Fuel System Install Part 1 – Rear Soft Lines and In-Tank Fuel Pump

A little while ago, it was decided that the Boss would get fuel injection.  However, the intent in the whole plan was to make the injection system as “minimalistic” in appearance as possible.  In other words, when the hood is raised, the intent is that the engine bay carries “the look” of a modified engine bay belonging to a Boss 302.

Until rather recently, there were no throttle body injection systems that quite fit the bill.  But now, the market has almost exploded with very reasonably priced and well-rounded systems that satisfy “the look” as well as the functionality and convenience of modern fuel injection.

Since our path is determined, the time had come to start configuring the fuel system to support a sporty fuel injected engine combination, while maintaining “the look” as much as possible all over the car.  I admit, I’ve always wanted people to have to really work to take in all of the details of this build (and there are/will be THOUSANDS), with some being relatively obvious and clearly drawing attention while many others lurk in your subconscious before your eye recognizes them.

For a long time, I have been a fan of Aeromotive fuel system components, so it was a natural fit that we would choose their Phantom 340 Stealth in-tank fuel pump system as our go-to combination.  This kit is of exceptional quality and installation is relatively straight forward.  However, the entire system would require quite a lot of plumbing and careful component selection to ensure peak performance and longevity in a clean and unassuming package.  So, that’s where we started.

First on the agenda was to select proper fuel line materials and fittings along with a routing path that worked well the full length of the floor to the engine bay.  For fuel line, the first reaction by many is to install the venerable braided stainless lines with AN fittings.  While the AN fittings are more than adequate, the typical braided stainless fuel line isn’t really optimum for modern injection systems and fuels. 

The biggest problem with typical rubber AN lines is they essentially out gas fuel vapor over their lifetime at a fairly high rate (about 1 gallon fuel loss per foot of -06 hose per year!).  The two solutions are a Teflon lined AN hose or a modern rubber fuel injection hose like Gates Barricade.  With the Gates product, fuel vapor loss is eliminated and the flexibility and ease use makes it a perfect candidate for a modern hot rod when trying to keep the appearance subtle.  And best of all, the availability of push-on AN fittings like the Aeroquip AQP Socketless fittings makes this system capable of satisfying all of our needs in a simple package.

Another consideration is that running flexible AN lines for the length of the car makes for a difficult routing job and makes cleanliness an even tougher objective.  In our case, the soft lines are exclusive to the front and rear zones of the car with the connection between them (and the longest runs) taken up by the use of “Cunifer” metal hard lines.  Cunifer lines are among the very finest available and are an alloy of copper (Cu), nickel (Ni) and iron (Fe) in a 60/20/20% typical composition respectively.  They are highly resistant to corrosion, bend and flare beautifully, and are most often found in brake lines on higher-end performance and racing cars all over the world.

Our fuel system would be a combination of soft and hard lines beginning in the trunk and ending in the engine bay.  The first order of business was to carefully plan the entire feed and return circuit route from front to back and measure and sketch the plan making notes on component placement, bend locations, fittings required and component clearance.  At the same time, we needed to make sure the entire system was easily accessible and serviceable anywhere the car would be driven.

 

With our line plan established, we set off to plumbing the soft lines at the rear of the car.  This began with installation of the bulkhead fittings exiting the trunk area on the right side of the car as well as installing the mating fittings at the front of the car in the engine bay.  This established our absolute “pierce points” at the front and back and we could now easily visualize the start and end of our under-car fuel system.

Next, we mounted the Aeromotive 10-micron fuel filter and bracket in its predetermined spot, inboard of the rear sub frame.  The filter is, of course, another pair of absolute hard points and needed to be permanently positions to allow accurate routing of the soft lines in and out.

With the hard points now finalized, we began fabricating the rear soft lines starting at the rear and working forward to the filter.  I like to install an AN fitting in the free end of the hose and mount it to the bulkhead fitting so it is a stable and easy reference while routing the rest of the line in the most optimum way.  This acts as a “third hand” in a way and makes routing so much easier.

Once the feed line route to the filter is finalized, I cut the line about a foot longer than required and move to the return line.  The return line is routed it along the same path, and the line is cut at the same length as the feed line to ensure we can match the fitting locations as they join the chassis hard lines that we will make later on.

