Help on custom fuel lines
05-16-2006, 08:36 PM
#11
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05-16-2006, 09:04 PM
#13
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Re: Help on custom fuel lines
Ok RatMan, here is a fitting I made by cutting apart 3 fittings and welding together what I needed, it has a radius 90 which is the way to roll for fuel. It has a hose barb on one end. For this application I would cut that off and weld on a tube fitting. That would make it work nice!
Last edited by Comanche3Six; 08-29-2007 at 10:41 AM.
05-16-2006, 10:52 PM
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Re: Help on custom fuel lines
Not sure about this, but I think Coast Guard requires a hard steel, not copper or aluminum, line from the fuel pump to the carb.
If that is so, then using soft line would tend to void your insurance if there was a fire due to the line breaking and spraying fuel all over the engine, then ignition source= Boom.
Both copper and aluminum will fatigue and crack. Also, braided lines are not fire temperature resistant like the steel line is.
Flaring with double flaring tool is easy. Maybe a hydraulic shop will do it for you after you have the line bent to the correct shape.
My recollection is to debur the inside of the cut off tube, then clamp it in the die block for the flarer, but get a close grip on it so it doesn't bend over to one side when you run the forcing screw down. You may have to do the first step in two operations to get the inward cup started, then loosen the clamp dies and move it outward a little more, and do more of the inward cup. Then you can put in the cone to flare it out to 45 degrees.
I think 37 degree flares are ok on fuel and maybe even 45 degree external flares. Some flare nuts are longer than others and therefore provide a vibration restraining collar to provide extra support to the tube at the fitting.
Internal flares were developed by the auto industry so save the cost of installing a separate flare fitting into the body of the part in question. The factory has a special drill and tap and beveled end such that the whole thing is done right into the carb body or brake caliber. I don't like them much as they tend to get siezed and are a bear to get undone without ruining something.
If that is so, then using soft line would tend to void your insurance if there was a fire due to the line breaking and spraying fuel all over the engine, then ignition source= Boom.
Both copper and aluminum will fatigue and crack. Also, braided lines are not fire temperature resistant like the steel line is.
Flaring with double flaring tool is easy. Maybe a hydraulic shop will do it for you after you have the line bent to the correct shape.
My recollection is to debur the inside of the cut off tube, then clamp it in the die block for the flarer, but get a close grip on it so it doesn't bend over to one side when you run the forcing screw down. You may have to do the first step in two operations to get the inward cup started, then loosen the clamp dies and move it outward a little more, and do more of the inward cup. Then you can put in the cone to flare it out to 45 degrees.
I think 37 degree flares are ok on fuel and maybe even 45 degree external flares. Some flare nuts are longer than others and therefore provide a vibration restraining collar to provide extra support to the tube at the fitting.
Internal flares were developed by the auto industry so save the cost of installing a separate flare fitting into the body of the part in question. The factory has a special drill and tap and beveled end such that the whole thing is done right into the carb body or brake caliber. I don't like them much as they tend to get siezed and are a bear to get undone without ruining something.
05-16-2006, 11:21 PM
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Re: Help on custom fuel lines
According to the Gentleman that surveyed the SeaRay, the fuel line from the pump to the carb must have at least a A-1 rating, something like 1400 degrees for three minutes. Most AreoQuip hose are NOT Coast Gusrd approved, but that doesn't mean that they are NOT A-1 rated.
Robert
Robert
05-17-2006, 12:30 PM
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Re: Help on custom fuel lines
Hey thanks for all the advise! For now, I'm going to go with steel lines with the pre-fab internal flares. That will get me in the water anyway, and USCG approved. I would definately prefer stainless, but don't think I can bend it (and I KNOW I can't flare it). I think I'll make an extra one out of steel and look around for a shop to duplicate it for me in stainless over the winter. Regards!
05-18-2006, 10:40 AM
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Re: Help on custom fuel lines
tewks;
You can bend and double flare SS tubing as easily as doing steel. You may have to anneal the tube end after the cupping step, but you can polish it after the final flaring using very fine emery paper, sometimes called "crocus cloth". It is colored redish brown and very fine abrasive. Check with very extensive hardware stores and ask a man, not the cute girl behind the register.
Go to mcmaster.com and do some research on tube benders and flaring tools, and also check emery cloth/crocus cloth.
Jim in Texas
You can bend and double flare SS tubing as easily as doing steel. You may have to anneal the tube end after the cupping step, but you can polish it after the final flaring using very fine emery paper, sometimes called "crocus cloth". It is colored redish brown and very fine abrasive. Check with very extensive hardware stores and ask a man, not the cute girl behind the register.
Go to mcmaster.com and do some research on tube benders and flaring tools, and also check emery cloth/crocus cloth.
Jim in Texas
