X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from an-out-0708.google.com ([209.85.132.245] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2134999 for flyrotary@lancaironline.net; Fri, 22 Jun 2007 22:08:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.132.245; envelope-from=rotary.thjakits@gmail.com Received: by an-out-0708.google.com with SMTP id b2so196800ana for ; Fri, 22 Jun 2007 19:08:02 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=JguXokauRpTQ6c3/pb/gbszYYhX65qulF6oHclTYxuQtE8r/iBUn4lFjF0WI4h7jgvZYhfHPPvo1vjZ6xADG74dK/kAVxGqa6KcRfr3ncIITPFFDIE0TUYX7xi1n4onFQc7mMTTHUqbhZD68bd4YTOjNxlMBm4r+r7Qx42BQ6Tg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=ZRzrHEuktMz3b7vcZmKe6AHXjkTHk7fJ4fg15NVG7d3IAxcx9joUvEuSHWSNRcD/dwS6jwRjSBwExjjpi6p94jzJxeMV4a0HmEUzc0IvwQKTf6buJhWfS/rfz4yYpm0mVqurzNI2pSesklY1kBfGIxwvG5/uE1IUj+jKC3CBVi0= Received: by 10.100.163.12 with SMTP id l12mr2029245ane.1182564482031; Fri, 22 Jun 2007 19:08:02 -0700 (PDT) Received: by 10.100.96.15 with HTTP; Fri, 22 Jun 2007 19:08:02 -0700 (PDT) Message-ID: <63163d560706221908g67bfb75dg928534c033bd4cbd@mail.gmail.com> Date: Fri, 22 Jun 2007 19:08:02 -0700 From: "Thomas Jakits" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] PP construction methods In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_170555_26641113.1182564482006" References: ------=_Part_170555_26641113.1182564482006 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline That would be a chance to try out the Alu-side housings WITHOUT any port... :) TJ On 6/20/07, cbeazley wrote: > > Greetings, > > One of the things that's always bothered me about making a PP housing is > leakage. I've heard very experienced folks say that eventually, any PP > housing you make will leak, and it's easy for me to imagine that happening. > I don't think I've heard the same thing about factory housings though. How > are the ports installed in the factory PP housing? > > The other problem with a conversion is the side ports. I know people fill > these with their favorite epoxy, but I'd worry about that coming loose, and > getting into the rotor. How much would it hurt the PP operation if you just > sealed the ports on the outside of the side housings with a plate where the > intake would have been? > > Cheers, > Rusty > > > Hi Rusty; > I have heard of several leaks with homemade PPport housings. Factory > housings are cast. > > I have read of several instances where epoxy filled sideports have > debonded and fallen into the engine ruining someone's day. > It only takes a few hours to make custom fit plugs. I grabbed some scrap > 1"? aluminum tube, bent to shape with a vice, cut and ground/sanded to fit. > Not perfect, but they will not fall into the engine. > > If you are really concerned about leaks you can fill the irons as Lynn > suggested. > You could also add another leak barrier layer of rubber or silicon with > different thermal expansion properties than the JB weld in the water > passage. > > BTW - JB Weld does not create the best surface bond to Aluminum without > some surface prep - try some on alclad. Etching works. You could also sand > the aluminum with epoxy on the surface to prevent the oxide surface from > forming. Another form of mechanical backup to prevent the tube insert from > falling in/out of the engine is probably not a bad idea - Welding, brazing, > threads, bolts, step, press fit... > > The hardest part is getting up the nerve to cut into a perfectly good > housing...practice on a junk housing first. > There are several threads at rx7club.com and nopistons.com > > Have fun! > Cary > > > ------=_Part_170555_26641113.1182564482006 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
That would be a chance to try out the Alu-side housings WITHOUT any port... :)
TJ

 
On 6/20/07, cbeazley <cbeazley@innovista.net> wrote:
Greetings,
 
One of the things that's always bothered me about making a PP housing is leakage.  I've heard very experienced folks say that eventually, any PP housing you make will leak, and it's easy for me to imagine that happening.  I don't think I've heard the same thing about factory housings though.  How are the ports installed in the factory PP housing? 
 
The other problem with a conversion is the side ports.  I know people fill these with their favorite epoxy, but I'd worry about that coming loose, and getting into the rotor.  How much would it hurt the PP operation if you just sealed the ports on the outside of the side housings with a plate where the intake would have been?  
 
Cheers,
Rusty
 
Hi Rusty;
I have heard of several leaks with homemade PPport housings.  Factory housings are cast.

I have read of several instances where epoxy filled sideports have debonded and fallen into the engine ruining someone's day.
It only takes a few hours to make custom fit plugs.  I grabbed some scrap 1"? aluminum tube, bent to shape with a vice, cut and ground/sanded to fit.
Not perfect, but they will not fall into the engine.

If you are really concerned about leaks you can fill the irons as Lynn suggested.
You could also add another leak barrier layer of rubber or silicon with different thermal expansion properties than the JB weld in the water passage.

BTW - JB Weld does not create the best surface bond to Aluminum without some surface prep - try some on alclad.  Etching works.  You could also sand the aluminum with epoxy on the surface to prevent the oxide surface from forming.  Another form of mechanical backup to prevent the tube insert from falling in/out of the engine is probably not a bad idea - Welding, brazing, threads, bolts, step, press fit...

The hardest part is getting up the nerve to cut into a perfectly good housing...practice on a junk housing first.
There are several threads at  rx7club.com and nopistons.com

Have fun!
Cary

 

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