flex fuel lines

Discussion in 'Intake Systems , fuel systems and related' started by grumpyvette, Dec 31, 2010.

  1. grumpyvette

    grumpyvette Administrator Staff Member

    http://www.hotrod.com/techarticles/engi ... index.html



    http://www.enginebasics.com/Advanced Engine Tuning/Fuel Line Sizing.html



    these sub links contain a great deal of related info so don,t skip them, yes I'm fully aware some of you would rather be skinned alive & rolled in salt and alcohol and set on fire rather than read links with info you need!

    http://www.duccutters.com/ConvertionCha ... bzyv5ytbP1



    http://www.youtube.com/watch?feature=pl ... uIoAa5RRBs







    Performance Fuel Hoses - When Good Hoses Go Bad
    Aggressive Fuel Additives And New Lightweight Materials Technology Are Radically Changing The Performance Fuel Hose Market. Here's What You Need To Know.
    From the January, 2011 issue of Hot Rod
    By Marlan Davis
    Photography by The Manufacturer, Marlan Davis

    Performance Fuel Hoses Rubber Hose
    That old rubber hose, it ain't...

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    Performance Fuel Hoses Rubber Hose
    That old rubber hose, it ain't what it used to be. Today's aggressive fuel additives have greatly shortened the life span of traditional rubber-based hoses.
    The performance and racing fuel-hose market is on the verge of its biggest transformation in the last 50 years. Ever since the '60s, when aircraft-derived, rubber-core, stainless steel-braided hose and the familiar red-and-blue aluminum fittings began to replace parts store black rubber hose and worm-drive clamps as the performance and racing fuel hose of choice, the hot rod fuel-hose market has been relatively stable. True, the hose and fittings have evolved incrementally, with different manufacturers featuring their own pet design innovations, but until recently, the basic appearance and system functionality have stayed pretty much the same. And now that's become a problem: Similar to the flat-tappet cam failure problem HOT ROD reported on a few years back, a perfect storm of diverse factors have combined that under certain conditions may seriously degrade the reliability and safety of traditional rubber-based hose formulations when used over extended time periods.
    Cooler fuel , and air,tends to help reduce an engines tendency to detonate , a return style fuel pressure regulator and some thought put into routing your fuel lines away from obvious heat sources like headers will help reduce the fuel pressure and avoid problems like vapor lock ,or hard starting in hot weather.
    your ideally routing your fuel line well away from your engine and exhaust so your in theory not dealing with fuel line temps at any point much above 200F.
    keep in mind that most engine compartment fuel lines are metal except for the last 12"-18" of flex tube, engine compartment temps commonly run in the 160F-210F range but if you correctly plumbed your fuel line routing and used a return style fuel pressure regulator the constantly changing flow of fresh fuel thru the fuel lines will absorb and transport a good deal of that absorbed engine heat out of the fuel lines before it reaches the carburetor or inspector fuel rails..the rubber or synthetic fuel line is a poor conductor of heat and there are insulated reflective covers available.

    Performance Fuel Hoses Aeroquip Hoses
    These Aeroquip Performance...

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    Performance Fuel Hoses Aeroquip Hoses
    These Aeroquip Performance hoses represent the traditional hot rod hoses we've always used. From top: AQP-core, stainless braided racing hose with new black or classic red and blue hose ends; budget Socketless, AQP-core, textile-braid racing hose (both the black and blue hoses); and Teflon race hose with steel fittings, durable with a high pressure rating but stiff with a large bend radius.
    Developed in the early '50s for military aircraft, stainless steel-braided, chlorinated polyethylene (CPE) hose was designed to be reasonably compatible with a wide array of aircraft fluids, with fittings that could be installed using simple handtools. Descendents of it still constitute the mainstream of today's racing hose market, with slight manufacturer-specific compound variations (Aeroquip, for example, calls its CPE compound "AQP").

    Even for aircraft, the specific hose compound was always a compromise-so it always degrades over time. For aviation, that's OK because the hose is always replaced after a prescribed interval before any serious harm can occur. But this also means that-even in the heyday of high-octane, leaded gas-CPE-based aircraft-style hose was never ideal for long-term, indefinite, highway use. If until recently it seemed to outperform parts store black hose even on a daily street driver, it was primarily due to high-quality, aerospace-type manufacturing techniques, the stainless braid's higher temperature resistance, and drastically lower operating pressures compared with the original aircraft applications (for example, up to 1,000 psi on an aircraft in the -6 or -8 hose sizes, compared with less than 100 psi even on an automotive fuel-injection application).

