X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost02.isp.att.net ([204.127.217.102] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4126350 for flyrotary@lancaironline.net; Mon, 15 Feb 2010 23:35:43 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.217.102; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-230-68-40.mco.bellsouth.net[74.230.68.40]) by isp.att.net (frfwmhc02) with SMTP id <20100216043507H0200d2d14e>; Tue, 16 Feb 2010 04:35:07 +0000 X-Originating-IP: [74.230.68.40] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Air Pump Date: Mon, 15 Feb 2010 23:35:09 -0500 Message-ID: <12FE37264AF94F39BF11D2C307311356@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0026_01CAAE97.834F56B0" X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcquvENR+wt3De0RSVi5okPvayBYAgABFNqQ X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 This is a multi-part message in MIME format. ------=_NextPart_000_0026_01CAAE97.834F56B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dennis, I think the Lycosaurous people get about =BE to 1 inch of improvement = with ram air at a couple of hundred mph. That seems consistant with the airspeed = of the air from your blower. Your idea to attach a centrifugal blower up = to the pulley is a good one. You could make it belt driven like the = alternator and with a small pulley, crank it up to about 12K rpm! Pictures?? Bill B=20 =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Dennis Haverlah Sent: Monday, February 15, 2010 10:58 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Air Pump Bill: =20 Thanks to my younger brother who was brave enough (use younger brothers = for dangerous stuff) to operate the leaf blower I ran the leaf blower test = for the group. I used a fairly new hand held Echo leaf blower Model PB 251 = I "borrowed" from my neighbors hangar. =20 Specs - 25 cc 2 stroke,=20 Average Air Volume (cfm-pipe) 390 Average Air Volume (cfm-housing) 509 Maximum Air Speed (mph-pipe) 145 No information on rpm's at these data points were listed. I would guess that the 2 stroke engines are operated between 6000 and 8000 rpm. but I'd like to have real rpm data. Four tests were conducted as shown below. Local air pressure was 30.2 = in Baro. - 0.5 in for 1000" =3D 29.7 in hg. air pressure at field = elevation. Weather was Clear, low humidity and 53 deg. OAT. All tests were at WOT. Pictures are attached for each test. Note the 180 deg. bend in the Scat tubing during the (C) test. The (C) test picture was taken after we had taken the Scat tube but my brother was holding it in place. Test condition Static max. RPM Manifold Pressure Engine Temp. (A) Standard intake, 5870 28.9 Barely warm=20 air filter etc. (B) W/O air filter & 5660 28.7 Fully warm prop blast (C) Leaf Blower full 5925 29.9 Fully warm throttle into throttle body - 180 deg turn. (D) Same as (A) 5700 29.0 Fully warm It appears that the blower raised the inlet pressure by 1.2 in Hg. and = the engine rpm increased from 5700 to 5925 rpm. I needed to turn the mixture knob slightly richer with the blower = running to get max. power. Also note that the tube feeding the intake had to make a 180 deg. bend = just before the throttle body. The leaf blower used in this test was the smallest Echo makes. Their = web site lists approximately 15 blowers and the largest is a 63.3 cc 2 = stroke as follows: Average Air Volume (cfm-pipe) 620 Average Air Volume (cfm-housing) 1240 Maximum Air Speed (mph-pipe) 205 My thought is that several blowers are available that probably would = provide the needed blower capacity. =20 I believe we need a system that is adaptable to using Tracy'c RD-1 = drive. I also believe it is not likely a centrifugal blower can be placed between = the engine and gear box because the spacing between the gear box plate and = the engine is about 2.5 inches and the ring gear is approximately in the = middle of the space. If someone is interested in adding a direct drive blower = why not attach it to the rear of the engine with the centrifugal fan = attached to the crankshaft pulley? The fans from the big blowers may have enough capacity to work at our crankshaft speeds. If this could be made to = work it would fit the majority of the rotary installations and be an inexpensive = way to add More Power Scotty. PS I have all the power I need with my DIE intake - if someone can find = a way to build it that may solve most of the power needs. Dennis Haverlah Bill Bradburry wrote: Has anybody ever tried hooking up a leaf blower to the throttle body = inlet and see what that would do to the static rpm and manifold pressure at = WOT? Bill B=20 =20 ------=_NextPart_000_0026_01CAAE97.834F56B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dennis,

