X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-ma06.mx.aol.com ([64.12.78.142] verified) by logan.com (CommuniGate Pro SMTP 5.4c2) with ESMTP id 4906073 for flyrotary@lancaironline.net; Mon, 14 Mar 2011 12:02:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.78.142; envelope-from=wrjjrs@aol.com Received: from mtaomg-da02.r1000.mx.aol.com (mtaomg-da02.r1000.mx.aol.com [172.29.51.138]) by imr-ma06.mx.aol.com (8.14.1/8.14.1) with ESMTP id p2EG1fOu015014 for ; Mon, 14 Mar 2011 12:01:41 -0400 Received: from core-dge003a.r1000.mail.aol.com (core-dge003.r1000.mail.aol.com [172.29.230.9]) by mtaomg-da02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 933A7E000096 for ; Mon, 14 Mar 2011 12:01:41 -0400 (EDT) References: To: flyrotary@lancaironline.net Content-Transfer-Encoding: quoted-printable Subject: Re: [FlyRotary] Re: Cracking exhaust manifolds/ Crankcase ventilation X-AOL-IP: 66.253.96.220 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: wrjjrs@aol.com X-MB-Message-Type: User Content-Type: text/plain; charset="utf-8"; format=flowed X-Mailer: AOL Webmail 33356-STANDARD Received: from 66.253.96.220 by angweb-usd004.sysops.aol.com (205.188.92.199) with HTTP (WebMailUI); Mon, 14 Mar 2011 12:01:41 -0400 Message-Id: <8CDB0783DF95B84-1504-517E@angweb-usd004.sysops.aol.com> X-Originating-IP: [66.253.96.220] Date: Mon, 14 Mar 2011 12:01:41 -0400 (EDT) x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:459889664:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338a4d7e3be5045d Lynn, Do you mean Belleville washers? Good idea but they may lose their=20 spring after a few heat cycles. Bill Jepson -----Original Message----- From: Mark Steitle To: Rotary motors in aircraft Sent: Sun, Mar 13, 2011 5:44 pm Subject: [FlyRotary] Re: Cracking exhaust manifolds/ Crankcase=20 ventilation Bevel washers... yes! =C2=A0That would work even better. =C2=A0Thanks for t= he=20 suggestion Lynn. =C2=A0 Mark On Sun, Mar 13, 2011 at 6:47 PM, wrote: In a message dated 3/13/2011 6:56:23 P.M. Eastern Daylight Time,=20 fluffysheap@gmail.com writes: =C2=A0On my home spun exhaust for my 3-rotor, I tighten the exhaust studs= =20 for the center rotor, but only snug down the bolts for #1 and #3 in=20 order to allow the exhaust manifold to grow and shrink as necessary.=20 =C2=A0With 1600-1700* EGT's, it seems obvious that the manifold will grow= =20 more than the engine and if not allowed to move, it will crack. =C2=A0By=20 torquing them only enough to prevent leakage, they are allowed to grow=20 as needed, preventing cracks. =C2=A0So far, no broken studs or cracked=20 exhaust manifold on my 3-rotor. =C2=A0 Mark S. =C2=A0 Bingo. =C2=A0 How about you torque up the center most stud to auto spec, then use 2=20 bevel washers flange to flange pulled down just short of flat on all=20 other studs. =C2=A0 Then use a short stack of bevel washers above and below a flange on the=20 turbo setup to a strut to support the weight and keep the strain off of=20 the manifold. =C2=A0 Lynn E. Hanover =C2=A0