    Gas Pains
    But in the last decade, things started going downhill. Fuel chemistry has changed radically since the original hose was developed to resist high-octane aviation gas and jet fuels. Street gas was reformulated with weird additives and oxygenates. Reformulated gas can have up to 15 percent ethanol, and E85 (about 85 percent ethanol) is common in the Midwest. It's gotten to the point where there's at least 23 different regional street gas blends. The brew can also vary seasonally, and not every state imposes strict quality controls in the first place. Some blends have caused minimal problems, but others-particularly those with ethanol and other abrasive additives-cause drastic rubber compound degradation.

    Performance Fuel Hoses Teflon Hose
    New-gen, ultralightweight,...

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    Performance Fuel Hoses Teflon Hose
    New-gen, ultralightweight, flexible PTFE (Teflon) hose is now the first choice of top-tier racers. Brown & Miller hoses currently dominate NASCAR racing and many other pro racing series. Here, its hose was used to plumb a Sprint Car's fuel cell.
    Although not as bad as street gas, many leaded, competition-only gas blends now have aggressive additives, that-while still allowing the blend to pass a sanctioning body's fuel check-are almost as caustic as alcohol fuels.

    Whether with street or race gas, deterioration is accelerated when the car sits for a length of time. Some experts recommend purging the system, while others caution that the hose may dry rot if it doesn't remain wet. Knowing what to do is a real crapshoot. Definitely don't expect that bulk rubber-core racing hose bought years ago to still be viable even if it has just been sitting in storage. All rubber-based hose has a finite shelf life.

    EFI Raises the Bar
    Electronic fuel injection systems introduced yet more issues. Compared with carbureted systems, high-volume recirculation fuel injection setups have a serious effect on rubber-core hose due to the much greater amount of surface footage and volumes of fuel passing through them. Fuel returning to the tank on a recirculation-type system gets aerated, souring the gas and accelerating hose degradation because of increased oxidation and leaching of the tube elastomer. Additionally, more heat is transferred into the gas tank by fuel returning from the engine compartment, heating the fuel overall and further accelerating hose degradation. Today's engine compartments are also much hotter-at times approaching 400 degrees F-which impacts underhood hose big time. And fuel injection nozzles are easily clogged by rubber particles breaking loose from hose deteriorating on the inside.

    Fuel vapors also permeate through rubber hose. If your car sits in an enclosed garage, that fuel-like smell is partially vapor evaporating through the hose.

    Performance Fuel Hoses - When Good Hoses Go Bad

    Performance Fuel Hoses Aluminum Fittings
    Reusable, lightweight, aluminum...

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    Performance Fuel Hoses Aluminum Fittings
    Reusable, lightweight, aluminum fittings are becoming available for PTFE hose. These are Bonaco's rendition, which appear very similar to the traditional red-and-blue fittings we have always used. Pricing on smooth-bore, stainless-braid, PTFE hose has come way down.
    Import Contamination
    If reformulated fuel weren't bad enough, inferior Chinese hose and fittings have seriously contaminated the supply chain. These hoses and fittings may look like the real McCoy, but the hose compound may be the wrong formulation, the braid may not be correctly bonded or extruded through the rubber, the hose bore may not be concentric (causing eventual leakage or failure at the fittings), and the fittings themselves may be made from inferior alloys or have the wrong heat treat. There's no easy way to tell by looking at the outside. All we can say here is buy name brand parts from a reputable manufacturer or distributor.

    One workaround is to inspect and replace rubber hoses in a timely manner, just like aircraft mechanics have always done. Savvy racers have known this for years, but on the street, the usual approach is to only replace on failure. That's not too big a deal with a generic parts store hose, but it's aggravating when it's a trick hose with expensive fittings. Still, if you are going to continue using CPE- or nitrile-based hoses, proactive maintenance needs to become as routine as an oil or fan belt change. Hose makers we talked to were reluctant to recommend a specific replacement interval, but empirical field experience suggests this may have to be done every 12 to 18 months. The ideal solution would be to just say no to traditional rubber-core hose-assuming there are better hoses available for substitution. Fortunately, modern technology has provided both low- and high-end alternatives.

    Performance Fuel Hoses Stainless Braid Hose
    A new player in the lightweight...

