What to do with the vent port on a fuel sending unit.

We get asked very often what the purpose and what to do with that 3rd vent port on fuel tank sending units. 

What does a vent on a fuel tank sending unit do?

A vent is an important part of your fuel system as temperature changes occur either from outside environmental factors or the heat introduced into a system from operation of the fuel pump the fluid and vapors within a tank expand as fuel system temperatures increase and retract as the fuel system temperature goes back down. 

Can I cap off my fuel system vent?

NO, you must allow the fuel system a way to relieve system pressure and equalize the pressure with the surrounding environment. The only way to get around utilizing the fuel sending unit vent is by running a vented gas cap in it's place but at the end of the day the system needs a vent. 

 What do I do with the vent port?

On a factory system this vent likely vented out to a charcoal canister which kept fuel vapors from stinking up the garage. Most aftermarket builds have had this system removed entirely in which case you can install a roll over valve onto the vent port. A rollover valve will prevent fluid from leaking out of the gas tank in case of a vehicle rollover. See HERE for our rollover valves. 

Symptoms of a clogged fuel tank vent. 

Some symptoms that you may experience if your vent is blocked on your fuel tank. 

1. Reduced fluid fill volume
2. Reduced power levels at high throttle
3. Pump starvation and/or loud fuel pump
4. In extreme cases the tank may collapse
5. No start/no prime on the fuel pump

As you can see something as simple as a vent can cause a number of issues with your vehicle. 

How to choose the right fuel pressure regulator.

With so many regulator options on the market how do you know which one is the right fuel pressure regulator for your install?

Deadhead regulator, bypass regulator, return or return-less, efi or carb. A ton of questions come up when thinking about pressure regulation and what is the best option for your fuel system install on your car or truck. This article will take you through some of the most common considerations when selecting a fuel pressure regulator as well as make some suggestions on products that we have found work well for our customers. 

How does a fuel pressure regulator function?

How do Return style or bypass regulators work? 

A return style regulator or bypass does exactly what the name implies, it bleeds off excess pressure in a return line back to the fuel tank. As the regulator sends excess pressure back to the tank you can expect a reliable operating pressure supplied to the fuel rail or carb. 

This pressure is controlled with a bypass valve that is spring actuated. As fuel flows through the regulator pressure increases in the system which forces the spring to open the bypass valve and allow the excess pressure to bleed off. Many aftermarket bypass regulators are adjustable, this means that you can adjust the seat pressure provided by the spring and adjust the pressure that the system will see at the carb or fuel rail.

Return style or bypass regulators are recommended for most EFI installations as well as carb installations when a high pressure pump is used. 

Advantages of a return style bypass fuel pressure regulator. 

- Fuel is always flowing through the system helping to keep the fuel temperature within operating conditions. 

- Allows high pressure pumps to operate at maximum efficiency

- Generally required for many installations

Disadvantages of return style bypass regulator. 

- Return line is a requirement increasing system complexity

How do Deadhead regulators work?

A deadhead regulator controls pressure in a much different way than a return style or bypass regulator. There is  no return line and as such when the pressure increases beyond what has been set the spring will close a valve to restrict fuel flow and in turn the pressure the system sees after the regulator decreases to the set amount. 

Advantages of deadhead style fuel pressure regulators.

- Simple one line installation

- Can be used in systems with a single pump but multiple regulators. 

Disadvantages of deadhead style regulators.

- Can not be used for most EFI systems

- Allows for an increase in fuel temperature

- Can be hard on the fuel pump as increased pressure is needed to close the valve.

- EFI pumps with this style of carb regulator can not be used.  

Do I even need a fuel pressure regulator?

There are a few considerations here if you need a fuel pressure regulator in your system at all. These relate mostly to the fuel pump you will be using for your application. Certain fuel pumps on carb systems are self regulating, this means that they will put out the pressure needed for the carb system usually 4-6 PSI.  

PWM or pulse width modulation fuel pressure control that some factory EFI systems use do not need to be externally regulated. 

Return Style LS engines already have a fuel pressure regulator built into the fuel rail so an external regulator is not needed. 

What type of fuel system do I have?

The first step in making a fuel pressure regulator decision is to identify what type of install you are planning. As stated earlier if you have a system that already has a regulator or if you have a self regulating pump there is no need to make any further decisions. Read on to learn about what is required for other fueling applications. 

Carbureted systems

Low pressure mechanical pump - Usually no fuel pressure regulator needed.

High pressure mechanical, high flow mechanical, and belt driven pumps - A regulator will be required, most likely a return style regulator but this will be determined by each pumps manufacturer. Higher horsepower applications will most likely need a return style regulator. 

