X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [201.225.225.168] (HELO cwpanama.net) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 970965 for flyrotary@lancaironline.net; Sun, 05 Feb 2006 12:19:10 -0500 Received-SPF: none receiver=logan.com; client-ip=201.225.225.168; envelope-from=rijakits@cwpanama.net Received: from [201.224.93.110] (HELO usuarioq3efog0) by frontend2.cwpanama.net (CommuniGate Pro SMTP 4.2.10) with SMTP id 58251797 for flyrotary@lancaironline.net; Sun, 05 Feb 2006 12:37:54 -0500 Message-ID: <002701c62a78$24af2ce0$6e5de0c9@usuarioq3efog0> From: "rijakits" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Torque and torque sequence Date: Sun, 5 Feb 2006 12:18:12 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0023_01C62A4E.3B98C080" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 This is a multi-part message in MIME format. ------=_NextPart_000_0023_01C62A4E.3B98C080 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit ----- Original Message ----- From: Al Gietzen To: Rotary motors in aircraft Sent: Sunday, February 05, 2006 11:32 AM Subject: [FlyRotary] Torque and torque sequence ----- Original Message ----- From: Lehanover@aol.com To: Rotary motors in aircraft 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 Al, didn't intend to step on your engineering prowess, you are waaaay ahead of me in that department! Just was pointing out what (little) I remember from Engineering school. In your case, the only acceptable (...for me) way to go is, to remove the redrive, loosen all bolts and tighten them according to the manual. In a (race)car you might get away with an "emergency"-thighten-up, but it is your a** up in the air!! Your engine was running well for a while now, so a complete tear-down seems excessive, but I believe wrong ( or none ...) torque-settings will show their ugly face in the long run. Better make sure everything is right and tight. I understand that it is definitely NOT your fault, but your engine builders - you might believe these guys put a little more extra care into assembling an AC engine - manual on the job, step by step list to hook off items, after-assembly check list, etc. In your case torques on bolts don't mean anything at this time. "Niceties of torque sequence" applies IF DONE (right) - obviously on your engine no one cared enough to check torque, let alone sequence. Doesn't shine to well on a supposedly reputable shop.... Enough ranting, back lurking! Thomas J. ------=_NextPart_000_0023_01C62A4E.3B98C080 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Sunday, February 05, 2006 = 11:32=20 AM
Subject: [FlyRotary] Torque and = torque=20 sequence

-----=20 Original Message -----

From: Lehanover@aol.com=20

To: Rotary motors in = aircraft=20

Sent:=20 Saturday, February=20 04, 2006=20 6:28=20 PM

Subject: = [FlyRotary] Re:=20 Atkins errors

 

In a = message dated=20 2/4/2006=20 5:56:30=20 PM Eastern = Standard=20 Time, ALVentures@cox.net=20 writes:

A = couple of=20 questions: Why are two of the bolts larger?  What is the = torque spec=20 on these bolts for the 20B?  I seem to recall 26-28 = ft-lbs.  I=20 can=92t get a torque wrench on the bolts without removing the = re-drive,=20 engine mount and flywheel, but I have a pretty well calibrated=20 arm.

 

Al

When=20 you add torque to those bolts, the bolts closest to them will go = under=20 torque.

 

So go=20 through the whole torque sequence several times if at all possible. = This has=20 been the case on every engine I have built.

 

Lynn=20 E. Hanover

 

 

 

I=20 don't havea Mazda Manual, but generally in a = case like=20 this there are 2 ways to tighten the bolts=20 correctly:

 

a)=20 Tighten 2 opposite bolts until seated - then torque each to spec. = All other=20 bolts are tigthtened spreading out from the 2 torqued:=20

e.g.=20 Torque the 2 big bolts then: 1st bolt to left of one big = b. - 1st=20 bolt to the left of the other big b. - 1st bolt to the right of = the one=20 big b. - 1st bolt to the right of the other big b. - 2nd bolt = to the=20 left...... you get the idea.

 

This=20 way you have the pieces flat together on a "centerline" and "lay" = the rest=20 down on each side of this centerline - spreading it out so that no=20 "wrinkles" are created....

 

b) A=20 stepped sequence is shown in a manual: mostly in cross pattern and = something=20 like 10 lb/18lb/26lb

 

 

Thomas;

I = understand the=20 niceties of torque sequence; but it would seem that is all out the = window=20 when the engine has been run about 6 hours, many cycles to full = power, and a=20 dozen or more temperature cycles to 200-210 F; all with the two = large bolts=20 loose.  As far as I know nothing untoward has happened, but how = can I=20 be sure?

 

Al

 

Al,

didn't intend to step on your engineering prowess, = you are=20 waaaay ahead of me in that department!

Just was pointing out what (little) I remember from=20 Engineering school.

In your case, the only acceptable (...for me) way to = go is, to=20 remove the redrive, loosen all bolts and tighten them according to = the=20 manual.

In a (race)car you might get away with an=20 "emergency"-thighten-up, but it is your a**  up in the=20 air!!

Your engine was running well for a while now, so a = complete=20 tear-down seems excessive, but I believe wrong ( or none ...)=20 torque-settings will show their ugly face in the long run. Better = make sure=20 everything is right and tight.

I understand that it is definitely NOT your fault, = but your=20 engine builders - you might believe these guys put a little more = extra care=20 into assembling an AC engine - manual on the job, step by step list = to hook=20 off items, after-assembly check list, etc.

 

In your case torques on bolts don't mean anything at = this=20 time. "Niceties of torque sequence" applies IF DONE (right) - = obviously on=20 your engine no one cared enough to check torque, let alone=20 sequence.

Doesn't shine to well on a supposedly reputable=20 shop....

 

Enough ranting, back = lurking!

 

Thomas J.

 

 

------=_NextPart_000_0023_01C62A4E.3B98C080--