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    Performance Fuel Hoses Stainless Braid Hose
    A new player in the lightweight hose market, TechAFX sells the same PTFE-core, stainless-braid hose used on new GM cars, but unlike the General it has both OE-style quick-disconnects and a large variety of field-installable, black-anodized, aluminum hose ends. So far, TechAFX hose is offered in -6 (3/8), -8 (1/2), or -10 (5/8) sizes; hose and hose-end pricing is within 10 percent of stainless/CPE-core hose.
    Budget Solution: J30R9
    If you just want reasonable longevity at a modest cost without regard to appearance, the budget, parts store solution is hose meeting SAE standard J30R9 or (just becoming available) the further improved J30R12. Although these hoses can operate at up to 180 psi, what really makes them better than generic parts store hoses are the improved materials they're made from, designed for contact with alcohols, diesel, oxygenate additives, and oxidized gas. Although the outer walls are usually still hydrogenated nitrile butadiene rubber (HNBR) or CPE, internally there's a thin fluoroelastomer, FKM, or Viton core. Collectively, the design also resists cracking caused by sour gas and reduces emissions because fuel can't evaporate through the hose. XRP is said to be working on a braided racing hose conforming to SAE J30R9 that may eventually replace traditional CPE-cored formulations. This would offer significantly improved durability but still keep down the price of race hose. We'll keep you updated on XRP's progress. While J30R9 is better than old-school fuel hose, like any rubber-based hose, it, too, eventually deteriorates. In fact, domestic OE new-car manufacturers have pretty much switched to Teflon-based hoses.

    Solution: Teflon
    We may call it Teflon, but that's actually DuPont's trade name for polytetrafluorethylene (PTFE), a synthetic fluoropolymer that is stable at very low and high temperatures and chemically inert to everything except acid. PTFE hose is so durable that, absent crash damage and assuming proper installation practices, it should outlast the life of the car.

    Performance Fuel Hoses Orme Brothers Hose
    These Orme Brothers hoses...

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    Performance Fuel Hoses Orme Brothers Hose
    These Orme Brothers hoses illustrate today's wide variety of hose choices. From bottom: Stiff, high-pressure PTFE hydraulic hose; Brown & Miller flexible, lightweight, convoluted PTFE hose with black polymer braid, green/blue fire-retardant Nomex braid, or (in two different sizes) black/blue polyester cover; and XRP flexible PTFE dark gray/yellow Kevlar that's uniquely smooth on the inside but convoluted on the outside. Swivel-after-assembly elbow (arrow) eases double-elbow installations.
    About the same time the aerospace industry developed medium-pressure, rubber-cored hose, it began PTFE hose development for high-pressure, hydraulic-impulse systems that by the late '50s were pushing 3,000 psi. PTFE hose eventually found its way into racing applications, primarily for brakes, hydraulic clutches, and power steering systems. Originally, PTFE was much costlier than CPE. It was also very stiff, with a bend radius at least twice that of CPE-based stainless braided hose. The available mild steel or stainless steel PTFE-compatible hose ends were heavy and bulky in the larger dash sizes typically used for fuel systems, with only a limited selection of elbow angles available. More recently, Earl's, Goodridge, TechAFX, and others introduced a wider variety of fittings in aluminum, but that still didn't solve the bend radius or cost problems.

    The picture started changing once the OEMs started to use PTFE-based hose for fuel systems. Original extreme high-pressure PTFE hose was way overkill for even an EFI system, so the new PTFE fuel hose developed at OEM instigation traded off unnecessary extreme high-pressure capability for a tighter bend radius-some high-end versions have less than half the radius of even traditional stainless braided CPE racing hose.

    Professional racers then did the OEs one better, adding extreme light weight to their list of desired hose attributes. A stainless outer braid may have been a lightweight answer in the context of the '60s, but polyester, synthetic polymer, Kevlar, and other exotic new materials can save even more weight while still providing adequate abrasion protection and (with Kevlar) high-heat resistance on a par with stainless steel. Pioneers in the racing market such as Brown & Miller, Goodridge, XRP, and Earl's have also introduced ultralight PTFE hose that's now a must-have item for high-end racers. Meanwhile, Aeroquip says it has several programs in the works to address this emerging market; expect to see some new hose designs later this year.

    Depending on the specific exotic-outside-braid material used, ultralight, exotic-braid, PTFE hose may be anywhere from 3 to 15 times the cost of traditional CPE-based hose. But thanks to the big OE production volume, the cost of reasonably tight-bend-radius PTFE fuel hose with stainless braid is way down, often within 10 to 20 percent of CPE racing hose if you shop around. There are even some places selling the older, stiff, high-pressure/large-bend-radius PTFE hose for the same or lower price than CPE racing hose. And considering its unlimited life span, PTFE's actual life cycle cost is much cheaper in the long run.

    Performance Fuel Hoses - When Good Hoses Go Bad

    Performance Fuel Hoses Couplings
    Available for both hose and...

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    Performance Fuel Hoses Couplings
    Available for both hose and rigid tubing, clamshell-style quick-disconnect couplings like this one from XRP are increasingly popular in the racing world. They snap together with no tools. Even when joining two lengths of rigid tubing, the clamshells offer excellent flexibility with up to 1/4 inch axial adjustment and ±4 degrees of angular misalignment.
    Smooth OR Convoluted?
    Today PTFE hose is available in a traditional smooth bore or with a convoluted (ribbed) bore. Depending on the specific manufacturer, the convoluted design may have a slightly tighter bend radius capability than a roughly equivalent smooth-bore hose. You may also soon see a radical new convoluted hose from Goodridge with an extreme bend radius beyond anything yet seen.

