hans14914

While working on the lower intake project I found I really wasnt happy with any of the existing fuel rail extrusions out there. So, I am going to have my own extruded. While there are lots of existing -6 and -8 options, none of them are really suited to my needs. There are some nice unique options worth considering when designing an new extrusion, such as the Extrudabody rail that has the built-in T-slot for fasteners:


http://www.extrudabody.com/servlet/t...gh-Flow/Detail

or the Viper Performance rails with multiple flat areas for enhanced mounting options:


http://www.viperperformance.co.uk/pr...hp?xscId=10031

I really like the overall design concept of the Extrudabody system, but it wont work for my vertical application, as it was designed for a 45degree injector angle for use with their ITB system.

I am contemplating an extrusion with a slot compatible with the 80/20 20-series hardware, which would allow the use of M3, M4, and M5 threaded inserts positioned anywhere along the rail for mounting harness clamps, rail hold-downs, injector clips, or cosmetic covers.

http://www.8020.net

The advantage of having a continuous track along the rail would be universal injector hold-down clips, that you could position anywhere you wanted. For a custom rail, drill the injector bung, and your clip is done, just slide in the nut, slip the clamp over the injector groove, and screw in the retention clip fastener.

As part of this project, I have already found a drop-in fuel pressure damper which is installed like a fuel injector from the bottom of the rail. It is held in the same way, with an o-ring and retention clip. It is compatible with modern fuel and additives, and manufactured by Bosch as an OE component. I also have a fuel pressure regulator housing designed that would accept a Bosch regulator and not use any threaded connection, but a sealed o-ring connection.

I will post some renderings of a tentative rail cross-section here shortly, but wanted to get some outside feedback on design before finalizing anything.

I think that the first extrusion would be -8 compatible, but open to feedback on bore/line size as well.

Thanks
Hans

Ducman82

i think -8 would be a great size. you can use -6 if you don't need the large amount of fuel, but have the -8 rails incase you boost etc.

mounting options are for sure, the big issue. i like the extruded/rail combo idea, but for up/down injectors.

hans14914

So here is a quick mockup of a double slotted -8 fuel rail. I have profiles drawn for both -6 and -8 in single and double slots.

This model shows the compact drop-in damper on the rail, as well as clips to hold the components. An system like this would allow for very quick customization of a fuel rail, and maintain all the safety features developed by the OEMs.

A 3D PDF is included of the quick model.

Thanks
Hans

victor25

Hans
Good idea Hans, I like that better than the slotted fuel rail above. We could do some good stuff with this if you had injector retaining clips to go them. In my first few installs, I used non-slotted aftermarket aluminum rails, but I just did not feel good with not having retainer clips on the injectors. I also ran into issues with not having adequate dampers to eliminate a thumping sound through the fuel line. This was caused by the batch firing injectors. It sounded like a rod knock at idle and low rpm.

btw... I think you only need a slot on 1 side

hans14914

Victor,

You may be right about just one slot. I can see an advantage to both, as it may be necessary to put the hold-down for the rail on the other side. I was also thinking about designing a wire loom clip to try and keep the the injector harness tidy. The clips would have to be inserted from the opposite side of the rail as the connector, so the harness clip idea wouldn't work if the slot wasn't on both sides.

In either case, I have both drawn up. I think I am going to reduce the width a bit. I may also look at a bit taller rail and creating a custom injector drilling bit to try and reduce the width even more. the injector bore is around 13.65mm so there needs to be some meat between that bore, and the slot. The actual injector feed itself is only around 5mm and 6mm for the damper, so a stepped tool that would only bore the 13.65mm for ~13mm or so, and then drill a 6mm hole all the way through to rail would be ideal, and allow me to shift the threaded inserts up and in creating a much skinnier albeit taller rail. Going to work on that later tonight to see how I like it.

victor25

A bit like this? This is the one I bought for my rails, and it is all the correct measurments.
You can borrow mine if you need it

jcorenman

Hans, think about thermal mass, and restarts after parking a hot engine for a while. I don't think the mounting slots are a good idea. My suggestion is to limit the rail to only what is needed for fuel and injectors, and have the mounting details welded on.

Cheers, Jim

GregBBRD

There's a thread that has been brought back up that is talking about "high volume" fuel rails and fuel line components.

I'd suggest you start there.