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alum fuel line in front of firewall ok

rvator51

Well Known Member
I had to run a short alum fuel line from my firewall fitting to the gascolator. Is this ok or should I get a SS braided hose with insulation made up for this short run?

fuel-line.jpg
 
Neither. You should simply make the same line from stainless hardline. Unlike a hose assembly, it's light, cheap, and will last forever.
 
Fire and Vibration.

There are two main issues for FWF lines. Fire and vibration.

If the gascolator is firmly fixed then the pipe from the supply side can be alum but as Toobuilder says stainless would be more heat resistant. From the gascolator to the engine pump, and carb should be flexible, I use aeroqip 601 braided with fire sleeving.

Looks like a 4?
 
Neither. You should simply make the same line from stainless hardline. Unlike a hose assembly, it's light, cheap, and will last forever.

Based upon your photo Toolbuilder has the right solution - CRES tubing :) Aluminum fuel/oil lines (and AN fittings) inside the cowling is not a good practice.
 
Thanks guys,

Stainless rigid line it will be. Yes, it's wife's RV-4 that is getting a o-360to replace her run out O-320.
 
There's an alternative, to mount the gascolator against the firewall so that you can use a bulkhead fitting to connect the gascolator through the firewall.

This is how my Cessna 180 is.

Dave
 
One question, are you sure you want stainless steel? Isn't it more brittle than aluminum and thus more subject to cracking?

Regardless of the material you use, will want to insulate it.
 
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Stainless can certainly work harden, but brittle, no. This is the perfect application for this. Same stuff the prop governor and fuel pump to servo lines are made out of on many factory Lycomings.

We have a design engineer at work who says to "use stainless only when everything else will work"...

Translation: stainless is good stuff.
 
Stainless can certainly work harden, but brittle, no. This is the perfect application for this. Same stuff the prop governor and fuel pump to servo lines are made out of on many factory Lycomings.

We have a design engineer at work who says to "use stainless only when everything else will work"...

Translation: stainless is good stuff.

Thanks Mike!
 
Dont use a thin wall tube like, .020, .028. Yeah its easier to flare, and easier to crack. .035, .049 is better. Alittle harder to work with. Advantage is the tube wont wrinkle if you try to bend it too tight, and works well. Disadvantage is as the wall gets thicker, its harder to flare and most hand flaring tools wont handle it. .065 is TOUGH. My custom -6 hose ends are made from .065.
Tom
 
The End of the Story

Tom at TS Flightlines made me a SS line that fit perfect.
IMG_0613.JPG



He also made me all new fuel and oil lines. Great job!
IMG_0621.JPG
 
Looks great. With no relative movement, The pump to carb line would have been a fine candidate for a hardline too.
 
A hard line must be properly clamped to prevent vibration from cracking the line. For example lycoming has very specific instructions on clamping the prop gov and FI lines, the latter has a reoccuring AD against them for just this reason.

Personally I would have ditched that monstronsity of a gascolator, it serves almost no purpose on a low wing and acts as a huge heat sink for your fuel.
 
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Stainless Fuel Line

My firewall to gascolator fuel line is similar to the one made by Tom S. .035 SS but with steel nuts & sleeves rather than SS. Is this OK? The SS took a little more effort to flare but still came out nice & smooth - used oil to lube the flare die. Also fire sleeved the tube. Is this overkill?
 
Personally I would have ditched that monstronsity of a gascolator, it serves almost no purpose on a low wing and acts as a huge heat sink for your fuel.

Hi Walt,
Value your opinion. How would you ditch it? Just bypass it or put in a filter (what kind?) somewhere in line? The gascolator was in the plane when my wife bought it. When I first cleaned the gascolator, there was a lot of gunk and water in it so it did catch something. Since the first cleaning, I have seen nothing else. I am wondering what effect going from a O-320 to an O-360 and also moving the oil cooler from the front of the #2 cylinder to the back of the #4 cylinder is going to have on my cooling/potential for vapor lock. Will find out soon...
 
Hi Walt,
Value your opinion. How would you ditch it? Just bypass it or put in a filter (what kind?) somewhere in line? The gascolator was in the plane when my wife bought it. When I first cleaned the gascolator, there was a lot of gunk and water in it so it did catch something. Since the first cleaning, I have seen nothing else. I am wondering what effect going from a O-320 to an O-360 and also moving the oil cooler from the front of the #2 cylinder to the back of the #4 cylinder is going to have on my cooling/potential for vapor lock. Will find out soon...

Put an inline filter between the firewall and selector valve where its cool. I use a 70 micron FlowEzy 3000 unit, I can dig the number up if you need it.
 
Tom,

If you keep the gascolator (I would) put a light weight aluminum shield around it and feed that with a black plastic air tube from the back of the baffle. It has worked on our 8A for the last 11 years. Phoenix is hotter, but our field elevation exacerbates the vapor problem.

Jim Thornton
Durango
 
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