    Smooth-bore adherents claim that fuel flow is slightly higher compared with convoluted hose, but Brown & Miller's Martin Clark counters that fuel flow in convoluted hoses does not encounter problems until fuel velocity exceeds about 70 gpm (gallons/minute)-that's Top Fuel territory.

    Whether smooth or convoluted, PTFE hose intended for use in fuel or oil system applications should have a small amount of carbon impregnated into the tube bore. Low-conductivity liquid fuels such as oil, gasoline, and diesel have the potential to create an electrostatic discharge due to external environmental factors like high temperatures and humidity. Without the carbon to act as a grounding agent, there is the chance of a spark-inducing electrostatic discharge. Carbon-impregnated PTFE hose can be identified by its gray-black internal core instead of the usual pure white found in industrial-grade PTFE hose.

    Performance Fuel Hoses Ultraflex 650 Hose
    Sixty-percent lighter than...

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    Performance Fuel Hoses Ultraflex 650 Hose
    Sixty-percent lighter than stainless-braid/CPE-core hose, Earl's Ultra-Flex 650 hose combines a woven, ultralight, Kevlar braid with smooth-bore PTFE tubing. In -6, it has a 1,180-psi operating pressure, a 0.787-inch bend radius, and a -94-to-500-degree-F temperature range, but so far only crimp-on fittings are offered. HRM
    Reusable Fittings
    One of the downsides of tight-radius, lightweight PTFE hose was that only swage- or crimp-on fittings were offered at first. That was no problem for OE automakers or high-end race teams, but it is a drawback for the home mechanic living far out of town. Brown & Miller, Goodridge, and others now offer aluminum fittings that you can install at home with simple handtools just like on traditional racing hose, however, for ultimate weight savings, the swage- or crimp-on style is still lighter and more compact. Moreover, most major hose companies and many of their authorized distributors such as Orme Brothers and Bonaco can make complete crimp-on assemblies to spec or per sample. Brown & Miller can also swage PTFE hose directly onto hard line, eliminating union fittings with their extra leak-point potential, or even come up with uniquely bent assemblies to order.

    It is this writer's opinion that some PTFE-based hose variation will increasingly become the performance hose of choice for all hydraulic, fuel, and even oil systems. PTFE prices will continue to drop, fitting variations will proliferate as they did with traditional CPE hose, and eventually nearly all of us will use PTFE hose for just about every application from grocery-getters to race cars. Next time your rubber-core hose gives out, why not upgrade to PTFE? It'll be the last hose you ever install.

    Hose Durability Test
    SAE J30R9 or J30R12 hose may be the most compatible rubber-based hose formulations out there for today's street gas, but they still can't hold a candle to PTFE hose. TechAFX is a business partner with and performance outlet for StanPro/Cooper Standard's engineered PTFE hose assemblies; it asked StanPro to utilize its TS969 ISO-certified lab for comparing the hose compounds' performance using the industry-standard SAE J2260 aging/temperature-soak tests running industry-standard "Fuel C" (a nonexplosive fuel mixed with methanol that safely replicates today's gas).

    Ten examples of both J30R9 hose and TechAFX Teflon hose were placed in separate thermal chambers: one set at 40 degrees C (104 degrees F); the other at 60 degrees C (140 degrees F). At specified time intervals, the hoses were removed and pressure-tested to their failure point to document any performance degradation.

    As can be seen in the graph, the J30R9 rubber hose saw almost immediate deterioration. The failures occurred first at the hose and fitting mating point, with the failure point dropping almost 160 psi (a 25 percent capability decrease) as the hoses aged. The PTFE hose saw virtually no degradation or performance decrease. There was also about a 10 percent fuel boil-off through the J30R9 hose, and none from the Teflon.

    Performance Fuel Hoses Old Versus New
    Old Versus New
    These cutaways show the material differences between CPE-core/stainless-braided racing hose; standard, high-pressure, stiff, stainless steel-braid PTFE hydraulic hose; and examples of new high-end PTFE-core fuel hoses: XRP's HS-79 PTFE-core fuel hose with extra layers of silicone, Nomex/Kevlar, and optional Hypalon outer coating. While the CPE and PTFE hydraulic hoses have higher pressure ratings, for pro fuel system use, the HS-79 outclasses them in every other respect. The figures below are for the -6 (3/8-inch) size.
    keep in mind that thats the minimum required, a fuel system has restrictions to flow rates like filters ,fitting and internal line flow restrictions requiring you to have a slightly higher actual supply volume and pressure

    In the automotive world, hose size is expressed by inside diameter. For example, a 3/8 inch has has a nominal (approximate) inside diameter (ID) of 3/8 inch. Not so with aircraft hose. Aircraft hose uses dash numbers to designate the hose size.
    Dash size is in 1/16 of an inch. So

    -2 (2/16) 1/8 inch,
    -6 (6/16) 3/8 inch,
    -8 (8/16) 1/2 inch and so on.

