5f66d.6fe3a5fe.38df0264_boundary Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
In a message dated 3/26/2010 8:58:41 PM Eastern Standard Time, lendic= h@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

&= nbsp;

Or not= suck enough=E2=80=A6.  ;)

&= nbsp;

Neilk<= /SPAN>

Here is some more stuff to read, since none of you are building= right now.
 
= 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. Bi= g 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 sm= aller engine, that appears to be stock. He obviously has less maximum HP,= but seems to be doing quite well with his setup.
 
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 th= e bigger engine. And in road racing and drag racing, it is the first perso= n to his top speed that wins, not always the highest top speed.
 
Think gear ratio spreads, and area under the curve when you graph= HP.
 
Racing engines and airplane engines are the same engines. Some ra= cing organizations even use rev limiters to equalize competition between= car brands to keep the racing interesting. So you have to imagine that yo= ur club, be it hair club for men or the home built airplane club has a rul= e about top RPM.
 
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 tur= n up your engine. And it isn't very much RPM.
 
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 tor= que 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 valvi= ng 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.
 
And our motorcycle friend above shows us that in order to fill ou= t the mid range,(right where airplane engines run) you need to fill in par= t of the intake runners.
 
So folks are making errors at both ends of the runner. The Thrott= le 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 sm= aller just as it mates with the block. So the highest flow velocity is rig= ht at the port face.
 
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 ge= t 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.
 
Some folks make Periphery port engines with 2" tubing run from so= me distance that seems to make sense. This is a big help at RPM above wher= e you can use it for anything. So at RPM lower than the ideal to take adva= ntage of the Pport, there is less HP than a side port engine.
 
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 ra= nge. 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.
 
Like the racer you want to be first to your top speed. If you hav= e 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.
 
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 hol= es. My side port 12-As can do 250 HP at 9,400 RPM breathing through two 38= MM 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 2,606CC= s. These engines are not dynoed below 7,000 RPM, because they have no powe= r 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   
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