Low pressure electric pump - These pumps can come in multiple flavors, some will be self regulating and will not require a regulator. They are often sold with a predetermined pressure range so be sure to select the correct one for the operating pressure needed by your carb. If the low pressure electric fuel pump operates above what your carb requires then a deadhead style regulator is usually warranted for this application. 

High pressure EFI electric fuel pump - A return style regulator designed for carburetors is required. We recommend the Aeromotive 13301 found HERE. This regulator will allow you to setup for carb but also if you plan to convert to EFI at a later date you will be able to swap the spring and convert back. 

EFI systems (non direct injection)

There is less combinations available for EFI systems as you must run a high pressure fuel pump that meets the needs of the system and power targets. Running a low pressure pump is not an option and as such you must regulate the pressure in these installs. 

LS swaps with a return-less intake. A factory style corvette regulator is perfect for these installs up to a fuel pump flow rate of 255LPh. The regulators can be found HERE with AN fittings or we also carry a complete LS swap kit that includes the corvette style filter/regulator unit found HERE. The nice thing about these units is they double as a fuel filter reducing overall system cost. 

LS swaps with a higher flow fuel pump and other EFI systems that require a different pressure than 58 PSI. An adjustable fuel pressure regulator with return is required. We recommend the Aeromotive 13129 found HERE. This regulator features a gauge port built in and will support builds up to 1000HP. 6 ORB ports for feed and return allows you to adapt it to many different fuel systems. This regulator is also boost referenced if you require that feature. 

Fuel systems with extremely high flow rate pumps and high power levels over 1000HP. With these installations we recommend that you reach out to us to discuss all the variables in your install our customers have had great luck with the Aeromotive X1 pro regulator found HERE. 

EFI systems with Direct Injection. These systems require a higher initial operating pressure and from OEM are usually controlled using a PWM system for regulation. With GM gen V motors for example while they will operate with as low as 58PSI you may have struggles getting the engine to operate correctly. We recommend setting the regulator at 72PSI if you insist on running the non PWM system. Of course the best course of action would be to do what the GM engineers intended and setup the PWM system for the best chance at success. 

 How do I route my fuel pressure regulator. 

There are a number of different ways to route a fuel pressure regulator. The way you route the system will depend on multiple factors including how much power you will make, what type of regulator you choose, what type of fuel rails and more. 

In all cases the manufacturers of the regulators will suggest the best way to route the lines. They have tested the installs of many vehicles to ensure reliable operation so if you are able follow these directions. Below you will see diagrams of common installs with a bypass regulator but once again we recommend to follow what the manufacturers suggest. Also to note we have not shown fuel filters in the system they will be required before the fuel rails and regulators. 

LS corvette style fuel pressure regulator 58psi. 

Bypass return style regulator before fuel rails install

Bypass return style regulator after fuel rails (best for boosted applications)

 Do I need a gauge for my fuel pressure regulator? 

While not necessary to have one especially once you have set your base pressure a gauge can help to diagnose issues in your fuel system related to pressure. There are a few different ways to install a pressure gauge. The easiest way is to install it in the built in gauge port that many regulators include. The other option is to use a gauge port adapter fitting found HERE. 

Just remember that a gauge will read pressure for everything that is in front of it, if you install your gauge before your regulator you will not read anything close to what the engine is seeing for pressure. 

As for what gauge to use we recommend the Aeromotive 0-100 for EFI systems found HERE. It has an equalizer button that takes temperature differential out of the equation so in a hot engine bay you always get an accurate reading. 

How to identify if your LS engine is a return or return less fuel system. 

We often get asked what type of AN fuel line kit is needed for an LS swap and that starts with identifying if the engine uses return style fuel rails or returnless style fuel rails. 

On an LS based engine the fuel pressure must be regulated and this is managed with a fuel pressure regulator, where this regulator is placed in the system determines the type of system you have.

Return style fuel system LS engine

In what has been termed a return style fuel system the fuel pressure regulator is integrated into the fuel rail on the LS engine itself. In this type of system you will have a fuel line running up to the fuel rail and return line also coming back from the fuel rail. In a return style fuel system you will require an in-line fuel filter 10 micron or better to complete the system. This type of system can be identified as the fuel rail will have fuel ports for both the fuel feed line and fuel return lines. 

Return-Less style fuel system LS engine

The Return less style fuel system has misconceptions about what return-less actually means. In this style of fuel system the fuel pressure is externally regulated. The fuel pressure regulation can be accomplished a few different ways, usually when doing an LS engine swap this is accomplished by utilizing an external fuel pressure regulator.

Corvette style filter and regulator unit

Our Return-Less LS engine swap kits include a "Corvette style filter regulator"  that regulates the LS engine to the needed 58 PSI this unit also doubles as the fuel filter and is a very cost effective way to regulate the pressure. The limitation with this regulator is in high flow fuel systems it may not be enough, this leads us into aftermarket adjustable fuel pressure regulators. 