    But be careful, this does not mean that a -6 hose has an inside diameter of 3/8 inch. In fact, it can be anywhere from .298 to .359 inch, depending upon the hose type.

    Common aircraft hose dash sizes are:

    -2 Smallest hose size. Used as an instrument gage line
    -3 Also used as an instrument gage line
    -4 Common hydraulic line. Some smaller fuel line
    -6 Common size for fuel delivery lines
    -8 Fuel delivery and oil cooler lines
    -10 Larger aircraft, oil and fuel
    -12 Larger aircraft, oil and fuel
    -16 Larger aircraft, oil and fuel

    The inside diameter of each hose and fitting dash size is found in size charts. A common mistake is to think all hose of the same dash size has the same inside diameter. There not

    A common mistake is to think that all fittings of the same dash size have the same inside diameter. They do not.

    A common mistake is to think that a straight -6 fitting and a 90 -6 fitting of used on the same hose should both have the same inside diameter. They do not. A hose with a straight fitting on one end and an angle fitting on the other end will have different inside diameters.

    AN fittings use a 37* flare. A brake line flare tool usually only makes 45* flares.
    read these threads and sub links









    Last edited by a moderator: Jul 27, 2016
  2. grumpyvette

    grumpyvette Administrator Staff Member

    heres some short videos on making braided fuel lines,but let me point out that the pros at most hydraulic supply stores can custom make your professionally assembled hoses for not much more that the cost of the hose and fittings if you know the exact length and type of fittings and sizes you need, in fact in many cases they charge almost nothing for assembly if you buy several custom fuel, transmission coolant or oil cooler lines.
    my local hydraulic supply also sells the lines fittings, different hoses and tools you might need if you care to do it yourself, and if your just using fuel line its generally far less expensive, to purchase fuel and hydraulic lines there than at the local auto parts stores.
    IF you do this a good deal GET THE CORRECT HOSE CUTTING TOOL

    using a hammer and chisel , or hacksaw on fuel line is NOT the correct route!
    http://www.youtube.com/watch?v=IxRx1KzN ... r_embedded

    http://www.youtube.com/watch?v=dkqO6wbK ... re=related

    http://www.youtube.com/watch?feature=pl ... uIoAa5RRBs



    http://www.harborfreight.com/28-inch-ca ... -6649.html

    these cost about $20 and work great on th AN-8 -AN-12 hose I use

    http://www.speedwaymotors.com/Heavy-Dut ... GoogleBase
  3. Randy_W

    Randy_W reliable source of info

    On a related note; In the mid seventies I had a '64 LeMans with a 326/4 speed and 389 GTO heads, cam and Tri-Power. I go to a little Harley shop and buy some clear "gas line" thinking that would look cool. Ran it to all three carbs from an aftermarket fuel block. Man that blue Sunoco looked cool going through there! A few days later my boss used it to go to the store a mile or so away from the body shop. I heard the fire alarm going off and didn't think much about it until the phone rang and it was him. He said he was driving down the road when the hood paint started bubbling, he stopped and smoke and flame was everywhere! I was able to salvage a lot of parts including the semi melted battery and intake and carbs. But I lost a really clean LeMans. As a side note this car was navy blue with red interior and as strange as it sounds, looked great!

  4. grumpyvette

    grumpyvette Administrator Staff Member

    many guys used this type of tubing for fuel line, THATS A HUGE MISTAKE AND FIRE HAZARD

    it looks like it works great at first on carb systems with low pressure fuel lines ,but a combo of engine heat and fuel slowly degrades the tubing, it gets stiff and brittle and frequently cracks causing fires, its never designed for use as fuel line or engine heat, its cheap but its not safe!
    yes we almost all used it back in the 1960s, and many guys had fires as a result, so no one I know would think of using it any longer.

