X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "Marc Wiese cardmarc@charter.net" Received: from pmg.Logan.com ([207.170.160.161] verified) by logan.com (CommuniGate Pro SMTP 6.4.0) with ESMTPS id 3784706 for flyrotary@lancaironline.net; Sat, 11 Jan 2025 11:43:13 -0500 Received: from pmg.Logan.com (localhost [127.0.0.1]) by pmg.Logan.com (Proxmox) with ESMTP id 5066E320DC for ; Sat, 11 Jan 2025 11:43:13 -0500 (EST) Received-SPF: pass (charter.net: 47.43.20.25 is authorized to use 'cardmarc@charter.net' in 'mfrom' identity (mechanism 'ip4:47.43.20.0/24' matched)) receiver=pmg.Logan.com; identity=mailfrom; envelope-from="cardmarc@charter.net"; helo=impout001.msg.chrl.nc.charter.net; client-ip=47.43.20.25 Received: from impout001.msg.chrl.nc.charter.net (impout001aa.msg.chrl.nc.charter.net [47.43.20.25]) by pmg.Logan.com (Proxmox) with ESMTPS for ; Sat, 11 Jan 2025 11:43:12 -0500 (EST) Received: from smtpclient.apple ([166.199.245.129]) by cmsmtp with ESMTPA id WeZktqJFbdjZlWeZltFWtI; Sat, 11 Jan 2025 16:43:06 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=charter.net; s=c20240129; t=1736613786; bh=7HTdCjZzY9BS+UfMMzHIxFaM/moMRYiiQHQLGAeWztg=; h=From:Subject:Date:References:In-Reply-To:To; b=mHsZ48C159TcoH8pAva63HGVC1GGxRevO/rOoRZWn5HTZDOyLov06bPlOTmC08vtg 7G7HJoYdmMhDgejvJtEBp45iuiTGWHli9GCgjd2zOSDVPYeUuxWWa7uTbC7KPenGtG P7UGx5ihQLieuIogNwo6SJfaWNcLCFFBOPAQBjyBN2WIfyX3XGguEQvs9kYpZDrI8z 6Enbqa8sE1Lv2fc+9bdbA3KDU/iaduOkUTSNNnWy2gYr6wroyTSgsqJZBXJqZcfIV1 X6lsF/J5yKZibJFGYFyZXn3hIqgJ4MUG1ZiIFlPhABARvtHLeSKSFaIWORHhRGEaV9 C/jZ55Kk1RH9g== Authentication-Results: charter.net; auth=pass (PLAIN) smtp.auth=cardmarc@charter.net X-Authority-Analysis: v=2.4 cv=O7c/vg9W c=1 sm=1 tr=0 ts=67829f9a a=71uCfIv87o+WYmBiHY6iHQ==:117 a=71uCfIv87o+WYmBiHY6iHQ==:17 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=eRLigfuSAAAA:8 a=hOpmn2quAAAA:8 a=7g1VtSJxAAAA:8 a=C_IRinGWAAAA:8 a=LKx0M-H_R4UbKbmOiTYA:9 a=MVfqLLHTWKkXy-go:21 a=_W_S_7VecoQA:10 a=lqcHg5cX4UMA:10 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=Urk15JJjZg1Xo0ryW_k8:22 a=BfhXYjFvZD4iae-mNffo:22 a=grOzbf7U_OpcSX4AJOnl:22 Content-Type: multipart/alternative; boundary=Apple-Mail-4A870D4A-9349-4513-BC5B-DAA43E485286 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) Subject: Re: [FlyRotary] Re: Flexplate cracks Date: Sat, 11 Jan 2025 10:42:54 -0600 Message-Id: <2111218B-DFBE-410F-A7E7-DA8E14A6D98E@charter.net> References: In-Reply-To: To: flyrotary@lancaironline.net X-Mailer: iPhone Mail (22B91) X-CMAE-Envelope: MS4xfCIc6/XUuOqpF8EoYiBKnsSrLl2yIQt/jP/QD7IEoBS3sJ2WkM6CRHvG08XZUPtQsP0SbOgY7My3WAaFhSiF7iEH+6RaMEPL7w4jrTyic3srE2pcV+tU vPmzoxRcT4T/KZjXE1gsOvhJ8JnatRgO9geomCLAmUtaY0URcxiJN4utnSmdeFFpAKnTU3kMiE6XHLIGxMfLqlcX0gpnAr8KRWQ= X-SPAM-LEVEL: Spam detection results: 0 BAYES_00 -1.9 Bayes spam probability is 0 to 1% DKIM_SIGNED 0.1 Message has a DKIM or DK signature, not necessarily valid DKIM_VALID -0.1 Message has at least one valid DKIM or DK signature DKIM_VALID_AU -0.1 Message has a valid DKIM or DK signature from author's domain DKIM_VALID_EF -0.1 Message has a valid DKIM or DK signature from envelope-from domain DMARC_MISSING 0.1 Missing DMARC policy FREEMAIL_FROM 0.001 Sender email is commonly abused enduser mail provider HTML_MESSAGE 0.001 HTML included in message KAM_MXURI 1.5 URI begins with a mail exchange prefix, i.e. mx.[...] MIME_HTML_ONLY 0.1 Message only has text/html MIME parts MIME_QP_LONG_LINE 0.001 Quoted-printable line longer than 76 chars MPART_ALT_DIFF 0.79 HTML and text parts are different SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record WEIRD_PORT 0.001 Uses non-standard port number for HTTP --Apple-Mail-4A870D4A-9349-4513-BC5B-DAA43E485286 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable So these cracked flex plates are ONLY on AT= equipped cars? Wonder how the MT plates fare?
M
Sent from my iPhone

