The Ultimate Guide to EFI Part 6 – being Ethanol safe & building a custom fuel line

As you go through the process of building a car it becomes a game of managing snowballs, and learning which snowballs to chase and which to dodge. While it can be tempting to slap a car back together and think “I’ll just get to that job later” the reality is there are some jobs that are better to do while everything is apart and you have the time to get it right. 

One of these jobs is replacing the fuel line. Originally, I’d intended to use the stock 3/8″ steel line to feed my custom EFI set-up. However, as I was planning on using E85 ethanol fuel at some point and still had to plumb a high-pressure EFI filter and flex-fuel sensor into the existing line I knew I was going to have to customise the set-up at some point.

This is what will carry fuel from the tank outlet (on the right) all the way to the injector rails (on left)

I was impressed at the quality and cost of the Raceworks fittings. I was using AN6 (-6) sized fittings and line as this will be plenty for my mild 400ci Pontiac V8. As I was using 200-series hose I needed matching 200-series fittings to suit, as the 100-series fittings are designed for ordinary-style fuel hose and the 400-series is for push-lok applications. 

The 200-series fittings have a small aluminium collar which locates in between the Teflon hose and the braided outside, and provides a locating surface for the fitting to seat down onto. The image below is a -6 200-series straight-fitting.

In the end I bit the bullet and bought 10 metres of 200-series Raceworks braided fuel line, along with a few hundred bucks’ worth of fittings. The 200-series hose is Teflon-coated so it doesn’t allow fuel smells to permeate the cabin.

After the fitting’s collar is slid onto the hose the metal collar is pushed over the end of the Teflon hose. This is then pushed down on a hard, flat surface to seat properly. 

The seated metal collar.

Here you can see how the hose end pulls down over the collar providing a leak-free clamped surface. 

The hose end of the fittings need to be lubricated with some car washing detergent to help them slide home and, because they’re made of aluminium, it helps prevent the threads galling as they’re wound together.

Yes, I’m a shadetree mechanic. You’re meant to use aluminium vice jaws for this job but several layers of masking tape in the vice will hold the fittings without scarring the soft aluminium. You need them held fast as you wind the hose over the barb as it is TOUGH.

Here is how a fitting looks, fully assembled. This is the 90-degree fitting which attaches to the end of the fuel rail set-up.


My fuel pump. fuel filter and flex-fuel sensor all run quick-disconnect fittings from new, so I needed to buy adapters to bridge the quick-disconnect barbs to AN-style fittings. Thankfully Raceworks sell these in a range of outlet positions, as I needed straight-fittings for the filter and flex-fuel sensor, but a 90-degree fitting for the fuel pump.

The white push-lock clips seat on a raised barb on these parts, and the aluminium fitting simply clips over the top. The following 3 images show how the fittings work and why they’ll be handy when this sensor is under the car (should I need to work on it).


The fuel filter is from a 2002 Holden Commodore SS (a cousin to the late-model Pontiac GTO), and cost a brutal $6. This part (and the flex-fuel sensor) will live in under the car tucked safely out of the way in the channel of the boxed chassis rail.


The pump will be accessed through the new, custom trunk floor, through a bolt-in hatch panel.


The full list of fittings required for my deadhead (single-line) fuel system is as follows: 

AN6 220-series straight hose ends x6 (RWF-201-06BK)

AN6 220-series 90-degree hose ends x2 (RWF-203-06BK)

AN6 220-series 60-degree hose end x1 (RWF-208-06BK)

AN6 male tee piece x1 (RWF-824-06BK)

AN6 to 3/8 quick-disconnect straight adapter x4 (RWF-715-06-06BK)

AN6 to 3/8 quick-disconnect 90-degree adapter x1 (RWF-812-06-06BK)

AN8 ORB-to-AN6 adapter x2  (RWF-920-06-08BK)

AN6 220-series braided hose x10m (RWH-220-06-10M)

While I used a barb fitting below I changed this when I decided to replace the entire fuel line and replace all joins with AN fittings.


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