    Ive seen lots of guys use aluminum fuel line, but Ive also seen several failures , aluminum is not nearly as resistant to wear and vibration damage as steel nor as flexible and easy to used as the stainless braid covered synthetic fuel line, with the crimped on AN style fittings that many hydraulic supply shops can fabricate to your exact specifications.
    why not carefully measure each section youll need and have a local hydraulic hose supply fabricate you each section with the ends required, its usually not expensive or time consuming, in fact I usually go down with a few connectors or ends to show them exactly what I need in threads or connectors and a diagram like the one you posted earlier

    and I label the diagram and make a list showing what each section length and the type of connectors to be used, I walk in, and with in 30-45 minutes walk out with every custom section I need the custom fabricated flex hose with ends and made from hydraulic hose compatible with fuel, with stainless braid outer covering that will handle 300 psi and 300F temps with no problem.
    I don,t remember exact cost on my last race car, but it had several short sections with swivel ends and two longer sections of fuel line with ends all in 1/2" inside diameter and all together all the sections cost me less than $120-$130 if Im remembering correctly



    http://www.hotrod.com/techarticles/engi ... ewall.html





  5. Randy_W

    Randy_W reliable source of info

    I learned a hard one! :(
  6. bob

    bob Guest

    I was just talking with a neighbor who used that reinforced clear plastic fuel line on his car back in the 1980s, it was on a mustang, he owned at the time, he used one of the clear plastic fuel filters and a couple small hose clamps ... well he says he remembers just about everyone used those back then, but he was sitting at a traffic light one day and started smelling strong fuel,odors, and smoke started coming out from under the dash and thru the air conditioning ducts, he pulled over to open the hood and found gas spraying in a fine mist from a crack in the hose that had turned yellow and hardened with heat and age in the engine compartment, the smoke was from the fuel mist hitting the hot engine,the crack was where the clamp was on the filter, he had no idea why the engine failed to catch fire. but he replaced the hose and filter , and when he got home he called a friend that he knew was using a similar set-up, the friend said he had already replaced his fuel line after having a small fire when he moved the cars air cleaner and busted the hose!

    BTW alcohol in fuel tends to cause aluminum to oxidize over time

    http://www.aemelectronics.com/universal ... ilter-1212

    Machined from 6061-T6 aluminum and hard anodized black
    Flows up to 12.32 gpm @ 45 PSI and 2.63 gpm @ 6 PSI with -10 port fittings
    Filters as low as 7 microns
    Viton o-rings and gaskets ensure outstanding performance when using gasoline, alcohol or gasoline/alcohol blended fuels
    End caps are machined with -10 AN female fittings with o-ring receiver groove
    End caps have pressure intensifiers for greater sealing of end gaskets
    2” OD x 10” length for easy mounting
    Commonly available replacement filter cartridges
    Laser etched with AEM logo, flow and filter replacement information

    The AEM High Flow -10 AN Inline Fuel Filter is CNC machined from 6061-T6 Aluminum and Hard Anodized Black. AEM’s engineers designed this filter with the racer in mind and with the intention of maximizing flow, filtration and ease of installation. The end caps are machined with -10AN female fittings with o-ring receiver groove that allow the filter to flow up to an astonishing 12.32 gpm @ 45 PSI and 2.63 gpm @ 6 PSI. All sealing o-rings and gaskets are made of Viton for outstanding performance when using gasoline, alcohol or gasoline/alcohol blended fuels. The commonly available replacement filter cartridges filter as low as 7 microns. The standard 2” OD allows for easy mounting virtually anywhere in the vehicle.
  7. grumpyvette

    grumpyvette Administrator Staff Member

    Common Fuel Delivery Mistakes and How to Correct Them
    by Barry Grant Inc. ©2004


    Fuel lines, filters, pumps, and regulating devices exist to deliver gasoline or alcohol from the fuel cell to the carburetor, and in a bypassing system return it to the fuel cell. Pressures and volumes vary depending upon the kind of fuel used (gasoline or alcohol) and the type of fuel system employed. With routine maintenance, a good fuel system will pay dividends; yet many cars are fitted with systems that fall below the necessary standards. With a little help from BG Fuel Systems of Dahlonega, Georgia, here is a list of the most common mistakes in competition fuel systems and a guide as to how to correct them:

    1. Incorrect fuel lines
    Do not use 1/4" - 3/8" o.d. lines on a racing fuel system between the fuel cell and the pump. Racers often joke about their first race car and how the fuel line was so small it functioned as the main jet. Ensure the fuel is supplied through lines that are of the correct size for the application. Remember fuel line size is determined by the system, not the vehicle! Push-Lok, stainless steel braided hoses, and aluminum tubing are the most common fuel lines used on race cars.

    2. Right-angle hose-end fittings from the pump to carburetor
    Avoid forged 90*elbow fuel fittings as much as possible. Although they are inexpensive and readily available, they're restrictive and frequently cause fuel flow troubles. Hose ends with angles of 90* & 45* should also be avoided if possible. Nonetheless, should it become necessary to use one, use radiused hose ends (90* bends) as they have much better rates of flow. They're manufactured from aluminum, equipped with swivel ends for a positive seal and are easy to install.

