X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.2 cv=HLeBLclv c=1 sm=1 tr=0 a=Okj+Y/YBQJuJnTeIWgm92A==:117 a=29enrAnRItQSTk1fLlBiTQ==:17 a=7oIiURvLaKEA:10 a=17xQtuQ_ucwA:10 a=x7bEGLp0ZPQA:10 a=Fee85h93u3AA:10 a=R9QF1RCXAYgA:10 a=Ia-xEzejAAAA:8 a=7g1VtSJxAAAA:8 a=Pt_t0UP693MQbSA1PYsA:9 a=gg6weYfmO7f4He_l:21 a=UgbMP-RmtyxVukox:21 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=VJLYuiMj74kJqJRQ:21 a=7wCQZ153LFnhyLC2:21 a=fgBZ5Mi7bUt8WXPQ:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Accountlehanover lehanover@aol.com" Received: from omr-m007e.mx.aol.com ([204.29.186.9] verified) by logan.com (CommuniGate Pro SMTP 6.2.5) with ESMTPS id 11336763 for flyrotary@lancaironline.net; Wed, 04 Jul 2018 18:48:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=204.29.186.9; envelope-from=lehanover@aol.com Received: from mtaomg-mba02.mx.aol.com (mtaomg-mba02.mx.aol.com [172.26.133.112]) by omr-m007e.mx.aol.com (Outbound Mail Relay) with ESMTP id A4EE03800085 for ; Wed, 4 Jul 2018 18:48:12 -0400 (EDT) Received: from core-mdd01e.mail.aol.com (core-mdd01.mail.aol.com [172.27.62.11]) by mtaomg-mba02.mx.aol.com (OMAG/Core Interface) with ESMTP id 6458638000082 for ; Wed, 4 Jul 2018 18:48:12 -0400 (EDT) Received: from 71.67.186.114 by webjas-vae153.srv.aolmail.net (10.96.23.156) with HTTP (WebMailUI); Wed, 04 Jul 2018 18:48:11 -0400 Date: Wed, 4 Jul 2018 18:48:12 -0400 To: flyrotary@lancaironline.net Message-Id: <164677b4d33-c8e-9913@webjas-vae153.srv.aolmail.net> In-Reply-To: References: Subject: Re: [FlyRotary] Re: [flyrotary ] RE: Tension Bolts MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_51255_380267882.1530744491315" X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS DWEB X-Originating-IP: [71.67.186.114] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1530744492; bh=tZUMJhJF89ICH3YwXUl/Ep35084FWED//Ztk68NUaxA=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=Pw+0AUc9YrJXC8eeSsgKXC4SdRfYiKkD/+a2uccjO+WxuMJjmiMBdgnYxh9+V9848 Tn59Ei/KEskkl118xQN+76OuH/Hv+qI3StsHO13nttdfwTAfSvzzfBeSRlFGnwJeP3 +JHCZJaijJjbtHzgHiQxJm9sKAAyvzvH58+qreV0= x-aol-sid: 3039ac1a85705b3d4eac6e92 ------=_Part_51255_380267882.1530744491315 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Tension bolt failures are rare when operating below 8,000 RPM. This is caus= ed by the bolt ringing, or being sympathetic to major frequencies produced = by the engine. Early engines were mounted by the front cover and the next s= upport was the transmission mount. So a big bending load was always in play= .=C2=A0 Under shock loading such as a dropped clutch, the engine twists aga= inst the dowels and this is resisted by only the front cover. Later engines= were supported by mounts bolted to the center iron. This helped with failu= res of broken dowels in very high output engines. Later engines were suppor= ted only by the rear iron for the same reason. Some early engines would bre= ak a chunk out of the rear iron dowel hole. These were drag racing engines = at high power settings being shifted with dog ring transmissions that produ= ce brutal shock loads.=C2=A0 =C2=A0So, builders started adding more dowels.= Works well up to big HP. Then add turbocharging and more broken dowels. Th= en add more dowels and, or, add oversized bolts. or studs. The stack has to= be assembled and holes reamed to be a tight fit on the bolts. Holes drille= d out and re threaded. And stupid high torque on the bigger bolts. The next= step was to increase the size of the oil pan bolt holes, and then add a th= ick plate to the engine with a hole in the center under the center iron dra= in back hole. Bolt the pan to that or just run a dry sump and the plate wou= ld have no through hole at all.=C2=A0 Airplane engines probably will never = make enough torque to have these problems. =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Later engines came with a sort of rubber hose m= olded around the center of each bolt which cured the problem. Or you can ad= d a spiral of silicone (GE 100% pure) tub and tile caulk, the full length o= f the bolt. Let it gel up for a few minutes before inserting the bolt. The = effect is that you sort of glue the bolt to the engine so it cannot ring. I= t makes a giant mess but it is cheap. I only had two bolts break in 30 year= s. Later bolts are not necked down. I never lost one of those. I never used= Mocal coolers so I cannot comment.=C2=A0=C2=A0 =C2=A0 Lynn E. Hanover =C2=A0 In a message dated 7/4/2018 7:49:44 AM Eastern Standard Time, flyrotary@lan= caironline.net writes: =C2=A0 My aluminum plate is 0.5" thick; you can see it is routed around the rubbe= r mounts, the center is wide open - just a 2.5"-3"" strip of metal left aro= und the oil pan bolts/engine mating surface. Jeff -----Original Message----- Out of curiosity (of course otherwise why would i ask) what is the thicknes= s of your plate between the pan and the engine? Happy 4th Rich -----Original Message----- From: Jeff Whaley=20 Sent: July-03-18 10:41 AM To: 'Rotary motors in aircraft' Subject: RE: [flyrotary ] RE: Tension Bolts Rich, my engine is a 1988 13B, normally aspirated, aluminum plate bed mount= , so the engine is held in-place by the oil pan bolts. The aluminum plate a= nd engine mount are of my own design and construction. Jeff -----Original Message----- Thanks Jeff Which model of rotary What kind of engine mount Any other modifications to the engine Rich -----Original Message----- From: Jeff Whaley=20 Sent: July-03-18 9:54 AM To: Rotary motors in aircraft Subject: RE: [flyrotary ] RE: Tension Bolts FWIW: I had one broken tension bolt on spark plug side of the engine; not e= xactly sure which one but it was around the 10 o'clock position if looking = at the bolt heads end. The bolt broke in the threaded portion right where t= he threads were no longer engaged with the housing ... this was posted way = back in 2011 ... see message #53485. Jeff -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.ht= ml ------=_Part_51255_380267882.1530744491315 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Tension bolt failures are = rare when operating below 8,000 RPM. This is caused by the bolt ringing, or= being sympathetic to major frequencies produced by the engine. Early engin= es were mounted by the front cover and the next support was the transmissio= n mount. So a big bending load was always in play.  Under shock loadin= g such as a dropped clutch, the engine twists against the dowels and this i= s resisted by only the front cover. Later engines were supported by mounts = bolted to the center iron. This helped with failures of broken dowels in ve= ry high output engines. Later engines were supported only by the rear iron = for the same reason. Some early engines would break a chunk out of the rear= iron dowel hole. These were drag racing engines at high power settings bei= ng shifted with dog ring transmissions that produce brutal shock loads.&nbs= p;  So, builders started adding more dowels. Works well up to big HP. = Then add turbocharging and more broken dowels. Then add more dowels and, or= , add oversized bolts. or studs. The stack has to be assembled and holes re= amed to be a tight fit on the bolts. Holes drilled out and re threaded. And= stupid high torque on the bigger bolts. The next step was to increase the = size of the oil pan bolt holes, and then add a thick plate to the engine wi= th a hole in the center under the center iron drain back hole. Bolt the pan= to that or just run a dry sump and the plate would have no through hole at= all.  Airplane engines probably will never make enough torque to have= these problems.

