Return-Path: Received: from mailout2.pacific.net.au ([61.8.0.85] verified) by logan.com (CommuniGate Pro SMTP 4.2.8) with ESMTP id 602556 for flyrotary@lancaironline.net; Mon, 10 Jan 2005 17:35:59 -0500 Received-SPF: none receiver=logan.com; client-ip=61.8.0.85; envelope-from=peon@pacific.net.au Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout2.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with ESMTP id j0AMZgHn008118 for ; Tue, 11 Jan 2005 09:35:42 +1100 Received: from ar1 (ppp2534.dyn.pacific.net.au [61.8.37.52]) by mailproxy1.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with SMTP id j0AMZXj8011285 for ; Tue, 11 Jan 2005 09:35:35 +1100 Message-ID: <006501c4f764$83eaa600$3425083d@ar1> From: "Leon" To: "Rotary motors in aircraft" References: Subject: Balanced Assemblies was Re: [FlyRotary] 9.7 rotors Date: Tue, 11 Jan 2005 09:34:10 +1100 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0060_01C4F7C0.B45C0ED0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_0060_01C4F7C0.B45C0ED0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Paul, The 9.7:1 rotors are considerably lighter than the 9.4:1 units. If you = are going to use 9.7:1 units, then the best option is to just get the = whole rotating mass re-balanced. You can use the eccentric shaft and = both the counterweights you already have. It is always better to start = with counterweights that are too heavy, rather than try to add weight = to too light counterweights The Balancier will first dynamically balance the lighter rotor of the = pair, and match balance both rotors to the same weight. Then balance = the whole rotating assy by just removing material from the = counterweights by drilling/grinding to get the balance cortrect. This = will give you a superbly smooth motor. . WARNING: If you try swapping counterweights, it's fraught with = pitfalls, and you never really know you have the correct counterweights = until you run the engine (unless the assy has been scrupulously kept = together - the older shafts used to have correspondence numbers stamped = on the so you could tell if they had been swapped). You will need both = the front & rear Series V '89 -91 counter weights, which don't have any = distinguishing part #s or identification marks on them. A nightmare = even if you are experienced. Re-balancing is ALWAYS the best option. What it costs you to have the = whole assembly dynamically balanced, you will save some if not all by = NOT buying or scrounging additional counter weights. Additionally, you = are guaranteed to have a perfectly smooth engine. One has to experience = a really good balance job to appreciate just how smooth Mr Wankel's = Wonderful Whirrler is! Factory motors, while usually pretty good = balance-wise, are balanced to a tolerance, and are often not as smooth = as they can be. Like I said, you have to have experienced it to = understand!! Take the time and the extra bux to do it once and do it = RIGHT! Cheers, Leon ----- Original Message -----=20 From: Paul=20 To: Rotary motors in aircraft=20 Sent: Tuesday, January 11, 2005 3:47 AM Subject: [FlyRotary] 9.7 rotors Hi, fellow rotorary enthusiasts....I need to ask the group a question. = I now have a street ported 4 port turbo engine, into which I was going = to put my 9.4 NA rotors and rotor housings. If I pick up a set of 9.7 = rotors, do I have to change anything else, ie concentric shaft = counterweight, etc, or can I just swap rotors? I have read that you = need the correct balance counterweight, but I assumed that is to balance = the concentric shaft, not the rotors? If I can just swap out rotors, = and it would have no effect on balance or anything else, I would go = ahead with the swap. Thanks in advance for all your replies. Paul = Conner -------------------------------------------------------------------------= ----- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.6.9 - Release Date: 1/6/2005 -------------------------------------------------------------------------= ----- >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0060_01C4F7C0.B45C0ED0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Paul,
 
The 9.7:1 rotors are considerably = lighter than the=20 9.4:1 units.  If you are going to use 9.7:1 units,  then the = best=20 option is to just get the whole rotating mass re-balanced.  You can = use the=20 eccentric shaft and both the counterweights you already have. It is = always=20 better to start with counterweights that are too heavy,  rather = than try to=20 add weight to too light counterweights
 
The Balancier will first dynamically = balance the=20 lighter rotor of the pair,  and match balance both rotors to = the same=20 weight.  Then balance the whole rotating assy by just removing = material from the counterweights by drilling/grinding to get the balance = cortrect. This will give you a superbly smooth motor.  = .
 
WARNING:  If you try swapping=20 counterweights, it's fraught with pitfalls,  and you never = really know=20 you have the correct counterweights until you run the engine (unless the = assy=20 has been scrupulously kept together - the older shafts used to have=20 correspondence numbers stamped on the so you could tell if they had = been=20 swapped).  You will need both the front & rear Series = V '89=20 -91 counter weights,  which don't have any distinguishing part #s = or=20 identification marks on them.  A nightmare even if you are=20 experienced.
 
Re-balancing is ALWAYS the best = option.  What=20 it costs you to have the whole assembly dynamically balanced,  you = will=20 save some if not all by NOT buying or scrounging additional counter = weights.  Additionally,  you are guaranteed to have a = perfectly smooth=20 engine.  One has to experience a really good balance job to = appreciate just=20 how smooth Mr Wankel's Wonderful Whirrler is!  Factory = motors,  while=20 usually pretty good balance-wise,  are balanced to a = tolerance, =20 and are often not as smooth as they can be.  Like I said,  you = have to=20 have experienced it to understand!!  Take the time and the extra = bux to do=20 it once and do it RIGHT!
 
Cheers,
 
Leon
 
----- Original Message -----
From:=20 Paul=20
Sent: Tuesday, January 11, 2005 = 3:47=20 AM
Subject: [FlyRotary] 9.7 = rotors

Hi, fellow rotorary enthusiasts....I = need to ask=20 the group a question.  I now have a street ported 4 port turbo = engine,=20 into which I was going to put my 9.4 NA rotors and rotor = housings.  If I=20 pick up a set of 9.7 rotors, do I have to change anything else, ie = concentric=20 shaft counterweight, etc, or can I just swap rotors?  I have read = that=20 you need the correct balance counterweight, but I assumed that is to = balance=20 the concentric shaft, not the rotors?  If I can just swap out = rotors, and=20 it would have no effect on balance or anything else, I would go ahead = with the=20 swap.  Thanks in advance for all your replies. Paul = Conner

No virus found in this outgoing message.
Checked by AVG=20 Anti-Virus.
Version: 7.0.300 / Virus Database: 265.6.9 - Release = Date:=20 1/6/2005

>>  Homepage: =20 http://www.flyrotary.com/
>>  Archive:  =20 = http://lancaironline.net/lists/flyrotary/List.html
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