I think the Lycosaurous people get about =BE = to 1 inch of improvement with ram air at a couple of hundred mph.=A0 That seems = consistant with the airspeed of the air from your blower.=A0 Your idea to attach a = centrifugal blower up to the pulley is a good one.=A0 You could make it belt driven = like the alternator and with a small pulley, crank it up to about 12K = rpm!

Pictures??

Bill B 

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Dennis Haverlah
Sent: Monday, February = 15, 2010 10:58 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Air Pump

Bill: 
Thanks to my younger brother who was brave enough (use younger brothers = for dangerous stuff) to operate the leaf blower I ran the leaf blower test = for the group.  I used a fairly new hand held Echo leaf blower Model PB 251 =   I "borrowed" from my neighbors hangar. 
Specs - 25 cc 2 stroke,

Average Air Volume = (cfm-pipe)

390

Average Air Volume = (cfm-housing)

509

Maximum Air Speed = (mph-pipe)

145


No information on rpm's at these data points were listed.  I would = guess that the 2 stroke engines are operated between 6000 and
8000 rpm. but I'd like to have real rpm data.

Four tests were conducted as shown below.  Local air pressure was = 30.2 in Baro. - 0.5 in for 1000"  =3D 29.7 in hg. air pressure at = field elevation.
Weather was Clear, low humidity and 53 deg. OAT.  All tests were at = WOT.
Pictures are attached for each test.  Note the 180 deg. bend in the = Scat tubing during the (C) test.
The (C) test picture was taken after we had taken the Scat tube but my = brother was holding it in place.

Test condition               Static max. RPM      Manifold Pressure        Engine Temp.
(A) Standard intake,            =    5870                        28.9                    Barely = warm
      air filter etc.

(B) W/O air filter &          =        5660         =                28.7                    = Fully warm
       prop blast

(C) Leaf Blower full                 5925         =               29.9   =                   Fully = warm
      throttle into throttle
      body - 180 deg turn.

(D) Same as (A)            =            5700                       29.0                     Fully warm

It appears that the blower raised the inlet pressure by 1.2 in Hg. and = the engine rpm increased from 5700 to 5925 rpm.
I needed to turn the mixture knob slightly richer with the blower = running to get max. power.
Also note that the tube feeding the intake had to make a 180 deg. bend = just before the throttle body.

The leaf blower used in this test was the smallest Echo = makes.  Their web site lists approximately 15 blowers and the largest is a 63.3 = cc 2 stroke as follows:

Average Air Volume = (cfm-pipe)

620

Average Air Volume = (cfm-housing)

1240

Maximum Air Speed = (mph-pipe)

205


My thought is that several blowers are available that probably would = provide the needed blower capacity. 
I believe we need a system that is adaptable to using Tracy'c RD-1 = drive.  I also believe it is not likely a centrifugal blower can be placed = between the engine and gear box because the spacing between the gear box plate and = the engine is about 2.5 inches and the ring gear is approximately in the = middle of the space.  If someone is interested in adding a direct drive = blower why not attach it to the rear of the engine with the centrifugal fan = attached to the crankshaft pulley?   The fans from the big = blowers  may have enough capacity to work at our crankshaft speeds.  If this = could be made to work it would fit the majority of the rotary installations = and be an inexpensive way to add More Power Scotty.

PS I have all the power I need with my DIE intake - if someone can find = a way to build it that may solve most of the power needs.

Dennis Haverlah

Bill Bradburry wrote:

Has anybody ever tried hooking up a leaf blower to the throttle body inlet = and see what that would do to the static rpm and manifold pressure at = WOT?

Bill = B 

 

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