    3. Fuel pumps unsuitable for alcohol
    An alcohol fuel system differs from the gasoline alternative in several crucial respects. Fuel pressures in a gasoline system are typically maintained between 7- and 9-psi throughout the rev range, whereas alcohol carburetors require low pressures of around 4- to 6-psi at idle and 9- to 11-psi at fully open throttle. This is necessary to prevent the carburetor from flooding at idle and under light engine load, yet maintain the extra volume necessary for maximum acceleration. Engines producing around 500-hp can be fueled with a 15-psi mechanical pump in conjunction with a throttle bypass valve. However, for engines over 500-horsepower, a belt-driven system with a diaphragm valve, or poppet bypass should be considered. For overall reliability and performance, a belt-driven system is usually the better choice. When using a diaphragm bypass, BG Fuel Systems recommend it be installed close to the carburetor for faster response.

    4. Incompatibility between bypass and pump
    Throttle bypasses were designed to operate with block-mounted pumps and, similarly, diaphragm bypasses with belt-driven pumps. Never use a throttle bypass with a belt-driven pump - they must function in pairs and are not to be mismatched.

    5. Unsuitable fuel filter
    Fuel filters with conventional paper elements must not be used with alcohol. Because alcohol absorbs water, the paper and the bonding materials deteriorate quickly. As a consequence, particles can enter the float bowls, or get stuck in the needles-and-seats and main jets. Further, it's equally important on alcohol applications, to avoid filters with inadequate flow rates, and inlet and outlet sizes that are too restrictive.

    6. Neglecting routine maintenance on an alcohol system
    Although alcohol fuel additives can help prevent corrosion and provide lubrication for pumps and other components, alcohol can severely corrode metal objects, especially aluminum, if allowed to remain in contact too long. There is no substitute for a strict maintenance program, it will not only prolong the life of the carburetor and fuel system, but also keep it trouble-free. Alcohol will naturally absorb water from the air. This not only dilutes the fuel, but also adds to the corrosive effects of alcohol. After every race, the alcohol should be drained from the race car and stored in air-tight containers; a vented fuel cell is not considered an appropriate storage container. The fuel system and carburetor should also be thoroughly drained and flushed of any residual alcohol. Some racers will add gasoline to the empty fuel cell and run the engine until they are certain the carburetor is filled with gasoline. Other methods include removing the carburetor and flushing it with a cleaning solvent or lubricating aerosol sprays. Removing inlet and outlet fittings from the pumps, bypasses etc. and lubricating the internals is also an acceptable practice. Whatever the method, maintenance on an alcohol system is crucial; ignore it and the system will fail.

    7. Failing to use a high-flow air cleaner
    Race engines rely on receiving air as well as fuel, but are frequently starved by the use of thin, small-diameter air filters that are detrimental to their performance. If possible, use a filter that is 14"diameter x 4"tall. If clearance is at a premium get one with a recessed pan, which allows for deeper filter elements. Get a good quality air filter. If you're constantly cleaning lots of dirt from the surface of your race car the chances are your air cleaner is struggling to filter the dirt and debris from your engine.

    8. Deterioration of foam-filled fuel cells
    Modern military-spec foam-filled fuel cells, are compatible with conventional fuels, racing fuels and alcohol. However, alcohol can cause the foam to deteriorate and it must be renewed once a year. To check the condition of the foam, simply remove the cap and pinch it between finger and thumb. If pieces come away the foam must be replaced.

    9. Not having proper linkage travel and return springs
    Make sure that, at wide-open throttle, the butterflies of the carburetor are fully open. Use a minimum of two, good quality return springs - preferably of stainless steel and employ them, if possible, in two different places on the linkage. Ensure the linkage and the return springs operate without interference throughout the full range of throttle travel.

    10 Failure to use an adjustable pedal stop.
    It's amazing to consider the large numbers of race cars that have no form of throttle-pedal stop, and inexcusable that so many are permitted to compete. Excessive loadings on the linkage, carburetor shafts and butterflies can cause the mechanisms to distort and jam, and the consequences are usually grim. To avoid the inevitable, use an adjustable pedal stop and, at the fully open throttle position, synchronize the stop on the carburetor with the stop on the pedal.

    11. Not having the proper size of carburetor for the application.
    Having the proper venturi sizes for a given application ensures the carburetor generates sufficient air speed. Air speed creates the necessary depression (low pressure) to draw fuel through the metering systems and booster venturii into the air stream to be atomized. The Race Demon, which is equipped with removable venturi sleeves and boosters etc., overcomes most of the sizing problems.

    12. Inadequate fuel cell venting.
    If the fuel cell vent is too small the fuel system can malfunction. In extreme cases, inadequate ventilation can cause permanent damage to the system. As the fuel pump draws fuel from the cell it needs to be replaced by air. If the vent on the cell is too small the pump will try to draw the fuel from the cell faster than the air replaces it. This can create a vacuum in the cell, distort its shape, and starve the pump and engine of the fuel it requires.