On Jan 11, 2025, at 10:38=E2=80=AFAM, David C= OOK hoursaway1@comcast.net <flyrotary@lancaironline.net> wrote:
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I personally rem= oved two eng. from the RX7's, heard them start and run, drove one, both had c= racks in flex plates. David
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On 01/10/2025 11:50 PM EST Charlie England ceengland7@gmail.com <flyr= otary@lancaironline.net> wrote:
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They do crack in the car, regardless.
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On Fri, Jan 10, 2025 at 10:36=E2=80=AFPM Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
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Hi there Dave=20
 
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I understood the torque converter was driven from the flex plate.&nbs= p;
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Can someone confirm how power is transferred from the Eccentric to th= e torque converter?
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Steve Izett
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On 11 Jan 2025, at 9:35=E2=80=AFam, David Leonard wdleonard@gmail.co= m <flyrotary@lancaironline.net> wrote:
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in the car, the flex plates are only used to carry the torque fro= m the starter and are not designed to transmit the output of the engine. in o= ur setups. We have adapted this flex plate to transmit the entire output of t= he engine which it apparently is not up to. =20
 
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I had my rd1-b seize up a bearing during a race at Reno which ma= y have been due to gyroscopic forces, but I think the flex plate issue just n= eeds to be fixed by replacing all the flex plates with proper flywheels.&nbs= p;
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Dave Leonard 
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On Fri, Jan 10, 2025, 1:45=E2=80=AFAM Le Roux Breytenbach = breytenbachleroux@gmail.com <flyrotary@lancaironline.net>= ; wrote:
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What i can rember was this also a topic on the late Paul L grou= p discussion.=20
Maybe Dave Leonard can chime in - think more that it was gyros= copic forces that craked the plates
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Maybe i can find the photos and topic in my old mails
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Sent from my iPhone=20
Le Roux Breytenbach 
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On 10 Jan 2025, at 08:13, Andrew Martin andrew@martinag.com= .au <flyrotary@lancaironline.net> wrote:

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Maybe some of the cracking flexplates are resulting from s= tarting issues, the starter motor can hammer the ring gear if not meshing co= rrectly or if engine misfires on start. may explain why so many flexplates c= ome pre-cracked from the wreckers.
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Andrew
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On Fri, 10 Jan 2025 at 11:32, Stephen Izett stephen.izet= t@gmail.com <flyrotary@lancaironline.net> wrote:
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Hi M

I was wondering the same thing.=20

What I discovered first of all was that flex plates ar= e designed to flex (funny that) and cracking is not limited to our setup.=20=
There are companies that specialise in stronger flex p= lates, particularly for modified and higher horsepower engines.

Since our engines are being used at a higher horsepowe= r per unit time and therefore higher stress (assumption) perhaps our setup c= ould be likened to race applications.
But then our hours of use would be significantly lower= (assumption) than an average vehicle, but perhaps not a race application.
Is the cracking we are seeing consistent with race app= lications? But they dont race automatics, do they?

So my take on this is that perhaps the flexing of the p= late in our setup is to some extent higher than OEM.

Our options seem to be:
1. Replacing the OEM flex plate with a stronger part. S= teve B being the latest going down that track and in his case also removing t= he rubber isolation in the process.
2. Connect direct to the eccentric shaft and therefore= taking the stress off the Flex Plate doing away with the damping mechanism w= hich Tracy did, and perhaps is still doing. Would be real nice to know.

Like M, I would appreciate hearing what others know or= are thinking or doing.

Steve Izett












> On 10 Jan 2025, at 2:15=E2=80=AFam, Marc Wiese car= dmarc@charter.net <flyrotary@lancaironline.net> wrote:
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> Has the cause of these cracks been uncovered, and= if so, what is the current thinking on it? An AL racing plate?
> M
> Sent from my iPhone
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>> On Jan 9, 2025, at 1:31=E2=80=AFAM, Steven W.= Boese SBoese@uwyo.edu <flyrotary@lancaironline.net> wrote:
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>> Steve,
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>> I didn=E2=80=99t see the cracks prior to disa= ssembly and doubt that they could have been seen on the counterweight side v= ery well -if at all- when assembled.
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>> I replaced the Flexplate with a steel flywhee= l about a year ago.  Since then, I replaced the four rubber dampers wit= h machined aluminum discs giving a solid connection and then dynamically bal= anced the system.  This was done because maintaining a dynamic balance w= asn=E2=80=99t possible with the dampers.  Only a few hours of flight ha= ve occurred in this configuration so far and there has been no indication of= problems resulting from this change.
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>> Steve Boese
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>>> On Jan 8, 2025, at 11:03=E2=80=AFPM, Step= hen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net= > wrote:
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>>> =E2=97=86 This message was sent from a no= n-UWYO address. Please exercise caution when clicking links or opening attac= hments from external sources.
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>>> Hi Steve
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>>> Is this recent then?
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>>> I=E2=80=99m not able to get to my aircraf= t at present to check my flex plate which has probably seen 50 hours of serv= ice.
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>>> Was it possible to see these cracks assem= bled?
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>>> I would appreciate your reflections on Tr= acys latter choice to remove the damper, and particularly when using a timbe= r/glass prop such as an MT.
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>>> It would be great to have an update and c= urrent info from Tracy regarding his no damper hours if anyone can contact h= im.
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>>> Very helpful, thanks again Steve
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>>> Steve
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>> --
>> Homepage:  http://www.flyrotary.com/
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