To aid in securing the lines and maintaining the proper routing, we used a few aluminum line clamps that secure and separate the feed and return soft lines and allow them to be mounted to the chassis in a very clean way.

With the rear soft lines in place, it was time to address the installation of the Aeromotive in-tank fuel pump system.  This kit is a rather amazing piece of business that allows almost any original muscle car fuel tank to be converted to a modern, in-tank electric fuel pump module in an evening.  The process, in fact, is pretty straight forward, with the most critical and complicated event being that of properly positioning and cutting the hole in the top of the tank for the pump mount.  Once the hole is cut to the proper 3.25” diameter, a nifty positioning ring is used to establish the drill pattern for the 10 mounting studs to pass through the top of the tank from the inside stud flange out.

Deburring the fresh holes is going to be a challenge, especially if you have ham fists like mine and can barely get a paw down the hole to try to access the drilled holes from inside.  A skinny, malnourished, but enthusiastic helper will go a long way in this endeavor for little more investment that a few pops and a box of Band-Aids.

Next, it is best to vacuum out as much of the chips and debris from the tank as possible followed by a thorough washing with a solution of simple green and water.  This will do a very good job of getting all of the metallic dust and schmutz out of the tank so no future damage to the pump will occur.  Of course, the tank should be dried completely before installing the pump module components.

With the tank modifications complete and the inside washed and dried, the foam and ballistic rubber “basket” can be trimmed to fit the tank depth (plus 1 inch).  Once that is complete, and with the help of the pattern fixture, the basket can be inserted into the tank.  The compression on the foam will act to help retain the stud ring and make the rest of the installation much easier.  With that, the hardest part of the installation is over!

At this point, the pump hanger is measured and trimmed to make the pump module overall length a match to the tank depth and the module is assembled as a unit for the final time.  Next, the pump flange gasket is placed over the mounting studs and the pump module is lowered into the foam basket and secured to the studs with the sealing washers and lock nuts provided in the kit.

While this is a bit of an oversimplified account, the project is certainly worth the effort and all of the included hardware is of the finest quality.  The remaining electrical connectors and wiring terminal boots will be saved for the wiring project later on, but for now, the tank is complete and we will move on to mounting it in the chassis and finishing the soft lines in the trunk area.

From here, we will move on to fabricating the front soft lines and finish it up by fabricating the hard lines to connect the works together.  Look for Part 2 soon!

We start by laying out the position of each AN bulkhead fitting so the fuel line "end-points" can be established. 

With the hole positions established, the centers are marked and pilot drilled.

 

A Uni-Bit is the best tool to open up nice clean holes in sheet metal.  Here, the second bulkhead fitting hole is drilled in the right side trunk area.

With the bulkhead fittings in place, the trunk fittings look especially clean.  The silver-white washers are actually Earl's Stat-O-Seal washers that provide a weather tight seal to the fittings.

On the opposite side of the trunk floor, the feed and return line end point fittings are put into place to ensure proper fit.

 

The front engine bay apron bulkhead fittings are next and install in exactly the same way as the trunk fittings.

From inside the engine bay, the feed and return fittings are very unassuming and tidy.

The final "hard point" element is the 10-micron fuel filter and bracket.  Here we have mounted the assembly in a secure location just inside of the right rear sub frame.

Using Gates Barricade fuel injection hose, we plumb the soft lines at the rear of the car by anchoring the rear trunk fittings first.  This acts as a "third hand" when routing the fuel lines by maintaining a firm anchor to the ends of each line, allowing full freedom to route the lines in the best possible way without a bundle of snakes coiling up behind you as you go.

Here are the soft lines for the feed and return circuits completed.  Notice there are a minimal number of fittings and no severe bends of disruptions in the line routing.  Smooth is good!

Here is an awesome little tip.  This is an Oetiker clamp (often called an ear clamp).  I use these extensively on high pressure fluid lines as they do not damage the rubber jacket of the line and they clamp very snugly around the entire circumference of the line.  These make worm-screw clamps look like something less than civilized.

Here are the aluminum line separator clamps I use when routing fluid hoses.  Th bolt in the center is modified to no only close the clamp but to mount it to the chassis as well.

Fuel pump installation begins by carefully positioning and then drilling the 3 1/4" hole in the top of the tank that allows the pump module to pass through. 

