X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao09.cox.net ([68.230.241.30] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 970947 for flyrotary@lancaironline.net; Sun, 05 Feb 2006 11:33:06 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.30; envelope-from=ALVentures@cox.net Received: from BigAl ([68.7.14.39]) by fed1rmmtao09.cox.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with ESMTP id <20060205163225.OGB25099.fed1rmmtao09.cox.net@BigAl> for ; Sun, 5 Feb 2006 11:32:25 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: Torque and torque sequence Date: Sun, 5 Feb 2006 08:32:27 -0800 Message-ID: <000001c62a71$c0be3600$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C62A2E.B29AF600" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C62A2E.B29AF600 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Saturday, February 04, 2006 6:28 PM Subject: [FlyRotary] Re: Atkins errors =20 In a message dated 2/4/2006 5:56:30 PM Eastern Standard Time, ALVentures@cox.net writes: A couple of questions: Why are two of the bolts larger? What is the = torque spec on these bolts for the 20B? I seem to recall 26-28 ft-lbs. I = can't get a torque wrench on the bolts without removing the re-drive, engine = mount and flywheel, but I have a pretty well calibrated arm. =20 Al When you add torque to those bolts, the bolts closest to them will go = under torque. =20 So go through the whole torque sequence several times if at all = possible. This has been the case on every engine I have built. =20 Lynn E. Hanover =20 =20 =20 I don't havea Mazda Manual, but generally in a case like this there are = 2 ways to tighten the bolts correctly: =20 a) Tighten 2 opposite bolts until seated - then torque each to spec. All other bolts are tigthtened spreading out from the 2 torqued:=20 e.g. Torque the 2 big bolts then: 1st bolt to left of one big b. - 1st = bolt to the left of the other big b. - 1st bolt to the right of the one big = b. - 1st bolt to the right of the other big b. - 2nd bolt to the left...... = you get the idea. =20 This way you have the pieces flat together on a "centerline" and "lay" = the rest down on each side of this centerline - spreading it out so that no "wrinkles" are created.... =20 b) A stepped sequence is shown in a manual: mostly in cross pattern and something like 10 lb/18lb/26lb =20 =20 Thomas; I understand the niceties of torque sequence; but it would seem that is = all out the window when the engine has been run about 6 hours, many cycles = to full power, and a dozen or more temperature cycles to 200-210 F; all = with the two large bolts loose. As far as I know nothing untoward has = happened, but how can I be sure? =20 Al ------=_NextPart_000_0001_01C62A2E.B29AF600 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
=

----- Original Message -----

Sent: = Saturday, February 04, 2006 6:28 = PM

Subject: [FlyRotary] Re: Atkins errors

 

In a message dated 2/4/2006 = 5:56:30 PM Eastern = Standard Time, ALVentures@cox.net = writes:

A couple of questions: Why are two of the bolts larger?  What is the = torque spec on these bolts for the 20B?  I seem to recall 26-28 = ft-lbs.  I can’t get a torque wrench on the bolts without removing the = re-drive, engine mount and flywheel, but I have a pretty well calibrated = arm.

 

Al

When you add torque to those bolts, the bolts closest to them will go under = torque.

 

So go through the whole torque sequence several times if at all possible. This = has been the case on every engine I have built.

 

Lynn E. Hanover

 

 

 

I don't havea Mazda Manual, but generally in a case like this there are 2 ways to tighten the bolts = correctly:

 

a) Tighten 2 opposite bolts until seated - then torque each to spec. All = other bolts are tigthtened spreading out from the 2 torqued: =

e.g. Torque the 2 big bolts then: 1st bolt to left of one big b. - = 1st bolt to the left of the other big b. - 1st bolt to the right of = the one big b. - 1st bolt to the right of the other big b. - 2nd bolt to = the left...... you get the idea.

 

This way you have the pieces flat together on a "centerline" and "lay" the rest down on each side of this centerline - = spreading it out so that no "wrinkles" are created....

 

b) A stepped sequence is shown in a manual: mostly in cross pattern and = something like 10 lb/18lb/26lb

 

 

Thomas;

I understand the niceties of = torque sequence; but it would seem that is all out the window when the engine = has been run about 6 hours, many cycles to full power, and a dozen or more = temperature cycles to 200-210 F; all with the two large bolts loose.  As far as = I know nothing untoward has happened, but how can I be sure?

 

Al

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