X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail01.syd.optusnet.com.au ([211.29.132.182] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with ESMTPS id 2912752 for flyrotary@lancaironline.net; Wed, 07 May 2008 18:30:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.182; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-69-50.dsl.nsw.optusnet.com.au [220.236.69.50]) by mail01.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id m47MTcYQ025700 for ; Thu, 8 May 2008 08:29:39 +1000 Message-ID: <000c01c8b091$d8f23e80$6400a8c0@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Need ideas for bolts Date: Thu, 8 May 2008 08:29:42 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01C8B0E5.A9B4B1D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0009_01C8B0E5.A9B4B1D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Lynn, What are rod bolts? George (down under) ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Thursday, May 08, 2008 4:27 AM Subject: [FlyRotary] Re: Need ideas for bolts I would check on the torque required to get that bolt into its working = range. If it is over about 60 pounds, I would use a lower strength bolt = that can be torqued into its working range at 65 pounds or less. The = cast iron holes will not stand all that much in the way of torque. Its = kind of a fine thread unlike good old American engine blocks with big = diameter course threads.=20 Real SAE grade 5 bolts can be bent sharply over 90 degrees without = failing. Grade 8 bolts, while capable of a higher ultimate loading = (tensile) seldom make it to 90 degrees without failing. They are much = better in double shear than the grade 5 but this is not it. My driver = built up quite a store of data on this subject while going through a = half million dollars worth of bodywork. Even with grade 5 or whatever = that is in metric, torqued into their working range, you could pick the = plane up and shake it for 100 years by the reduction unit and no = fastener failures would occur.=20 Whenever we had a Cosworth apart we would change the rod bolts. They = were pricey but the owner wanted new bolts each time. I suspect that he = went past the red line every time he got into the car. The Cosworth rep = came to Mid Ohio once and found the owner. He wanted to know what we = were doing to the bolts that we needed so many. The rods were designed = around the bolts. Deep enough to get enough threads to get the bolt into = its working range. Then center to center distance and so on. He pointed = out that they could tear the big end off of the rod without failing the = cap or the bolts. So if the rod cap was still on the rod, it was fine. = So we quit changing rod bolts. They had dimples on each end and you = torque them with a special dial indicator rig in place, until they = stretch .0035" and that was it. Not by torque. By stretch. We never lost = a Cosworth engine. The bolt choice is limited by the cast iron holes. Perhaps studs for = some of the application.=20 Lynn E. Hanover In a message dated 5/7/2008 10:42:50 AM Pacific Daylight Time, = echristley@nc.rr.com writes: Where can I find extra long, high grade metric bolts that aren't=20 specialty order items? What other options do I have for securely bolting a plate to the = back of=20 the engine with 6" spacer? -------------------------------------------------------------------------= ----- Wondering what's for Dinner Tonight? Get new twists on family = favorites at AOL Food. -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG.=20 Version: 7.5.524 / Virus Database: 269.23.9/1416 - Release Date: = 5/05/2008 5:11 PM ------=_NextPart_000_0009_01C8B0E5.A9B4B1D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Lynn,
What are rod bolts?
George (down under)
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Thursday, May 08, 2008 = 4:27=20 AM
Subject: [FlyRotary] Re: Need = ideas for=20 bolts

I would check on the torque required to get that bolt into its = working=20 range. If it is over about 60 pounds, I would use a lower strength = bolt that=20 can be torqued into its working range at 65 pounds or less. The cast = iron=20 holes will not stand all that much in the way of torque. Its kind of a = fine=20 thread unlike good old American engine blocks with big diameter course = threads.
 
Real SAE grade 5 bolts can be bent sharply over 90 degrees = without=20 failing. Grade 8 bolts, while capable of a higher ultimate loading = (tensile)=20 seldom make it to 90 degrees without failing. They are much better in = double=20 shear than the grade 5 but this is not it. My driver built up quite a = store of=20 data on this subject while going through a half million dollars worth = of=20 bodywork. Even with grade 5 or whatever that is in metric, torqued = into their=20 working range, you could pick the plane up and shake it for 100 years = by the=20 reduction unit and no fastener failures would occur.
 
Whenever we had a Cosworth apart we would change the rod bolts. = They were=20 pricey but the owner wanted new bolts each time. I suspect that he = went past=20 the red line every time he got into the car. The Cosworth rep came to = Mid Ohio=20 once and found the owner. He wanted to know what we were doing to the = bolts=20 that we needed so many. The rods were designed around the bolts. Deep = enough=20 to get enough threads to get the bolt into its working range. Then = center to=20 center distance and so on. He pointed out that they could tear the big = end off=20 of the rod without failing the cap or the bolts. So if the rod cap was = still=20 on the rod, it was fine. So we quit changing rod bolts. They had = dimples on=20 each end and you torque them with a special dial indicator rig in = place, until=20 they stretch .0035" and that was it. Not by torque. By stretch. We = never lost=20 a Cosworth engine.
 
The bolt choice is limited by the cast iron holes. Perhaps studs = for some=20 of the application.
 
Lynn E. Hanover
 
 
 
 
In a message dated 5/7/2008 10:42:50 AM Pacific Daylight Time,=20 echristley@nc.rr.com writes:
Where can I find extra long, high grade metric bolts = that aren't=20
specialty order items?
What other options do I have for = securely=20 bolting a plate to the back of
the engine with 6"=20 spacer?



Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL = Food.

No virus found in this incoming message.
Checked by AVG.=20
Version: 7.5.524 / Virus Database: 269.23.9/1416 - Release Date: = 5/05/2008=20 5:11 PM
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