With the hole cut, the painful deburring process can begin.  The large hole is by far the easiest to deburr.  The whole game changes when the smaller mounting stud holes are drilled.......

 

This clever pattern fixture is included in the kit and helps to position the flange mounting holes as well as aid in the installation of the pump basket later on.

 

With the mounting hole pattern carefully mapped, the fixture is used to drill the 10 mounting holes required.  Once that is done, its best to kidnap a skinny car enthusiast that need money to reach in and deburr the holes for you.  Trust me, it's worth the investment in Band-Aids, smokes, beers, booty or whatever, 'cuz you WILL get cut otherwise.  Get it?

Once ll of the drilling and deburring work is complete,. the tank is thoroughly vacuumed out and then washed with Simple Green and water to get all of the remaining crap out.

 

With the tank depth accurately measured, the filter basket foam is marked and cut to size.  The foam is always cut 1 inch LONGER than the measured tank depth to ensure proper fit.

 

The interior stud ring ins placed inside the tank and held in place by the pattern fixture.  Notice the smooth funnel shape the fixture has?  This will make installing the foam basket a piece of cake shortly.

And just like that, the foam basket in inserted into the tank and the compression against the bottom of the mounting stud ring inside is enough to keep it in place during the rest of the install.

Here's a little detail that is not mentioned in the instructions:  This little dust cap must be removed from the pump inlet and outlet before the pump can be installed.  very easy to overlook if you don't know what to look for.

 

With the pump hanger bracket measured and trimmed to fit, the pump assembly is mounted to match the tank depth and the entire assembly is lowered into the tank over the thick foam sealing gasket and mounting studs.

The nuts and sealing washers are snugged up around the mounting flange and the installation is done!  The finished product looks mighty impressive and will support our fuel injection system with ease.

   

Here's a clever shot of the fuel pump module and foam basket mounted in the tank.  You can see the basket is flush with the bottom of the tank floor and doesn't interfere with any feature inside the tank.  With the exception of the small tuft of paper towel fluff I deposited into the tank just prior to this picture, the tank is clean and ready for battle.  Thank God for Shop-Vacs!

Doing a little plumbing on the Boss tonight!  Got all of the bulkhead fittings in place and line routing mapped for the hard and soft lines.  The car  will be injected so we have a feed and return line we will need to route from the tank to the engine bay.

Cleanliness is the name of the game and all fittings will be Aeroquip Socketless black anodized everywhere.  Next step is a nifty Aeromotive Phantom 340 Stealth in-tank fuel pump module and 10-micron post-pump filter.  More to come!

Out of the Shadows and into a New Shop – Rear 4-Link Suspension Installed!

At long last, I am extremely happy to say we are fully up and running in our new shop and FINALLY back to work on the Boss 302 project in earnest.  But before we cover the latest progress on the Boss, a quick overview of the last year or so in in order.

As many of you know, several circumstances and events of the last 2 years have conspired to consume most (ok…..almost ALL) of the time that would normally be dedicated to the ongoing build of our custom 1970 Boss 302 Mustang.  The domino effect began with the untimely passing of my uncle in April of 2014 from the ravages of cancers brought on by exposure to Agent Orange during his service in Viet Nam in the late 60’s.  This event required a rather sudden re-evaluation of just about everything going on in our home and existing work space to be able to accommodate the enormous amount of his belongings that were left to me on his passing.  Most significant in this was his prized 1932 Ford 5-window coupe; a Henry steel, real-deal gem that was a fixture in our home town in deep southern Texas since some time back in the late 40’s to early 50’s when my dad and uncle were youngsters.

Suddenly, the undeniable need for a new work space became the absolute priority and the only way we were going to be able to afford it was to build it ourselves.  Particularly since I had a lot of unique and otherwise rather costly features I wanted to incorporate along with construction details I was unwilling to compromise as well. So, in the summer of 2015, we began the long process of constructing a new shop to accommodate everything we needed and to provide a comfortable, albeit still undersized, work area that could now be dedicated to the current and future car building endeavors.

All told my dad and I, with the help a small handful of wonderful friends, my two son-in-law’s, and a few excellent pros, the structure was completed in about 4 months with the remaining interior finish work and details taking an additional 6 months or so to get everything “move-in” ready by our April 2016 deadline.

