Safe to use LPG polypipe for fuel injection?

[rcx106]

As an easier alternative to copper, was thinking of using Faro polypipe, designed for use in LPG, as the main fuel injection feed on my Vitara. What do we think?

[stevieturbo]

rcx106 said:

As an easier alternative to copper, was thinking of using Faro polypipe, designed for use in LPG, as the main fuel injection feed on my Vitara. What do we think?

I'd have no issues about using nylon pipe, other than how you would secure each end.

[rcx106]

I've found nylon pipe that is pressure rated and also fuel resistent, but no fittings! Was going to use the LPG fittings, but they are designed for Faro brand tube which isn't nylon but some other semi rigid material.

[stevieturbo]

rcx106 said:

I've found nylon pipe that is pressure rated and also fuel resistent, but no fittings! Was going to use the LPG fittings, but they are designed for Faro brand tube which isn't nylon but some other semi rigid material.

Googling, the Faro fittings actually look quite good. They clamp and offer support for where it is clamped.

It should work ok.

I've seen people use pneumatic push type fittings before on nylon, I'd struggle to trust them on a fuel system for an engine though

OEM always press the nylon onto metal barbed fittings for the connections, or similar to that

[rcx106]

Will the nylon tube be good for bridging the gap between the chassis and the engine? Remembering that the engine is soft mounted so that bit of hose would be moving a lot.

[stevieturbo]

Some OEM will use nylon from pump to rails.

Obviously it will depend how you run the lines, but for most part I dont see why it wouldnt cope with engine movement.

[rcx106]

Stevie, I've just seen this video, it's pretty good because it gives you the standard that a tube must have to be fuel rated.

It shows the guy using regular hose tail fittings, heating the tube and pushing on. Super neat, easy, and easy to get fittings. Is this like the OEM way you mentioned?

https://www.youtube.com/watch?v=F6o-ZvLOQ7o

[stevieturbo]

I doubt OEM would heat the pipe, but they do force the nylon over barbs one way or another.

Bare in mind if he's using it for diesel it would be a low pressure application.

But yea, that video is describing a lot of good stuff on how they should be used, especially the metal insert to support tube if using compression fittings.

[rcx106]

I know about using Ferrules (inserts) that go into the tube when doing a compression fitting, god save anyone that doesn't use them, the joint won't hold.

So diesel is low pressure? My manual says that the EFI pressure on my Vitara is only 30 psi or so.

I'm going to use compression fittings on the main commie, and tails on the return and vent.

Thanks Stevie!

[stevieturbo]

rcx106 said:

I know about using Ferrules (inserts) that go into the tube when doing a compression fitting, god save anyone that doesn't use them, the joint won't hold.

So diesel is low pressure? My manual says that the EFI pressure on my Vitara is only 30 psi or so.

I'm going to use compression fittings on the main commie, and tails on the return and vent.

Thanks Stevie!

From tank to engine pump, diesels would all be low pressure. Some have pumps, but pretty sure none of those are efi pressures.

30psi is fairly low for efi, but possible, around 40-45psi is more the norm unless it was a single point injection which run lower.