Aftermarket fuel pressure regulators

Aftermarket regulators will allow the required fuel pressure to be set but also support high flow fuel pumps. You will need an inline fuel filter with these aftermarket fuel pressure regulators. Aftermarket regulators can also be adjusted to support advanced tuning and often times are boost referenced so that they increase fuel pressure as boost increases again to aid in tuning of the LS engine. 

Other fuel pressure regulation methods

Internally regulated modules OEM and Aftermarket

The two less common methods of regulating fuel pressure for LS engine swaps are the us of internally regulated fuel pump modules, these exist in certain OEM systems as well as some retrofit fuel pump units by various aftermarket manufacturers. The advantage of some of these systems is simplification of the install as only one fuel line to the engine is required making them truly "return-less" these systems are usually system specific so we recommend you reach out to us for assistance in selecting the correct unit for your application. The disadvantage of this type of system is serviceability, if you have issues with the internal regulator you will be dropping the fuel tank. 

PWM or Pulse Width Modulation

While very common in newer OEM applications PWM is less common in the aftermarket. With this method the fuel pressure is controlled by the Engine ECU. While possible to implement it does take more work to accomplish an engine swap. The ECU controls the pump by applying signals to control the output of the pumps volume and pressure thereby delivering the fuel needs to the engine. 

Always happy to help

If you have more questions about what fuel system is best for your application please Contact US and we will be happy help. 

Using Hot Rod fuel hose AN PTFE Hose and Fittings for Transmission cooler lines

Can you use AN PTFE hose for transmission cooler lines?

A simple answer to this question is absolutely. Due to the chemical properties of PTFE hose it's a perfect fit for using braided lines for your transmission fluid lines. 

Using the correct AN Adapter Fittings

Transmission cases use different fittings then you will find in other car plumbing applications. Due to the fact that transmission cases are often constructed from aluminum it is very important to use the correct adapter fitting to prevent the aluminum transmission case from splitting. 

A common misconception with Transmission Adapter AN Fittings

If you start searching the internet for what fittings you should use to convert your transmission cooler lines to AN fittings and hose you will often be advised that NPT (National Pipe Taper) fittings will work for this application. Often times transmissions use what is called NPS or National Pipe Straight. As the name implies the threads of these fittings are cut in a different manner. An NPS fitting will seal typically using a nylon crush washer where as NPT fittings seal by apply pressure on the tapered threads of the fitting itself, this is what can cause your case to split when attempting to use NPT fittings in place of the required NPSM adapter fittings. 

How do I know what adapter fittings to use

Hot Rod fuel hose has made it easier to get the correct transmission cooler line adapter fittings by allowing you to simply select your transmission type from a drop down list. We have done the hard work researching this information for you. The transmission to AN adapter fittings can be found HERE. 

If you don't see your transmission listed please reach out and we would happy to do the research and add the correct adapter to our list. 

How much PTFE AN hose do I need to use?

When deciding how much line is required to install your transmission cooler you need to evaluate whether you will be using the built in radiator transmission cooler, an external cooler by itself, or a combination of the two. 

Most standard installations use approximately 16-18 feet of AN hose. As each installation is different be sure to measure out the required line prior to placing your order. 

What fittings do I need on my transmission cooler?

This question is more challenging to answer in an article as there are a variety of options on the market. If using an aftermarket radiator or cooler you can get the specification for the fitting from the cooler manufacturer. We then offer adapter fittings HERE. 

LS fuel system swap guide for OBS 1988 to 1998 Chevy and GM K1500 / C1500 trucks

This fuel system swap guide will show you all of the parts needed to successfully install an LS engine into your OBS (old body style) Chevy or GM pickup truck. 

As the years pass by different generations of pickup trucks gain popularity, as original C10 trucks became harder to find guys started to build square body trucks and further along the popularity of the OBS Chevrolet and GM trucks has increased. With this increase in popularity builders have started to look at swapping LS motors into the trucks to gain the reliability and power only an LSx series engine can provide. 

Advantages of LS swapping an OBS 1988 to 1988 K1500 or C1500

When comparing the parts and work needed in completing a fuel system for an OBS LS engine swap to other series of GM trucks like the squarebody or original series old body style owners have the advantage due to this truck platform being originally designed for EFI fuel injection with the TBI system.

This means that you are able to install a high pressure fuel pump directly into the factory sending unit and avoid having to replace fuel tanks. There are special adapters available that allow a direct conversion from the factory TBI fuel fittings to AN helping to keep the fuel system portion as simple as possible. 

OBS TBI vortec to LS swap fuel system parts list

Here you will find a complete listing of all of the parts needed to successfully swap both return and return-less style LS engines into your old body style chevy or GM K1500 / C1500 truck. 

