Efi Fuel Hose Sizes , And Standards .

[discopotato03]

Hi all , I've been having some dramas with fuel leaks on my R33 at the fuel filter . I was under the impression that these cars used 8mm or similarly sized high pressure hose but I don't think this is the case . When I started using Eflex E70 I changed the filter for a new Z201 and fitted new EFI hose as well . Long story short I kept smelling wafts of fuel and finding leaks on the lower side of the filter . Funny thing was sometimes it leaked and sometimes it didn't and no amount of tightening made a reliable fix . In the end I replaced the filter again and refitted the original I assume factory hose which is in reasonable condition - and doesn't bloody leak .

I did some research because I used to know of a workshop that stocked a large variety of low and high pressure fuel hose including 7.5mm . Wurth stuff I think it was .

It seems that Super Cheap advertise 7.5mm fuel hose which I'm going to look at later today and I'm taking the used filter and some of those nice Nissan style stainless clamps along too . One thing you ntice with the OE Nissan hose is that it has a smaller ID and OD and the std clamps struggle to get over the larger 8mm or 5/16" ID EFI hose .

Also , I remember reading here in the past that the in tank pumps EFI hose isn't the normal stuff and using regular EFI hose causes dramas . I found this link to a Gates page that quotes some SAE fuel hose standards and interestingly they talk about special linings for nastier fuels - like current low emissions stuff and ethanol . They ALSO mention that in tank pump hose needs to have the special lining on the inside AND outside to stop it swelling failing or whatever . It makes sense that hose manufacturers are not going to spend money on expensive outer linings for external hoses when its not needed but they have to when its exposed to fuel in a fuel tank .

http://www.gates.com/common/downloads/files/gates/brochure/techtipsform.pdf

Fuel hose has to be right for obvious reasons and it would be soul destroying to watch you car burn to the ground by the side of the road .

A .

[GTSBoy]

I don't know if outer linings are helpful for in tank installation. After all, you have two cut ends on each piece of hose, and outer coatings won't stop fuel penetrating the inner layers. Fuel hose for in tank applications is fundamentally fuel resistant, all the way through.

[GTR260]

I get my efi hose from pirtek, it's good quality & doesn't leak. The standard stainless Nissan clamps just fit over it

[simpletool]

From memory it is 7.5mm hose as you suspect, not 7.9mm or 8mm. I have sections of all sorts of hose in the garage, never know when I needed something and the R33 used to be my only car. I measured the pipe diameter of the fitting and it is smaller than 8mm, so I used 7.5mm hose.

[discopotato03]

I decided to stick my Verynear calipers on the just removed Ryco Z201 and was surprised to find its inlet tube is slightly smaller than the outlet tube .

The inlet side OD is ~ 7.91-2mm and the outlet is ` 8.00-8.02mm .

The box says made in China for GUD which looks like Ryco in Victoria ...

I wonder if this is a screw up on the manufacturers part or if genuine filters are like this too .

In my case these "Ryco" filters only leaked on the inlet side and the only difference is the tube diameters , it must be just enough not to allow the 5/16 hose to clamp up on though it always did on the cars steel tube side .

I think I'll start using genuine filters if the price isn't stupid .

A .

[discopotato03]

On the subject of filters people elsewhere are reporting start up rattles and anti drain back valves not working in "Ryco" oil filters .

I'm actually getting a bit of this and I remember thinking that the last Z145 I bought was remarkably cheap .

On site reckoned that Ryco Aust was trying to take their "supplier" to task over manufacturing faults with a number of fuel filters .

Does anyone have the part numbers handy for ECR33 oil and fuel filters ?

Cheers A .

[ARTZ]

just checking Disco but you did use proper fuel injection clamps ..not normal hose clamps..I got these for 1$ each at some speed shop...worth replacing..

just FYI i'm using Conan 5/16 hose...seems to work alright was cheap too

[battery]

just FYI i'm using Conan 5/16 hose...seems to work alright was cheap too

I use the same. For clamps I go down to the local pick a part and fill my pockets with old merc worm drive clamps they shit all over locally available shit and don't cut into the hose.

ryco Z200 fuel filter and nissan oil filter.

Edited December 4, 2012 by battery

[Missileman]

talking of hose clamps, how do these stack up?

http://www.ebay.com.au/itm/271017710915?var=570101545758&ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[battery]

range of adjustment is very small so make sure you get the exact right size with those things!

[GTRsean]

I don't know if outer linings are helpful for in tank installation. After all, you have two cut ends on each piece of hose, and outer coatings won't stop fuel penetrating the inner layers. Fuel hose for in tank applications is fundamentally fuel resistant, all the way through.

The hose in the fuel tank is a butyl rubber inner and outer, where normal EFI hose for outside of tank is butyl inner, nylon type crap outer and not fuel resistant.

Someone decided to use the nylon outer EFI hose in a fuel tank once, I changed a mates fuel pump and found crusty bits of fuel hose and pieces in the tank lol....

The fuel tank genuine stuff is like $120 a metre or so.

[discopotato03]

Yep I've always liked Nissan OE fuel line clamps , those narrow band Wormald style ones are a last resort .

The hose I had used was some American marked -7 5/16 stuff .

Going to check out Explosive Racing at Peakhurst tomorrow , cheers A .

And I will be measuring the barbs on the filters too .