X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from outbound-mail.vgs.untd.com ([64.136.55.15] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with SMTP id 5082287 for flyrotary@lancaironline.net; Thu, 04 Aug 2011 19:47:32 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.55.15; envelope-from=alwick@juno.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=juno.com; s=alpha; t=1312501617; bh=47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=; l=0; h=Message-ID:From:To:Subject:Date:Content-Type; b=ePQ8yy/DDC9HHzuPSAxIOwpXcK6385FyElfJhXW6/GFGdfDmn4AwcAtBDysokhnq2 Jtbzp43BtQX8pFUQIk/KEoMVVh++AOQ0SSusOAi0fiHb5Xp5o/F7rzsKXBSM5+Iy53 r0H9acuel/L1+AM7Bd6xfP1RWs4eRfC0dmOjGgVo= Received: from Penny (50-39-167-80.bvtn.or.frontiernet.net [50.39.167.80]) by smtpout01.vgs.untd.com with SMTP id AABHDYM5SAD9CT6J for (sender ); Thu, 4 Aug 2011 16:46:56 -0700 (PDT) Message-ID: <8D9207A7D62945DC8DAA054F9C38197A@Penny> From: "Al Wick" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Water pump pulley departed in-flight Date: Thu, 4 Aug 2011 16:46:51 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0289_01CC52C6.1C553450" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 X-UNTD-BodySize: 7232 X-ContentStamp: 15:7:963635128 X-MAIL-INFO:0f51a9d13830194574798038d9c915d9c10034a1b910ddf47401f564a53d958095e5408405cd09d510e02020ade9e164d4a09149d060019070d070e1f9709901b070a4b0498d941d74c994b4 X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkGyG2d2CuOX7hb9EjRcMRU9WKizzaDuJtg== X-UNTD-Peer-Info: 10.181.42.31|smtpout01.vgs.untd.com|smtpout01.vgs.untd.com|alwick@juno.com This is a multi-part message in MIME format. ------=_NextPart_000_0289_01CC52C6.1C553450 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Excellent analysis Lynn. Very strange design for a pulley to have the = load so far from the bolts. Tremendous moment on that thin sheet metal. = Easy to over tighten the belt and then you are screwed.=20 More fasteners, fine. But I'd sure focus on measuring belt tension.=20 -al wick ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Thursday, August 04, 2011 7:35 AM Subject: [FlyRotary] Re: Water pump pulley departed in-flight Notice the offset of the pulley vice the flange centerline. The bolts = are in shear for driving forces (very light) and in bending for belt = tension (slightly higher load) so the little guys are working hard, and = more bolts is a better answer. Racers run the single belt with the stock = alternator location, and just about 30% of the water pump pulley engaged = with no problems at all, so loads are light. I use bolts in all 8 holes = with Locktite. If your pumps have only 4 holes, add 4 more and tap. And = actually measure belt tension. There are stock two sheave water pump = pulleys, where you run the alternator and, or, air conditioning with a = two sheave crank pulley. And there is a belt length that you can run the = water pump from the Mazda Competition pulley (smaller diameter) with no = idler at all and perfect belt tension.=20 No pulley failures since that first one in 1980, (with 4 bolts). Lynn E. Hanover =20 In a message dated 8/4/2011 7:59:53 A.M. Paraguay Standard Time, = jwhaley@datacast.com writes: There are only four small bolts holding that thing in place = =E2=80=A6 noticed in Haynes pictures this morning that some have four = studs and four bolts =E2=80=A6 guess the studs are for adding a second = pulley? =E2=80=93 but they would also add extra drive surface area. I = think I put those bolts on with standard loctite but am not 100% = certain. Anyway now I=E2=80=99m wondering if my restrictor plate, = loading the pump, may have contributed to more vibration or is this just = coincidence =E2=80=A6=20 Jeff ------=_NextPart_000_0289_01CC52C6.1C553450 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Excellent analysis Lynn. Very strange design for a = pulley to=20 have the load so far from the bolts. Tremendous moment on that thin = sheet metal.=20 Easy to over tighten the belt and then you are screwed.
 
More fasteners, fine. But I'd sure focus on = measuring belt=20 tension.
 
-al wick
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Thursday, August 04, 2011 = 7:35=20 AM
Subject: [FlyRotary] Re: Water = pump=20 pulley departed in-flight

Notice the offset of the pulley vice the flange centerline. The = bolts are=20 in shear for driving forces (very light) and in bending for belt = tension=20 (slightly higher load) so the little guys are working hard, and more = bolts is=20 a better answer. Racers run the single belt with the stock alternator=20 location, and just about 30% of the water pump pulley engaged with no = problems=20 at all, so loads are light. I use bolts in all 8 holes with Locktite. = If your=20 pumps have only 4 holes, add 4 more and tap. And actually measure belt = tension. There are stock two sheave water pump pulleys, where you run = the=20 alternator and, or, air conditioning with a two sheave crank pulley. = And there=20 is a belt length that you can run the water pump from the Mazda = Competition=20 pulley (smaller diameter) with no idler at all and perfect belt = tension.=20
 
No pulley failures since that first one in 1980, (with 4 = bolts).
 
Lynn E. Hanover   
 
 
 
In a message dated 8/4/2011 7:59:53 A.M. Paraguay Standard Time,=20 jwhaley@datacast.com writes:

There=20 are only four small bolts holding that thing in place =E2=80=A6 = noticed in Haynes=20 pictures this morning that some have four studs and four bolts = =E2=80=A6 guess the=20 studs are for adding a second pulley?=20 =E2=80=93 but they would also add extra drive surface area. =  I=20 think I put those bolts on with standard loctite but am not 100%=20 certain.  Anyway now I=E2=80=99m wondering if my restrictor = plate, loading the=20 pump, may have contributed to more vibration or is this just = coincidence=20 =E2=80=A6=20

Jeff

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