Return-less style LS swap parts list for OBS (old body style) trucks

The first thing that needs to be upgraded when completing an LS swap for these trucks is the fuel pump. You have multiple options to choose from when upgrading the pump each with there own benefits.

Your first option for an LS swap or EFI conversion with a factory power level up to 450HP is the 

Spectra Premium 190LPh Fuel Pump - HERE

For a bit higher flow and support up to 550HP the 

Walbro 255LPH pump - Found HERE

If you are producing a bit of extra horsepower the Aeromotive 340LPH is another good option. Again this pump will fit in the factory sending unit. There are other considerations with this pump such as regulator and electrical connections. 

Aeromotive stealth 340LPH fuel pump -Found HERE. 

Adapter fittings to convert factory sending unit to AN6.

M16 x 1.5 to 6AN - Found HERE

M14 x 1.5 to 6AN - Found HERE

The Hot Rod fuel hose Return-Less LS swap kit, for a return-less system you will need 20ft of hose if mounting the corvette regulator/filter close to the tank. Longer lengths of braided AN PTFE hose are available if needed. You can chose both your hose and fitting colors with this kit.

Return-less LS swap kits by Hot Rod fuel hose - Found HERE

 These parts are everything needed to complete this OBS LS engine install from a fuel line perspective. As always if you have any questions you can reach out to us on our Contact Us page. 

 Return Style LS swap parts list for OBS (old body style) trucks

The parts needed for converting a TBI OBS engine to an return style LS engine can be found below. 

As before you will need to replace the factory fuel pump with a high pressure fuel pump. The most popular of which is the Walbro 255LPH in tank pump. This pump is compatible with the factory sending unit and will deliver the flow and pressure needed to supply the LS engine. 

Walbro 255LPH pump - Found HERE

For higher horsepower applications the Aeromotive 340LPH continues to be another good option for return-style LS engines. This pump will fit in the factory sending unit. 

Aeromotive stealth 340LPH fuel pump -Found HERE. 

Adapter fittings to convert factory sending unit to AN6.

M16 x 1.5 to 6AN - Found HERE

M14 x 1.5 to 6AN - Found HERE

A fuel filter will be required in addition to the other parts with this kit, we have both factory style fuel filter options and aftermarket fuel filter options. 

Factory style fuel filter with AN adapter fittings - Found HERE

Aeromotive 10 Micron fuel filter (requires 10 ORB to AN fittings) - Found HERE

Holley 10 Micron fuel filter (requires 8 ORB to AN fitttings) - Found HERE

Finally the Hot Rod fuel hose return style LS engine swap kit will complete the needed parts for your OBS 1988 to 1998 GM or Chevrolet LS swap. For a return style swap you will require a 30FT kit to be able to run both the feed and return to the factory fuel rails found on the LS engine. 

Return style LS swap kit - Found HERE

LS or EFI swapping your C10 / K10 73 - 87 squarebody truck. This guide is for you. 

Tons of guys find our website when researching info on how to do new fuel lines for their squarebody 73 - 87 Chevy and GM trucks. We get asked enough times what else guys need in addition to our PTFE hose kits in order to complete the swap we decided it best to make a write up for everyone. 

In this fuel system write up for the squarbody pickup you will find links to what we have found to be the best parts to use in an LS swap or EFI conversion, some installation photos, instructions, and guidance on how to make the fuel system install go as smoothly as possible. 

There are many different ways to do a fuel system on any vehicle, these recommended parts and instructions are what we believe to be the best way to ensure an effective, affordable, and long lasting install. 

We will give you the parts list first so if that's all you came for you can get in and get out quickly. Note some of these items we don't sell directly so we have linked to the source in which we have found the best price in combination of shipping and product.  

Parts List(s)

Parts needed for all installations 

Fuel Tank(s)

Aftermarket Tank option

Tanks Inc. Squarebody EFI ready tanks (choose GPA 4 pump for 255LPh LS / EFI ready pump)

OEM 1987+ tank option

Long Bed truck Spectra premium GM1C - HERE

Short Bed truck Spectra premium GM11C- HERE

Fuel Sending Unit(s) - Select which side the fuel filler door is located

Spectra Premium FG05M and FG05N sending units - HERE

Conversion fittings to attach PTFE AN fuel lines to the sending unit(s)

1 of each needed per sending unit. 

5/16 Hardline tube to AN6 Adapter fitting - HERE

3/8 Hardline tube to AN6 Adapter fitting - HERE

Fuel Pump(s)

The following fuel pumps are compatible with the Spectra sending units. 

Factory power level up to 450HP

Spectra premium 190LPh Fuel Pump - HERE

Great for factory LS engines to slightly modified and stock engines with EFI conversions. 