      &nbs= p;Later engines came with a sort of rubber hose molded around the center of= each bolt which cured the problem. Or you can add a spiral of silicone (GE= 100% pure) tub and tile caulk, the full length of the bolt. Let it gel up = for a few minutes before inserting the bolt. The effect is that you sort of= glue the bolt to the engine so it cannot ring. It makes a giant mess but i= t is cheap. I only had two bolts break in 30 years. Later bolts are not nec= ked down. I never lost one of those. I never used Mocal coolers so I cannot= comment. 

Lynn E. Hanover

In a message dated 7/4/2018 7:49:44 AM Eastern Standard Time, flyrotary@lan= caironline.net writes:

My aluminum plate is 0.5" thick; yo= u can see it is routed around the rubber mounts, the center is wide open - = just a 2.5"-3"" strip of metal left around the oil pan bolts/engine mating = surface.
Jeff

-----Original Message-----
Out of curio= sity (of course otherwise why would i ask) what is the thickness of your pl= ate between the pan and the engine?

Happy 4th

Rich
-----Original Message-----
From: Jeff Whaley
Sent: July= -03-18 10:41 AM
To: 'Rotary motors in aircraft'
Subject: RE: [fly= rotary ] RE: Tension Bolts

Rich, my engine is a 1988 13B, normal= ly aspirated, aluminum plate bed mount, so the engine is held in-place by t= he oil pan bolts. The aluminum plate and engine mount are of my own design = and construction.
Jeff


-----Original Message-----
Thanks Jeff

Which model of rotary

What kind of engi= ne mount

Any other modifications to the engine

Rich
-----Original Message-----
From: Jeff Whaley
Sent: Jul= y-03-18 9:54 AM
To: Rotary motors in aircraft
Subject: RE: [flyro= tary ] RE: Tension Bolts

FWIW: I had one broken tension bolt on = spark plug side of the engine; not exactly sure which one but it was around= the 10 o'clock position if looking at the bolt heads end. The bolt broke i= n the threaded portion right where the threads were no longer engaged with = the housing ... this was posted way back in 2011 ... see message #53485. Je= ff



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