    13. Filtering of fuel cell vents.
    Just as an undersized vent will adversely affect your fuel system, not having a filter on the vent will cause dirt and debris to enter it. As air replaces the fuel, the vent hose will attract anything that's in the air, including dirt, sand, or debris. These particles will eventually destroy a fuel system as well as an engine.

    14. Fuel filter location.
    To protect the fuel pump and carburetor, use a good filter before the pump, and filtered fittings at the carburetor.

    15. Inspections.
    Steel braided fittings and aluminum fittings have a life cycle. Over a period of time, the rubber bore will deteriorate causing the line either to collapse and starve the engine of fuel, or disintegrate and possibly block the passage. Radiator hoses and fan belts are routinely replaced and so, too, should fuel system components. Aluminum fittings will wear out over time and fail to seal properly. From a safety and performance standpoint regularly check the lines and fittings. Try to detect soft or weak spots by feeling the outside of the lines, and visually inspect the internals each season. Keep the connections tight.

    16. Relays for electric fuel pumps
    On cars equipped with electric fuel pumps, use a relay to ensure the pump is provided with the proper voltage in order to maintain proper fuel flow.
  8. grumpyvette

    grumpyvette Administrator Staff Member

    hey grumpy? I have a couple old fuel lines that have started to leak and I can,t get the lines with the prefabricated ends from G.M. as they are listed as discontinued.


    Thats hardly a rare situation on older cars, if you have the old fuel lines, or or the old fittings on those old fuel lines or can find those fittings in a local salvage yard, you can bring the exact fittings and measurements or in a best, case, the old fuel line assembly with the ends still attached ,too any good local hydraulic hose supply, store and they can fabricate you new ones fast and easily, if you can,t get matching fittings, you can usually get either adapters or swap the matching fittings to match both sides of a connection.
    you can also get most fittings or adapters as manufactured tend to use whats available and fairly cheap.
    now you might need to search a bit but you can usually find the matching hose fittings or have both sides of a connection point converted to a match set.
    or the parts can be re machined to a different thread size or type of thread or new fittings can be welded in place










    read the details carefully when you buy a fuel filter, rated pressure, fuel flow rates, and fuel line sizes are all important in making your selection.
    from an engineering stand point a AN#6 fuel filter rated at 130 gph at 75 psi ( linked above ) is likely to flow CONSIDERABLY less than the rated 130 gph fed by a 9-11 psi feed from a manual fuel pump,how much less obviously will be dependent on the filter medium and its surface area, and how long its been in use.
    sintered bronze inserts used as filters are noted for clogging up fairly quickly, as the total surface area is not that great.

    a filter like this is larger longer and far less restrictive to flow, but takes up more room , but with a replaceable paper filter rated at 12 GPM (thats 720 gallons per hour GPH) its also a better deal on a performance car if you have room and use an#8 fuel lines
    if you do a bit of research youll find that those combo water separator & fuel filter combos come in dozens of different configurations and flow ratings.
    these are ideally mounted near the fuel tank where you can easily access and replace parts,
    that particular one pictured first,below is rated at 90 gph which for the application is adequate.
    youll find this type filter mostly listed in marine applications and for diesel fuel, but they can be used for gas in carb applications.
    be aware that you must carefully read the fine print on specs ,some of these filters Ive seen ar 4" in diam. and 14" tall, some are 2" diam. and 4" tall making them more reasonable for automotive use, some have CLEAR fuel bowls with a drain, sone have a drain but you can,t see the fuel thru the filter, most cars use 1/4" or 3/8" NPT or smaller fuel hose fittings some of the marine filters have fittings up to 1" NPT which by automotive standards is HUGE!

    http://www.amazon.com/Moeller-Separatin ... _sbs_sg_12

    http://www.amazon.com/Moeller-Separatin ... d_sbs_sg_1

    http://www.amazon.com/RACOR-500FG-EQUIV ... _sbs_sg_16
    http://www.amazon.com/Racor-320R-Rac-Se ... _sbs_sg_11

    http://www.jamestowndistributors.com/us ... 378&AMAZON

    yes I also think that the use of the ETHANOL protective fuel additives is a smart move, when dealing with the current pump octane gas laced with ethanol thats so damn destructive, when used in smaller engines or older car engines that were never designed to use it, or cars that get limited use, that sit with old fuel for weeks, between use.

    obviously you can elect to buy gas with no ethanol content but its expensive in smaller quantities. but ok if your using it in a chain saw or weed wacker
    http://www.trufuel50.com/product-info/? ... Mgod9FEAQg

    Last edited by a moderator: Jan 4, 2016

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