X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail.lincsatmail.com ([207.179.143.254] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 970980 for flyrotary@lancaironline.net; Sun, 05 Feb 2006 12:38:58 -0500 Received-SPF: neutral receiver=logan.com; client-ip=207.179.143.254; envelope-from=echolakeresort@telus.net Received: from echolake-cc8a26 ([204.101.233.153]) (authenticated bits=0) by mail.lincsatmail.com (8.12.10/8.12.10) with ESMTP id k15HbrZj017065 for ; Sun, 5 Feb 2006 13:37:57 -0400 MIME-Version: 1.0 Message-Id: <43E637E8.000004.04024@ECHOLAKE-CC8A26> Date: Sun, 5 Feb 2006 09:37:44 -0800 (Pacific Standard Time) Content-Type: Multipart/Alternative; boundary="------------Boundary-00=_WA68BHK0000000000000" X-Mailer: IncrediMail (4502089) From: "Echo Lake Fishing Resort (Georges Boucher)" References: To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Torque and torque sequence X-FID: FLAVOR00-NONE-0000-0000-000000000000 X-Priority: 3 --------------Boundary-00=_WA68BHK0000000000000 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable FWIW backing off each bolt as you re-torque gives you a more accurate torque. Final torque is much more accurate when using the torque by rotation degree (bolt stretch). (never had to re-torque anything using t= he stretch system)=0D Georges B.=0D =0D -------Original Message-------=0D =0D From: rijakits=0D Date: 02/05/06 09:19:12=0D To: Rotary motors in aircraft=0D Subject: [FlyRotary] Re: Torque and torque sequence=0D =0D =0D ----- Original Message ----- =0D From: Al Gietzen =0D To: Rotary motors in aircraft =0D Sent: Sunday, February 05, 2006 11:32 AM=0D Subject: [FlyRotary] Torque and torque sequence=0D =0D =0D ----- Original Message ----- =0D From: Lehanover@aol.com =0D To: Rotary motors in aircraft =0D Sent: Saturday, February 04, 2006 6:28 PM=0D Subject: [FlyRotary] Re: Atkins errors=0D =0D In a message dated 2/4/2006 5:56:30 PM Eastern Standard Time, ALVentures@= cox net writes:=0D A couple of questions: Why are two of the bolts larger? What is the torq= ue spec on these bolts for the 20B? I seem to recall 26-28 ft-lbs. I can=92= t get a torque wrench on the bolts without removing the re-drive, engine mo= unt and flywheel, but I have a pretty well calibrated arm.=0D =0D Al=0D When you add torque to those bolts, the bolts closest to them will go und= er torque.=0D =0D So go through the whole torque sequence several times if at all possible. This has been the case on every engine I have built.=0D =0D Lynn E. Hanover=0D =0D =0D =0D I don't havea Mazda Manual, but generally in a case like this there are 2 ways to tighten the bolts correctly:=0D =0D a) Tighten 2 opposite bolts until seated - then torque each to spec. All other bolts are tigthtened spreading out from the 2 torqued: =0D e.g. Torque the 2 big bolts then: 1st bolt to left of one big b. - 1st bo= lt 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...... yo= u get the idea.=0D =0D This way you have the pieces flat together on a "centerline" and "lay" th= e rest down on each side of this centerline - spreading it out so that no=20 wrinkles" are created....=0D =0D b) A stepped sequence is shown in a manual: mostly in cross pattern and something like 10 lb/18lb/26lb=0D =0D =0D Thomas;=0D I understand the niceties of torque sequence; but it would seem that is a= ll 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 happene= d, but how can I be sure?=0D =0D Al=0D =0D Al, =0D didn't intend to step on your engineering prowess, you are waaaay ahead o= f me in that department! =0D Just was pointing out what (little) I remember from Engineering school.=0D 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.=0D In a (race)car you might get away with an "emergency"-thighten-up, but it= is your a** up in the air!!=0D Your engine was running well for a while now, so a complete tear-down see= ms 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. =0D I understand that it is definitely NOT your fault, but your engine builde= rs - you might believe these guys put a little more extra care into assembli= ng an AC engine - manual on the job, step by step list to hook off items, after-assembly check list, etc.=0D =0D 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 on= e cared enough to check torque, let alone sequence.=0D Doesn't shine to well on a supposedly reputable shop....=0D =0D Enough ranting, back lurking!=0D =0D Thomas J.=0D =0D =0D =20 --------------Boundary-00=_WA68BHK0000000000000 Content-Type: Text/HTML; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 FWIW backing off each bolt as you re-torque gives you a more a= ccurate torque. Final torque is much more accurate when using  the t= orque by rotation  degree (bolt stretch). (never had to re-torque an= ything using the stretch system)
Georges B.
 
-------Original Message-------
 
From: rijakits
Date: 02/05/06 09:= 19:12
Subject: [FlyRotar= y] Re: Torque and torque sequence
 
 
----- Original Message -----
<= B>From: Al Gietzen
Sent: Sunday, February 05, 2006 11= :32 AM
Subject: [FlyRotary] Torque and to= rque sequence

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

Sent: S= aturday, February 04, 20066:28 PM=

Subject: [FlyRotary] Re: Atkins errors

 

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

A couple of questions: Why are two of the bolts large= r?  What is the torque spec on these bolts for the 20B?  I seem= to recall 26-28 ft-lbs.  I can=92t get a torque wrench on the bolts= without removing the re-drive, engine mount and flywheel, but I have a p= retty 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 ea= ch to spec. All other bolts are tigthtened spreading out from the 2 torqu= ed:

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 t= o the right of the one big b. - 1st bolt to the right of the ot= her big b. - 2nd bolt to the left...... you get the idea.

 

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

 

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

 

 

Thomas;

I understand th= e niceties of torque sequence; but it would seem that is all out the wind= ow 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 la= rge bolts loose.  As far as I know nothing untoward has happened, bu= t how can I be sure?

&= nbsp;

Al

&= nbsp;

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 sc= hool.

In your case, the only acceptable (...for me) way to go is, to rem= ove the redrive, loosen all bolts and tighten them according to the manua= l.

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-d= own seems excessive, but I believe wrong ( or none ...) torque-settings w= ill 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 int= o 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. "N= iceties of torque sequence" applies IF DONE (right) - obviously on your e= ngine 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.

&= nbsp;

 

 
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