Mailing List flyrotary@lancaironline.net Message #42929
From: Michael Silvius <silvius@gwi.net>
Subject: Re: [FlyRotary] Site gage tube tore like wet cardboard, YIKES
Date: Wed, 21 May 2008 09:39:20 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
A few more options:
 
Bing alcohol reistant fuel line (not sure if it is translucent)
 
 
Polyurethane tubing
(though in the web page it is not listed as such in the paper catalog it is listed as"unafected by fuels and oils")
 
more polyurethane fuel line
 
 
Tygon F-4040-A tube
 
Michael in Maine
 
 
 
----- Original Message -----
Sent: Tuesday, May 20, 2008 5:53 PM
Subject: [FlyRotary] Site gage tube tore like wet cardboard, YIKES

This may be one of these "known issues" that I was just clueless about, but a couple of weeks ago I arrived at the hangar to the strong smell of fuel in the air.  Uh oh.  I went to the plane and found about a 1/4 inch of fuel in the fuselage.  What gives?  I had just removed the old engine (13b) to build a new one when I found coolant in the rotor housings.  I thought that perhaps moving the fuel lines around behind the firewall may have allowed fuel to flow in a wired way and it drained into the cabin.....not sure, but first things first, lets clean the fuel up......anyone got a cigarette???? <g>
 
After all was clean  and no more fuel was leaking I put the issue on the back burner to think about it and to check all the lines.  I am waiting for the PSRU to come back from Tracy so I am doing some major "clean up" of "proof of concept" wire runs etc. 
 
As I was re-running the wire that goes to the strake (Velocity SE) fuel sender I had to move the wire around the "clear" tubing that is used as a site gage in the strake luggage area.  To my shock the tubing ripped with just a slight touch.  In my dismay I pressed it with my fingernail and my nail cut clean through it.  I looked and found a crack on the pilot side tubing.  Hmmmmmm, since I checked all my aluminum connections inside the cabin and all were secure and, the sump was still full of fuel I am guessin' I found my fuel leak.
 
Is this common?  What did I do wrong?  My first thought is this clear tubing is NOT compatible with auto gas. I have been fuel with local auto gas from the local station.  I don't remember but it MAY have some ethanol included.  I do not have much concerns there is issue with the tanks themselves as they were coated with Jeffco way back when.
 
What tubing would y'all recommend for this use, that is clear AND not subject to deteriorating?  Really, it tore like wet cardboard.  I must have completely missed earlier discussion on this problem.  But, alas, would much rather find it now.  I got some regular black fuel lines to use until I find a solution so I can continue my engine development as my PSRU arrived back today.
 
Thanks all.
 
All the best,
 
Chris
Houston
 
Velocity SE/FG w/ rotary 13b
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