X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-m25.mx.aol.com ([64.12.137.6] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2604340 for flyrotary@lancaironline.net; Tue, 18 Dec 2007 19:01:30 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.6; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m25.mx.aol.com (mail_out_v38_r9.3.) id q.c34.21ac4aef (37128) for ; Tue, 18 Dec 2007 19:00:37 -0500 (EST) Received: from WEBMAIL-MC14 (webmail-mc14.webmail.aol.com [64.12.170.91]) by cia-ma02.mx.aol.com (v121.4) with ESMTP id MAILCIAMA022-910847685f2442; Tue, 18 Dec 2007 19:00:36 -0500 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: Supercharging Date: Tue, 18 Dec 2007 19:00:36 -0500 X-AOL-IP: 65.161.241.3 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: wrjjrs@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CA0FE951774959_D08_2C71_WEBMAIL-MC14.sysops.aol.com" X-Mailer: AOL Webmail 33161-STANDARD Received: from 65.161.241.3 by WEBMAIL-MC14.sysops.aol.com (64.12.170.91) with HTTP (WebMailUI); Tue, 18 Dec 2007 19:00:36 -0500 Message-Id: <8CA0FE951774959-D08-15C2@WEBMAIL-MC14.sysops.aol.com> X-Spam-Flag: NO ----------MB_8CA0FE951774959_D08_2C71_WEBMAIL-MC14.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" Ernest, Unless you get the unit well balanced you will probably run into bearing problems. If you mount the impeller directly you will require?a good alignment at the connection, preferably a taper. You will need to keep the housing reasonably close or you won't make much pressure. The standard blower has a fairly tight scroll, and you will need to duplicate that or use that to make the same sort of pressure. the best method would be to transplant the housing. Be? sure the plastic is up to the in-cowl temperature. I don't know how well it will work, but to make it work well at all you would have to treat it like any other centrifugal supercharger. The russian inline 4 and 6 cylinders mount a supercharger like you are talking about. the name slips my mind right now. Certified though. They use a 2 speed gearbox on some of them to allow cruise or power boost level. Bill Jepson -----Original Message----- From: Ernest Christley To: Rotary motors in aircraft Sent: Tue, 18 Dec 2007 2:51 pm Subject: [FlyRotary] Re: Supercharging wrjjrs@aol.com wrote:? > Ernest,? > All that the leaf blower is is the compressor scroll of a turbo > charger. many of the aircraft superchargers, circa WW2 used a > centrifugal supercharger which is exactly what you are describing. > Think you will find it more trouble than it's worth. Mainly due to > breakage of the parts at high RPMs. You will have to design your own > drive, and it is a drive even if simply a shaft connection. You would > probably find a belt driven centrifugal supercharger and using a > underdriven (reducing) system. You will find a supercharged 13B will > make 200 HP very easily.? > Bill Jepson Ed, how many Hp would be required to accelerate 307CFM of air from 0 to 150MPH? That would be the extent of the power that the fan blades would have to absorb, wouldn't it? Would there be a major drag component?? ? The drive is already designed and built, but what parts do you think might break, Bill? It's a compressor wheel bolted up to the flywheel. Should I expect to see problems with it shedding blades? I've looked into the leaf blower components, specifically because they were designed to run at the RPM we're looking at. Literally, trying not to reinvent the wheel. I'm assuming that they can take the RPM, since it is an industrial component that workers carry on their backs.? ? The shroud is the bellhousing. Not optimum, but sturdy and simple. I will probably have to add some extra aluminum sheet to keep the housing tight, but I don't see having much problems with that part.? ? Like Ed said, it's just an experiment at this point. I'm really just guessing that it will be worthwhile, but it's just such a simple mod that I've got to try. The labor, weight and dollar investments are all about right. I just have to see how much payback there is while avoiding throwing pieces of metal around.? ? --? Homepage: http://www.flyrotary.com/? Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html? ________________________________________________________________________ More new features than ever. Check out the new AOL Mail ! - http://webmail.aol.com ----------MB_8CA0FE951774959_D08_2C71_WEBMAIL-MC14.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/html; charset="us-ascii"
Ernest,
Unless you get the unit well balanced you will probably run into bearing problems. If you mount the impeller directly you will require a good alignment at the connection, preferably a taper. You will need to keep the housing reasonably close or you won't make much pressure. The standard blower has a fairly tight scroll, and you will need to duplicate that or use that to make the same sort of pressure. the best method would be to transplant the housing. Be  sure the plastic is up to the in-cowl temperature. I don't know how well it will work, but to make it work well at all you would have to treat it like any other centrifugal supercharger. The russian inline 4 and 6 cylinders mount a supercharger like you are talking about. the name slips my mind right now. Certified though. They use a 2 speed gearbox on some of them to allow cruise or power boost level.
Bill Jepson


-----Original Message-----
From: Ernest Christley <echristley@nc.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Tue, 18 Dec 2007 2:51 pm
Subject: [FlyRotary] Re: Supercharging

wrjjrs@aol.com wrote: 
> Ernest, 
> All that the leaf blower is is the compressor scroll of a turbo > charger. many of the aircraft superchargers, circa WW2 used a > centrifugal supercharger which is exactly what you are describing. > Think you will find it more trouble than it's worth. Mainly due to > breakage of the parts at high RPMs. You will have to design your own > drive, and it is a drive even if simply a shaft connection. You would > probably find a belt driven centrifugal supercharger and using a > underdriven (reducing) system. You will find a supercharged 13B will > make 200 HP very easily. 
> Bill Jepson Ed, how many Hp would be required to accelerate 307CFM of air from 0 to 150MPH? That would be the extent of the power that the fan blades would have to absorb, wouldn't it? Would there be a major drag component? 
 
The drive is already designed and built, but what parts do you think might break, Bill? It's a compressor wheel bolted up to the flywheel. Should I expect to see problems with it shedding blades? I've looked into the leaf blower components, specifically because they were designed to run at the RPM we're looking at. Literally, trying not to reinvent the wheel. I'm assuming that they can take the RPM, since it is an industrial component that workers carry on their backs. 
 
The shroud is the bellhousing. Not optimum, but sturdy and simple. I will probably have to add some extra aluminum sheet to keep the housing tight, but I don't see having much problems with that part. 
 
Like Ed said, it's just an experiment at this point. I'm really just guessing that it will be worthwhile, but it's just such a simple mod that I've got to try. The labor, weight and dollar investments are all about right. I just have to see how much payback there is while avoiding throwing pieces of metal around. 
 
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