Return-Path: Received: from imo-d21.mx.aol.com ([205.188.144.207] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 776097 for flyrotary@lancaironline.net; Tue, 08 Mar 2005 20:14:39 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.207; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-d21.mx.aol.com (mail_out_v37_r3.8.) id q.5b.651b1369 (15889) for ; Tue, 8 Mar 2005 20:13:45 -0500 (EST) Received: from aol.com (mow-d14.webmail.aol.com [205.188.139.130]) by air-id08.mx.aol.com (v104.18) with ESMTP id MAILINID84-3e11422e4dc93b4; Tue, 08 Mar 2005 20:13:45 -0500 Date: Tue, 08 Mar 2005 20:13:45 -0500 From: WRJJRS@aol.com To: flyrotary@lancaironline.net ("Rotary motors in aircraft") Subject: Re: [FlyRotary] Re: Tangential muffler MIME-Version: 1.0 Message-ID: <7B508BB8.19B0AA79.00051B7E@aol.com> X-Mailer: Atlas Mailer 2.0 X-AOL-IP: 66.127.99.234 X-AOL-Language: english Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Jerry, With regards to the VAM as was run at Tracy's, the design is ABSOLUTELY DEPENDENT on the tail pipe. The test at Tracy's ran the pipe with the tail pipe removed so the pipe would fit on Tracy's test stand. This was dumb as the cool tube was designed to form a venturi in the TAIL PIPE to draw in the cool air. Your test installation was better, but by that time Paul L was advising you, (incorrectly IMHO) that the idea was crappy. The VAM will work, but you should run a tail pipe and a thicker one right at the junction would be better. Your cool tube will help and isn't as finicky. Blending the cool air and exhaust streams should help quiet the muffler more but you have to do it carefully. Bill Jepson In a message dated 3/8/2005 4:14:12 PM Eastern Standard Time, Jerry Hey writes: >Ed, you are referring to the VAM which did not have a cooling tube,   >just an open end.    It was very loud, I understand.   It was  in   >looking at the VAM that Ed Klepeis and I finally asked each other, what   >if we weld a tube in there?  We still think it is a good idea.  The   >large diameter is also important.  The idea is that the exhaust gases   >will lose heat and energy (sound) as they expand within the can.  Also,   >note the exit pipe (rectangular, 1.75 x 4) is  has a much larger area   >then the two 2" o.d. pipes coming out of the engine.   The idea is to   >create a completely free flowing exhaust  in which the exhaust gases   >become very disorganize as they expand and cool.    Jerry > > > > >On Tuesday, March 8, 2005, at 03:50  PM, Ed Anderson wrote: > >> Well, I hope it works out.  A somewhat similar muffler (although not as >> large in diameter) with a cooling tube has been tried.  It was fired   >> up at >> Tracy's, it is my opinion that the design failed to mute the exhaust   >> very >> much.  But, not certain how much the two designs have in common other   >> than >> appearances.   Seeing as the exhaust BTU is equivalent to approx twice   >>  the >> heat discharged through the radiators and mufflers together, it is my >> opinion, that its going to take a LOT of cooling air to make any   >> difference >> in temps of the oven.  However, I would love to see it work, I've got   >> the >> room - just can't take the heat. {:>) >> >> >> Ed >> >> ----- Original Message ----- >> From: "Jerry Hey" >> To: "Rotary motors in aircraft" >> Sent: Tuesday, March 08, 2005 3:33 PM >> Subject: [FlyRotary] Re: Tangential muffler >> >> >>> Thanks for  your comment Ed.  The cool tube is intended to extract a >>> lot of that heat and pump it overboard.   We shall soon see if it   >>> works >>> as Bob White will be  running his engine soon.  I got my fingers >>> crossed. >>> >>> >>> >>> >>> On Tuesday, March 8, 2005, at 03:17  PM, Ed Anderson wrote: >>> >>>> Jerry, Tracy Crook flew with a similar Tangential muffler for a   >>>> number >>>> of >>>> hours.  The neat thing is it does fit under the cowl and suppress   >>>> sound >>>> nicely, the un-neat thing is it acts like a large oven under the cowl >>>> and >>>> keeps cowl temps highly elevated.  I am fairly certain that is why >>>> Tracy >>>> removed it. >>>> >>>> Ed A >>>> >>>> >>>> ----- Original Message ----- >>>> From: "Jerry Hey" >>>> To: "Rotary motors in aircraft" >>>> Sent: Tuesday, March 08, 2005 3:01 PM >>>> Subject: [FlyRotary] Tangential muffler >>>> >>>> >>>>> From the "other" list comes the report that someone has tested a >>>>> similar exhaust system to what I have been building on his   >>>>> PowerSport >>>>> p >>>>> ported  engine.  .  He reports the muffler worked well to quiet the >>>>> exhaust note and that the engine seemed to breath freely.  The neat >>>>> thing about this exhaust system is that it fits inside the cowl. >>>>> Here are a couple of photos showing the muffler on a Mustang 2. The >>>>> muffler is 6" o.d. x 10 inches long. Construction is 321 16 gage. >>>>> The cool tube running through the center is intended to cool the >>>>> exhaust gas. Fresh air is plumbed through it.    The engine mount is >>>>> the S-beam.      Jerry >>>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> -- >>>> ----- >>>> ---- >>>> >>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> -- >>>> ----- >>>> ---- >>>> >>>> >>>>>>>  Homepage:  http://www.flyrotary.com/ >>>>>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html >>>>> >>>> >>>> >>>> >>>>>>  Homepage:  http://www.flyrotary.com/ >>>>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html >>>> >>> >>> >>>>>  Homepage:  http://www.flyrotary.com/ >>>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html >>> >> >> >> >>>>  Homepage:  http://www.flyrotary.com/ >>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html >> > > >>>  Homepage:  http://www.flyrotary.com/ >>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html >