X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4126318 for flyrotary@lancaironline.net; Mon, 15 Feb 2010 22:58:10 -0500 Received-SPF: pass receiver=logan.com; client-ip=71.74.56.122; envelope-from=clouduster@austin.rr.com Return-Path: X-Authority-Analysis: v=1.0 c=1 a=AWMMCXnlpr96N9Act9EA:9 a=W_iyrFOFDYIhq8kJBQIA:7 a=htPem9LAMV2Pkan0MvOmxQoDOIAA:4 a=jShzCaYlAEkWFe4c:21 a=yCO5ueufNnayaoVC:21 a=4PR2P7QzAAAA:8 a=Qg3Xtk5I2rDAbejsVOwA:9 a=ZUab9mBsUqIsPazDKPgA:7 a=G8mDx7Z6eTIPFkG_MiGt5zwU3dYA:4 a=djSSOgbfo6cA:10 X-Cloudmark-Score: 0 X-Originating-IP: 66.25.157.35 Received: from [66.25.157.35] ([66.25.157.35:3762] helo=[10.0.0.99]) by hrndva-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id 8F/E6-06643-FA71A7B4; Tue, 16 Feb 2010 03:57:35 +0000 Message-ID: <4B7A17AF.4010706@austin.rr.com> Date: Mon, 15 Feb 2010 21:57:35 -0600 From: Dennis Haverlah User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Air Pump References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------010608000500070802000406" This is a multi-part message in MIME format. --------------010608000500070802000406 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit 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" = 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 > > --------------010608000500070802000406 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit 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"  = 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 


--------------010608000500070802000406--