Walbro 255LPH In Tank fuel pump - HERE 

Modified Engines to about 700HP boosted and 900HP naturally aspirated. (many factors come into play on these ratings so be sure to contact us if you are unsure)

Aeromotive 340LPH stealth In Tank fuel pump - HERE

Return - Style LS Engine swaps

We have created a universal LS engine swap kit for return style engines that includes all necessary fittings from the sending unit to the fuel rail. It is assumed you have followed the rest of this swap guide for your C10 or K10 square body truck and are using an in tank pump. Please contact us if you plan on using an inline pump as some other factors need to be considered. 

Return Style LS swap kits can be found - HERE

You will need approximately 25-27ft of PTFE hose in order to run both the feed and return on the fuel system. The 30Ft kit is the most common choice for square body LS swaps. 

You will also require a 10 Micron in Line fuel filter. We have three options.

The most popular option is the factory style filter with AN adapters, This unit filters at 5 micron and replacements are available at most auto parts stores. 

Factory style filter with AN 6 Adapters - HERE

OR

Holley 10 Micron inline fuel filter with replaceable element - HERE

Two (2) X ORB-8 to AN6 Adapter fittings for fuel filter - HERE

OR

Aeromotive 10 Micron inline fuel filter with replaceable element - HERE

Two (2) X ORB-10 to AN6 Adapter fittings for fuel filter - HERE

 Return - Less style LS Swap Kit

These returnless style ls swap kits include all fittings needed to install the returnless ls engine into a 73-87 c10 / k10 squarebody pickup. They include the corvette style filter / regulator as well as the adapter fittings to get it hooked up. Most guys mount this regulator fairly close to the tank and allows them to utilize the 20FT Kit. 

Return-Less style LS swap kit - HERE

No additional filter is needed with this kit. 

EFI Conversion - Including Holley Sniper & FiTech EFI systems

The nice thing about the EFI conversion systems is the majority include fittings that are compatible with AN standards. As such one of our regular hose bundles and a 10 micron filter is all you need to get hooked up in addition to the tank, pump, and sending units listed above. 

As these systems have the regulator installed in the unit you will require approximately 24-26ft of line. Our 30FT kits are the perfect option for an EFI conversion in your square body C10 or K10 pickup truck. 

Nylon Braided AN PTFE hose bundles - HERE

Stainless Braided AN PTFE hose bundles - HERE

Colored Nylon Braided AN PTFE hose bundles - HERE 

We have three options for fuel filters.

Factory style 4 Micron inline fuel filter with AN6 Adapter fittings - HERE

OR

Holley 10 Micron inline fuel filter with replaceable element - HERE

Two (2) X ORB-8 to AN6 Adapter fittings for fuel filter - HERE

OR

Aeromotive 10 Micron inline fuel filter with replaceable element - HERE

Two (2) X ORB-10 to AN6 Adapter fittings for fuel filter - HERE

Other Parts needed

In order to easily install the new line and fittings into your chev or GM C10 / K10 pickup we carry some tools that make the process easier and prevent marring your new fittings. 

Hose cutting shears for cutting AN PTFE hose - HERE

Aluminum anodized vice jaws for AN PTFE fittings - HERE

Aluminum AN wrench set for AN PTFE fittings - HERE

Now the fun stuff installing the kit's into your 73-87 square body chevy C10 / K10 truck. 

When you have the correct parts installation of your new LS engine or EFI system will be smoother than you ever expected. 

Hose fitting installation instructions can be found HERE, follow these instructions for the installation of the hose end fittings onto the PTFE hose. 

Fuel pump & Sending unit installation.

The fuel pumps we linked to earlier in this article are direct fit into the sending units. The complete install of the fuel pump, sending unit and hard line to AN adapters will allow you to hook up the PTFE hose kit that you choose for your relevant install. You will need to cut off the bubble flare on the end of the tubes in order to install the hardline to AN adapter fittings. Do not cut the center vent port unless you intend to also install a hardline to AN adapter for the vent. 

Return-less style regulator install

If your squarebody LS engine swap will be utilizing a return-less fuel rail you will require a regulator. If using a factory or only slightly modified LS engine the most common regulator to use is what is referred to as a corvette style regulator. This regulator also features a 4 micron fuel filter and regulates the pressure to the 58 PSI needed for a return-less LS fuel system. 

One common mistake with the install of this regulator is mixing up the feed and return lines from the tank. As shown in the diagram the 5/16" center port is the return while the 3/8" port on the perimeter or outside edge of the corvette style regulator is the Feed. The feed is generally marked by an arrow or a Flow marking. The feed from the regulator to the LS engine is the single center port that uses a push in fitting in 3/8" size. You will require adapter fittings to convert this corvette style regulator to AN fittings and AN ptfe fuel hose. Our return-less LS swap kits include all of the necessary fittings to hook up your PTFE AN line to your regulator/filter. 

