Gascolators and Fuel Lines

Submitted by Anonymous on

Forums: 

From: <rwolf99 [at] aol.com>
Sender: <marv [at] lancaironline.net>
Subject: Re: Gascolators and Fuel Lines
Date: Wed, 23 Jul 2014 10:47:41 -0400
To: <lml [at] lancaironline.net>

<<IMHO, if you don't know what type hose to use, maybe you shouldn't be making your own.>>
 
Awwww, c'mon now.  The list of what I didn't know when I started my Lancair was enormous.  That's why I asked questions, read lots of books, talked to a zillion vendors at Oshkosh, and read the LML almost every day.  Even the FAA says homebuilding is all about education!
 
I agree, if you don't know what type of hose to use, you shouldn't make your own until you find out!  Then, knock yourself out!  Although personally, I would have them professionally made *and pressure tested* rather than make my own.  Not that expensive and quite possibly better results on this critical component.
 
My answer -- use a Teflon-lined hose that is replaced "on condition" rather than at a fixed interval such as ten years.  Firesleeve them, too, at least the ones in the engine bay.  And finally, only use steel fittings unless the complete line does not move.  (i.e. if both ends are attached to firewall-mounted components, aluminum fittings are okay, although you should probably be using a hard line there.  If the hose attaches to the engine, that moves, so use a steel line.  Aluminum fittings could break in this scenario.)
 
- Rob Wolf
 

Gascolators and fuel lines

Submitted by Anonymous on

From: <dudewanarace [at] yahoo.com>
Sender: <marv [at] lancaironline.net>
Subject: Gascolators and fuel lines
Date: Wed, 23 Jul 2014 15:19:25 -0400
To: <lml [at] lancaironline.net>
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Undecoded Message
Mark,
Gascolator:
I have a gascolator installed on my fuel injected engine.  But, I suspect it is there because at one point the airplane was not fuel injected with the first engine. (Before I owned it)  That being said, I have never drained any water or debris out it before.  Actually it has been a bit of a pain with a leaking seal and one more sump drain to check / maintain.  If I were building I could see going without it and being just fine.

Fuel Lines:
I have replaced both fuel and oil lines on my firewall forward install.  Having been there, done that, I'll share my advice.

I would recommend using steel braided Teflon hose.  I get mine from Parker by the foot.  Get what you need, plus some.  I think this is the type of hose it is, but not positive.
 Don't have the part number handy..

While your there, buy the fittings you need.  Remember to tell them you need JIC fittings, not the stuff you find on a tractor, the angle is different.  Take a male AN fitting with you so they can measure it and be sure.  It helps to have the fittings to asses the
length you need and the bend radius out of the fitting.  The clamp area might be longer than you think.  I wrap the hose in masking tape before I cut it to keep the steel braid intact.  Once you have the host cut to length, I slip the firesleeve over the hose first, before the ends are clamped on.  This lets you use firesleeve that is one or two sizes smaller than normal because it doesn't fit over the fittings.  Makes for a smaller overall hose which comes in handy in our tight cowls.

Haul the stuff back to Parker and have them clamp the ends.  Keep in mind that if you are
using angled fittings, they need to be clocked accordingly.  If I use an angled fitting, I be sure to have a straight fitting on the other end.  Then you don't have to worry about keeping them clocked correctly.  By the way, I wouldn't mention the word "Airplane" at your local Parker store.  Just say Race Car, most of them use JIC fittings also.

I attached a couple pics of my new (and old) oil cooler lines I just replaced.  One shows the lines before the ends were clamped.  Sorry for the poor quality.. cell phone in the hanger, you know the deal.

Tom McNerney

Gascolators and fuel lines

Submitted by Anonymous on

From: Dennis Johnson <pinetownd [at] volcano.net>
Sender: <marv [at] lancaironline.net>
Subject: RE: Gascolators and fuel lines
Date: Thu, 24 Jul 2014 14:45:06 -0400
To: <lml [at] lancaironline.net>
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Undecoded Message
Adam suggested (as a thought experiment only!) pouring a cup of water into
a gas tank and then running the engine at high power to see what would
happen. 
 
To extend the thought experiment, takeoff power in my Legacy burns a gallon
of gasoline every two minutes, or 0.5 gallons per minute.  A cup of water,
if it somehow stayed together, would flush through the engine in about eight
seconds.  That's probably faster than I could react and switch fuel tanks,
turn the boost pump on, and set up for best glide. 
 
Of course, if that happened just as I cleared the departure end of the
runway, that could be a very long eight seconds.  The point is that at
takeoff power, a slug of water in a well maintained fuel system would flush
itself through the engine in seconds. 
 
I once owned a Caterpillar D2 bulldozer.  It had big capital letters
cast into the Diesel fuel cap that is good advice for us all:  "BUY
CLEAN FUEL.  KEEP FUEL CLEAN." 
 
Dennis
Legacy, 740 hours, no water detected in fuel sumps or gascolater so
far.