X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 25 Nov 2013 08:09:03 -0500 Message-ID: X-Original-Return-Path: Received: from mail-qe0-f49.google.com ([209.85.128.49] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6612732 for lml@lancaironline.net; Mon, 25 Nov 2013 03:10:00 -0500 Received-SPF: none receiver=logan.com; client-ip=209.85.128.49; envelope-from=bob@bmackey.com Received: by mail-qe0-f49.google.com with SMTP id w7so3457739qeb.36 for ; Mon, 25 Nov 2013 00:09:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:date:message-id:subject:from :to:content-type; bh=qpJZE64dAsIcjWD1ZlvK/LEtJZe8MKu6ukPHiRp/BoU=; b=KzSBd9tii3S3VH7QaD8/5WehUeJ+1lMkJbhsBbhsxu2DzVViKi85c8NkLNsk0vOpZq 1evGNiLbqG+KLfGNGaGSH1jQAoy6JejnI5IbRpY+JE/fCPl75P5GPVtvHW5ZV4k8SFbd 8vnrw+CZGixQr0cu0+k+OVHW4bP1so732yn5jv/1gvThdpjAAUkVBJ+mfc9xp1zbg12y ZkoFDrOZjf5KIOfueA1wDqU6gN+3S4T+tQnanhQjriADg2o1UrDjTfEI2kSYAZp1/g6B VcOumT0Pilij32On5SXRBOWRZK1f/h5qQxefyvxF47VV9lLW8LwDUXCOShNdOshi2MrH 5fBg== X-Gm-Message-State: ALoCoQkYxuxY04EGkJlLbeoRxIiQSo7JgZeAdXhHnFViK8/EcNZHEHrsyDwkZqYXpE3BgnyFZ25f MIME-Version: 1.0 X-Received: by 10.224.11.68 with SMTP id s4mr43660288qas.88.1385366965252; Mon, 25 Nov 2013 00:09:25 -0800 (PST) X-Original-Sender: bob@bmackey.com Received: by 10.96.79.225 with HTTP; Mon, 25 Nov 2013 00:09:25 -0800 (PST) X-Originating-IP: [108.72.124.238] X-Original-Date: Mon, 25 Nov 2013 00:09:25 -0800 X-Google-Sender-Auth: d0JfLZTRX4qHuTzuyrqqfqHEgCc X-Original-Message-ID: Subject: [LNC2] Lycoming Exhaust Flange Nuts From: bob mackey X-Original-To: lml@lancaironline.net Content-Type: multipart/alternative; boundary=001a11c2c370d9080004ebfbe1ec --001a11c2c370d9080004ebfbe1ec Content-Type: text/plain; charset=ISO-8859-1 John Cooper asks: Has anybody used 12 pt. reduced-dimension nuts on their exhaust flanges? I was surprised that they were even available with course threads, but >Summit Racing carries them in stainless steel with coarse threads (photo at link). I ordered 8 of these today which I intend to use on my exhaust flanges. They take a 3/8" wrench which I am confident will have enough clearance to be able to get back behind the exhaust pipe where a 1/2" wrench won't fit. These are *not *lock-nuts so I'll still use a split lock washer underneath. Any comments on this plan would be appreciated I also switched to 12-point reduced diameter "K-nuts" for my Lycoming exhaust. However, I would strongly advise against using stainless steel. It will gall and weld to the stud, then the stud will come out with the nut. If you're lucky. If not so lucky, the stud will break off. I used a black-oxide chrome-moly steel flange locknut from the aviation department at McMaster Carr. Part Number 90759A200 Chrome-Moly Alloy Steel 12-Point Flange Nut, Black-Oxide, 5/16"-18 Thread Size http://www.mcmaster.com/#nuts/=pj23uv Before I switched to the 12-point nuts, I used a 1/4 drive socket ground down to fit into the space. the socket depth was cut down so that it just engaged the top 1/8" of the 1/2" hex nut. BTW "standard" 5/16-18 hex nuts fit a 1/2" wrench. If your nuts need a 9/16" wrench, they are "heavy" nuts. --001a11c2c370d9080004ebfbe1ec Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

John Cooper <snopercod@comporium.net> asks:=A0

Has anybody used 12= pt. reduced-dimension nuts on their exhaust flanges? I was surprised that they were even available with course threads, but <a href=3D"http://www.summitracing.com/parts/a= rp-401-8303/overview/">Summit Racing</a> carries them in stainless steel with coarse threads (photo at link). I ordered 8 of these today which I intend to use on my exhaust flanges. They take a 3/8" wrench which I am confident will have enough clearance to be able to get back behind the exhaust pipe where a 1/2" wrench won't fit. These are not lock-= nuts so I'll still use a split lock washer underneath. Any comments on this plan would be appreciated

I also switched to 12= -point reduced diameter "K-nuts" for my Lycoming exhaust.=A0

However, I would strongly advise against using stainless steel. It wi= ll gall and weld to the stud, then the stud will come out with the nut. If = you're lucky. If not so lucky, the stud will break off.=A0

I used a black-oxide chrome-moly steel flange locknut f= rom the aviation department at McMaster Carr.=A0

Part Number 90759A200

http://www.mcmaste= r.com/#nuts/=3Dpj23uv

Before I switched to= the 12-point nuts, I used a 1/4 drive socket ground down to fit into the s= pace. the socket depth was cut down so that it just engaged the top 1/8&quo= t; of the 1/2" hex nut.=A0

BTW "standard" 5/16-18 hex nuts fit a 1/2" wrench. If y= our nuts need a 9/16" wrench, they are "heavy" nuts.=A0

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