Running Dual Fuel Tanks 

We often get asked the best way to run the factory dual tank setup found on squarebody C10 and K10 pickups. These dual tank installs can use an 87+ 6 port switching valve from Pollock as well as an 87+ dash switch. 

Unfortunately in order to hook up the AN hose to the switching valve hose barb to an adapter fittings must be used. The ports on the switching valve are 5/16 for the return lines and 3/8 for the feed lines. 

Choosing the right fuel pump for your LS engine install or EFI conversion.

One of the most common requests that we have come in is what electric fuel pump should be used in order to install an LS engine or to do an EFI swap. There are thousands of different fuel pump options when you look at factory fuel pumps, OEM replacements, aftermarket fuel pumps, high performance, E85 compatibility and high flow options.

So how can you figure out which is the best fuel pump for your LS swap or EFI install?

First, we need to determine your flow rate requirements and this is based on your horsepower goals and type of fuel used. If you recall from the article we wrote about hose size selection there is a formula you can use to determine the required fuel flow rate. That article can be found here. In the interest of saving you time we will showcase the most popular fuel pump options for LSx swaps and fuel injection installs and what HP they are capable of supporting including E85 compatibility.

Choosing an Inline fuel pump or an in-tank fuel pump – What is the best option?

Hot Rod fuel hose sells both in-tank and inline fuel pumps to support a number of different applications. Depending on the type of sending unit and tank or fuel cell you will be utilizing you may only have the option of running an in-line pump. If the horsepower level you are seeking will support an in-tank pump and you have that option we strongly recommend it.

Benefits of an In-tank fuel pump over an Inline fuel pump for LS engines & EFI

• In tank fuel pumps are considerably quieter, the sound they produce is muffled by both the fuel and the tank and therefore let’s you focus on the sweet exhaust note your engine produces.
• In tank fuel pumps operate at a cooler temperature as they are submerged in fuel in turn which helps to prolong the fuel pump life.
• The install appears cleaner and less fittings are needed on the fuel line.
• Low chance of cavitation (failure) of the pump due to constant fuel at the inlet of the pump (when using a baffled tank and a high enough fuel level)

Benefits of an inline fuel pump

• More install options for a wide variety of older vehicles and hot rods / street rods.
• On very High Horsepower applications it may be necessary
• Replacement of a failed pump can be completed more easily than in tank.

*Note when installing an inline fuel pump you should mount the pump as low as possible in order to reduce the chance of cavitation on the pump. As pumps are built to push fuel rather than pull fuel this helps to reduce the amount of work the fuel pump needs to do in order to get the fuel out of the tank.

Now that we have some background what fuel pump should I choose for my LS engine install or EFI swap?

Most LS engines operate at 58 PSI, as well the most popular EFI systems operate anywhere between 48 PSI and 58 PSI. The exception to this would be Gen V LS engines with direct injection which have a higher-pressure requirement. Always choose the proper fuel pressure regulator for your application. We have many different options that can be found here.

You will notice on the pumps below that those that are compatible with EFI have a lower HP rating compared with gasoline. The reason that this happens is that in order to produce an equal amount of energy or HP from E85 takes more fluid approx. 30% more for each unit of HP. All ratings are for naturally aspirated engines, boosted applications will have different flow requirements please contact us if you require a fuel pump for a boosted application.

550HP E85 – 650HP Gasoline (Naturally Aspirated)

Walbro GSL-392 In line fuel pump – the most common choice for factory LS swaps up to mild mod engines. 255L of flow and based off of the OEM design for corvette. Features 10mm x 1.0 inlet and outlets so be sure to grab the adapter fittings found on our website.

Walbro GCA-758 In Tank fuel pump – A widely universal in tank design based on a GM sending unit design. Is compatible with many different sending units across many different applications both factory and aftermarket. Conversion to Hot Rod fuel hose line and AN fittings will depend on the sending unit used please contact us and we will be happy to help you figure out which adapter fittings are needed. This pump features a 255L flow rate and is very popular for LS engine installs and EFI conversions.

750HP E85 - 950HP Gasoline (Naturally Aspirated)

Aeromotive 11569 – In Tank fuel pump – A great option for keeping a factory looking install using the OEM sending unit while supporting an increased flow rate to 340L. This pump follows the GM style design but still supports many different applications. A popular option for higher horsepower LS swaps and EFI installs.