As April 2016 came, my good friend Bob (a true friend and soldier!) and I made the trip to East Texas to pull off a marathon 3-day pack-‘n-load effort (with amazing help from Gay, Midge, Jesse, & Jim!), of all of my Uncle’s wares and “The Coupe”.  With everything road-ready, we made our way back to Michigan with everything and ourselves in one piece.

The next four months were spent sorting EVERYTHING and putting things in their respective places so we could see the beautiful new floor again!  This felt like just about as much work as building the shop in the first place!  But, with perseverance, everything found its place and we were able to move the remaining cars and parts into the shop for the last time.  A few remaining smaller projects were completed to add a bit more functionality to the space and we found ourselves well into November 2016, and the first opportunity to actually refocus on car building in a year.  So there you have it……..the short version!

The "storage" side of the new shop..........already FULL!

This was a GOOD day!  The Boss project finally makes it's way into the new shop and a space all its own!  Still a good bit of clean-up needed in this shot, but that was completed shortly after this picture was taken.

Installing the Rear 4-Link Suspension Assembly

Getting back into the swing of things was a welcome and relatively painless process.  Funny how it always seems to work that way when you LOVE what you’re doing!

The rear axle and suspension had been essentially finished quite some time ago with only a few small details remaining to wrap up before it was ready to install.  First, I didn’t like the configuration of the brake “hard” line on the axle and decided to make a new one before the axle could go under the car.  I have gotten rather picky about hard line plumbing and while the first line looked plenty passable, it just wasn’t providing the “look” I wanted, so there was no choice but to scrap it and make a new one.

Once the brake plumbing was to spec, I installed the new rear brake calipers and brackets, along with fresh brake pads to round out the entire assembly.  At this point, there was nothing left but to install the entire works in the car and see how it all looked!

With the new hard line fabricated and in place and the new calipers and brackets installed, the axle was loaded on the cart and rolled under the car, ready to be lifted into place and hung in the chassis.

Installation was rather easy given the fact that, by this time, I had assembled and disassembled this system roughly a dozen times in fabrication and mock-up, so there was little doubt everything would drop it with little fanfare.  And so it was; everything installed with little conflict and in the course of a few hours, the axle was centered in the chassis and in the wheel openings (a nice bonus feature of a fully adjustable rear suspension!). 

 

A shot of the right side panhard mount and coilover.  Everything really looks tidy and business-like.

Left side coilover and panhard mounting detail.

 With the rear axle/suspension installed, the next dilemma was getting the car on some sort of temporary wheel/tire setup to allow it to remain mobile.  The challenge in this is that the Cobra front and rear brake combination severely limits the choices in spare wheels that will physically fir over the brakes.  It didn’t take long to see that factory Cobra or Bullitt Mustang spares are quite desirable and expensive, making them effectively a non-starter for shop use.  However, after considerable research and with the help of a very sharp gent at the local U-Pull-&-Save parts yard, we collected four pristine examples of 18” spares from later model, full sized Ford sedans (500, Taurus, Montego, Sable………you know, the ugly ones) and Freestyle crossovers which share the same 5 x 4.5” bolt pattern as the Mustang and have plenty of room for the big brakes.  For the cool sum of a whopping $11 each, we carted them home and the first pair of the set were bolted up to the flanges and we were set to go.

Cobra brakes (and larger) present some significant challenges when it comes to having temporary wheels that fit to roll around the shop.  Most are simply too small in inner diameter to fit over the brakes and the OEM Cobra and Bullitt spares command exorbitant dollars for this purpose.

Thanks to some diligent research and some excellent help from a local parts yard expert, we found a set of these 18" spares we harvested from later model Ford full-sized sedans.  Problem solved for the ripe sum of $11 bucks each!

So, for our first shot of work in our new space, we certainly didn’t move any mountains but I swear the earth moved when the last of the bolts was drawn up and the rear suspension was there for all to admire in its proper environment.  I’ve missed this work terribly and fortunately, we are well on our way to many more significant updates.

In the meantime, I wanted to extend a heartfelt thanks to all of the many supporters and enthusiasts who have stuck with us through this unusual period of non-car-related activity and your unwavering support and encouragement is appreciated more than I could ever express.  You folks are what make this community so incredible!

Sven