Higher horsepower applications than this will need many more questions answered, we suggest you reach out and we would be happy to help you plan out your entire fuel system. As experts in the area of fuel delivery we would be happy to help you plan out your system from pump to rails. Contact us HERE

 As always Hot Rod fuel hose provides high quality hose, fittings, pumps, filters, and regulators for LS swaps, EFI conversions, and any other application where AN fittings and line may be used. Click below to check out all of our available products. 

SHOP NOW 

Some of you may know that we have listings on Amazon and one of our awesome customers who purchased our PTFE lined and black braided hose bundles from there left a nice review as well as some great tips for installation. We reached out and asked if we could share that info here for everyone else. 

Thanks Ian for the support. 

TL:DR great quality, fast shipping, excellent value.

A little background first: I wanted to switch out my rubber AN lines for PTFE. The rubber line does break down and I also experienced the fuel smell that comes with rubber breaking down.
From research, PTFE line will cure this.
The product: I ordered Sunday night, received Wednesday. Fast shipping. I wanted a few extras for plumbing that I ordered from Hot Rods website. Owner bundled both orders, no problem. Very responsive. I ordered 30ft. It comes with 8 fittings. This is where the great value comes in and owner hooked me up after a simple message. Easy.

Install tips. Wrap hose with tape prior to cutting, slide fitting on prior to trimming nylon wrap. Take off about 1/4” of the nylon wrap (more? not so good). Easiest method was newer scissors at a right angle to hose and just keep nipping up to the steel braid. Hot rod hose website had good directions. One other tip is to insure when ferrule is slid over the hose, the hose is concentric before sliding on the connector (see pic). Lastly, my best connection was used with regular box end wrenches, one chucked in a vice. My aluminum AN6 wrench was just not up to the torque needed to crank down connector. Very pleased with the whole deal.

Full disclosure: The first pic was how much I removed for first fitting. It was just a little too much nylon removed. If you want to see the result, zoom in to lower line of trans. Won’t affect performance, just cosmetic that no one sees. Next photo was using the procedure I outlined, perfect.

Do I need conductive hose on my build?

This question occasionally comes up when guys are researching PTFE AN braided hose for their own car builds. Here is some information on what conductive PTFE hose is and if you need to step up to conductive hose on your build. 

What is Conductive PTFE hose?

Conductive PTFE hose is hose that utilizes an PTFE liner that is also covered with a carbon coating in order to discharge static electricity. This carbon coating significantly increases the pricing of the hose. This hose follows standard SAE 100R14 Type B and appears black in color when you look at the liner. Typical SAE100R14 Type A hose appears white when looking at the liner. Type A is what is sold by Hot Rod fuel hose. 

How does Conductive PTFE hose work. 

As fluids flow through the hose at a high velocity friction caused by the moving fluid generates static electricity, if enough static electricity builds up within the liner there can be a discharge to the stainless outer liner of the PTFE hose. When this happens the electrical discharge can create a pin hole leak in the PTFE liner. The carbon conductive coated liner discharges this electrical buildup and prevents static shocks. 

Do I need Conductive PTFE hose?

Generally in most automotive applications Type A hose like what Hot Rod fuel hose sells works perfectly. If you are running gasoline in a very high flow system with a smaller sized hose you may be at risk and need to step up to conductive hose. The higher flow rate in a smaller hose size creates increased velocity of the fluid and therefore production of higher static build up. A properly sized system will prevent issues when using type A hose. If you are not sure please contact us and we will be happy to answer any questions around conductive hose and if it is needed for your application. 

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What you need for a successful EFI conversion - FiTech & Sniper.

With EFI conversions becoming ever more popular, a common question comes up around what you need to install them from a fuel delivery standpoint. 

The article focuses on applications up to around 600 HP, for other EFI installations like the FiTech 1200, Holley HP EFI, or Custom high performance mega squirt installs be sure to read our other articles on fuel hose size selection that can be found here.

With these installations you will be using AN6 hose and fittings commonly found in our bundles that come with a choice of hose length and fittings. You will need to measure out your fuel line length taking into consideration any bends or routing issues specific to your vehicle, engine mounting location and so on. 

What do I need for a fuel pump to feed my EFI system?

EFI setups operate at a higher fuel pressure compared to a carbureted install, this has impacts on the type of fuel pump you will be using. You can use either an in tank or in line fuel pump. Typically an in tank pump has a longer life due to the cooling effect of being submerged in liquid fuel. If you recall from our other article that talks about line size we can use math to figure out what flow rate is needed from our fuel pump. 

LPH = (HP X BSFC) / 1.585

BSFC = BRAKE SPECIFIC FUEL CONSUMPTION.

Therefore

(600HP X 0.5) / 1.585

Answer 189.27 LPH

Using a boosted setup on a system with a FiTech 600 Power adder for example would change this equation slightly. 

Based on this math what pump should I choose?

Well the most commonly suggested pump is the WALBRO 255L, GSL392 is your inline fuel pump part number. GCA758 is your most common in tank part number. Obviously with in tank pumps you need to check for compatibility with your sending unit. 

If choosing this Walbro inline pump you must also purchase two M10x1 to AN6 adapter fittings to link up the pump with our PTFE braided fuel hose. 

What else do I need to install my new EFI system?

Once you have selected the length of PTFE braided hose and fuel pump needed for your performance application you will need to make a few decisions around fuel delivery starting at your fuel cell or tank. In this instance we are using AN 6 sized fittings and you will need to adapt to this size to get started. 

Fuel Cells typically have AN bulk head fittings and will vary in size depending on the manufacturer. In this case you need AN to AN6 adapter fittings commonly available. 

Fuel tank sending units utilize more varied ways that you will need to adapt to. At times you may need to use tube to AN adapters if your sending unit was setup for rubber lines and hose clamps. Newer sending units have utilized a variety of different fittings. If you are unsure what you need to adapt to our line be sure to reach out and we can help you get what you need. 

Check out our AN PTFE lined and braided hose bundle offers HERE. 

Check out our AN PTFE hose end fittings HERE.

LS Swaps, what is needed from a fuel line perspective.

Welcome to Hot Rod fuel hose, one of the most common uses for our AN hose and AN fittings is for guys doing LS swaps. We get a ton of questions around what it takes in order to install an LS engine into an older vehicle so in this post we will answer the most common questions that we get around fuel lines for LS swaps. 

Ok, so getting fuel to an LS engine is pretty important, it won't run without a proper install. So in order to do it properly what do you need? We will answer that question here. 

What do you need for AN lines in order to install an LS engine into an older vehicle. 

First you need to determine the engine that you have, A return less setup or a return style setup. Both will have implications on your install. 

A Return - less setup - LS fuel line install with AN hose & Fittings

In order to run a successful LS swap install with AN fittings and hose without a fuel return you will need the following. Setup A will be all about running an inline fuel pump. Setup B will cover the differences with running an in tank pump. 

Setup A - You want to make sure that you run your new inline pump as low to the fuel tank as possible, the EFI pumps that you can purchase are made to push and not pull if you mount them where they need to produce vacuum they will fail prematurely. Often guys will install bulk head fittings into the tank to ensure a constant feed of fuel to the pump. For LS swaps an Walbro 255L inline is a very common install. This pump can easily be converted to AN6 style fittings to use with Hot Rod fuel hose lines and make for an easy fuel system install. Pre - pump you will want to install a 100 Micron Fuel filter to protect the pump from debris. Post pump you will want to install at a minimum a 30 micron filter, recommended is a 10 micron filter from your choice of manufacturers. Finally A regulator is needed in order to deliver the required PSI to the LS fuel rails. 58 PSI is what is called for at the factory level. 

The typical install - As LS swaps have become very popular, LS Swap gurus have figured out affordable ways to make the installs go as smoothly as possible. With that being said many people use a Corvette style regulator and combination unit. The Return less setup with the corvette style regulator is perfect for both in tank and in pump installs. 

Hot Rod fuel hose recommends an AN6 fuel line kit for this style of install. Using the proper fittings you can easily install from the tank, to regulator, to fuel rails and have an effective setup with minimal effort. Check out our LS swap kits for the easiest install options. 

In - Tank pump setups are very similar to in-line options with the exception that the pre-filter is a sock that fits on the inlet of the pump. You will still want to run a 30 (minimum) or 10 Micron (recommended) post pump filter. Once again the Corvette style regulator and filter is a common option for LS swaps. 

Check out our Return-Less LS swap kits here. 

Return Less LS Kits 

Setup B - Return style setups

Fuel pump options for AN line return style setups are the same as a return - less setup with the difference being that the fuel pressure regulator is built into the fuel rails themselves on the LS engine. You will need more hose on a return style setup as both the feed and the return line needs to return from the engine bay. AN LS stock fuel rail setup utilizes 3/8 inch quick connects on the feed and 5/16 quick connects on the return, both available from Hot Rod fuel hose LS swap kits. You will still need a filter before the fuel rails and you will want to ensure the correct fittings and pump are used for your install. 

Reach out to Hot Rod fuel hose to ensure you get everything that you need.

Our AN hose is great for LS swaps and gives a performance and upgraded look to any LS swap. Hot Rod fuel hose knows what it takes to deliver fuel to your LS swapped engine whether is be a C10, G body, later model chevy, or any type of car in between we can help with your LS swap needs and help you to deliver power to the road. 

Check out our Return Style LS kits here. 

Here is a collection of photos shared by our customers using, installing, and receiving our AN PTFE hose & AN fittings. Thanks for the support.

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