Fuel Hose

[Neil-yaj396]

What size flexible hose are folks using? A search threw up reference to 5mm (bore) for the return pipe which seems a bit big to me, although I'm not convinced that the smaller pipe that I fitted recently (3mm?) is delivering sufficient flow. It is the mechanical pump to carb hose that I need to replace now.

I also seem to be bedeviled by the fitting clips not giving sufficient clamping, so any recommendations for those would also be welcome.

[Neil-yaj396]

Further browsing revealed that I asked this question in 2011 when I was replacing the hoses on YAJ!

8mm & 6mm were suggested, but I still think these are on the large side for my car in both instances.

[JohnFol]

When I fitted an electric fuel pump I used this stuff

https://www.amazon.co.uk/gp/product/B00XU8M2SM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Interestingly ID is 8mm and you are concerned 5mm might be too big..

[Nigel]

Hi Neil,

I used the full circumference clamp, I think from Car Builder, with the 3-4 mm screw.
Don't use jubilee type if you can avoid it.

These days hoses need to be ethanol-proof, and I don't read a mention of that in the
type that John got. I don't know the numbers to look out for though.

Nigel

[peteracs]

Hi All

I believe the recommended fuel hose are to R9 spec. I bought Coline branded hose for mine. It is recommended you buy a definite recognised brand as there are reported to be a older R6 hoses which have been relabelled and are not so tolerant of the latest ethanol mix.

This website gives you a wordy, but informative view on fuel hoses.

http://www.volksbolts.com/faq/fuelhose.htm

Peter

[Neil-yaj396]

When I fitted an electric fuel pump I used this stuff

https://www.amazon.co.uk/gp/product/B00XU8M2SM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Interestingly ID is 8mm and you are concerned 5mm might be too big..

Thanks John, 5mm is for the return, not the main pipe. Good suggestions from all on spec, but I'm still unclear on the bore sizes being used?

[smithymc]

I used Codan ethanol safe stuff. Its marked 7.9mm or 5/16” id.

Mark

[JohnFol]

Hi Nigel, it's not clear so I re-read the description of what I bought and cross referenced a few sites.
"SAE J30 R6 grade hosing for ethanol enriched E5 and E10 petrol."

So I think I'm ok

[peteracs]

Hi John

If the article I ref’d above is to be believed, the R6 standard was introduced way before the newer ethanol fuels were and there is a chart showing the relative permeability of R6 and R9 which is a 400:15 difference ie 26 times more permeable to modern fuels. That is not to say it is not safe, just if you have R6, keep a regular eye on it for weeping. If in doubt replace it of course.

Peter

[mangocrazy]

I did some research on this a few years ago and concluded that the fuel hose that's readily available in the UK is mainly not fit for purpose. If you look at the fuel hose available in the USA, where they have had ethanol in their petrol for far longer and at much higher concentrations, their fuel hose is way ahead of what we can routinely buy. Seven or eight years ago I obtained some Gates Barricade Greenshield hose, which had vanishingly low levels of permeability and was warranted safe against ethanol (all concentrations), methanol and heaven knows what else. Whereas we can buy fuel hose that conforms to R6 or R9 of the SAE J30 standard, Gates Barricade hose conforms to  R14 (T1), and has done for many years.

Thankfully it seems like this hose is now becoming available in the UK, if you look carefully, so if you can track any of it down I'd use it in preference to any other hose.

[JohnFol]

Beaulieu auto jumble is only a week away...

[Neil-yaj396]

Following this thread through can someone recommend a good pair of pipe cutters? I've used a serrated knife or junior hacksaw in the past but the new pipes that I've bought, and I'm taking this as a good sign, are noticeably tougher.

As I'm changing all the flexible pipes, front and back, I've plenty of cutting to do.

[peteracs]

Hi Neil

I just use Stanley type knife.

Peter

[WestonE]

Hi Neil

Avoid using a saw it can drop rubber crumbs into the pipe that end up blocking jets. A stanley or decent snap off blade knife works. Just make sure you keep using a SHARP blade.


Eric 

[mtulloch]

I use cable cutters like this

https://www.zoro.co.uk/shop/hand-tools/insulated-tools---pliers-and-cutters/00125-9%22-cable-cutter/p/ZT1199157X?utm_source=bing&utm_medium=shopping&utm_campaign=bs%2B%7C%2BHand%20Tools&utm_term=ZT1199157X&dev=c&utm_campaign=bs%20-%20hand%20tools%20%230&utm_medium=shopping&msclkid=7ca991c5361b1bd0c1ddf097013832ce&utm_source=bing&utm_prodid=ZT1199157Xtargetid

[Sandro]

While we're on the topic has anyone used or heard of Alfagomma fuel hoses ?

They're in stock at the local Auto parts place I purchase from and I wondered if anyone here has had any experience good or otherwise using this brand.
I've written to Alfagomma in the meantime to try to glean some more specific product information.

Thanks,

Andrew

   

[mangocrazy]

I think the very first question you should ask of any fuel hose vendor is 'what level of the SAE J30 specification does your hose conform to?'. The latest and highest level is (I believe) R14 T1. Anything less than this should elicit further questioning.

[peteracs]

Hi Graham

I have read some threads on R14 just to confuse where it is rated at a lower PSI than R9, so folk were less inclined to use for that application. It is mentioned here that R9 is for high pressure use, R14 is for low pressure.

http://www.volksbolts.com/faq/fuelhose.htm

I have no way of confirming this, but mentioned on more than one site.

Peter

[mangocrazy]

I wasn't aware of R14 being for low pressure use, but will check further. For carburetted cars that wouldn't be a problem, as max fuel pressure is of necessity very low. The Gates Barricade Greenshield hose for fuel-injected cars is safe up to 16 bar (235 psi). The hose sold for carb engines is safe up to 2.4 bar (35 psi). Both hose types are certified compliant with the SAE J30 R14 standard.

From what I can see, SAE J30 R14 T1 is for low-pressure hose with ultra-low permeability. The 16 bar Gates hose I referred to above is actually listed as SAE J30 R14 T2, so I suspect there are sub-types depending on whether low or high pressure use is required. The main point about R14 is that it is the standard for ultra-low permeation properties. This type of hose is typically approved for use with leaded and unleaded petrol, diesel, biodiesel, E85, methanol, ethanol and gasohol fuels.

So providing you match the hose type (T1 or T2) to the intended pressure application, I'd say go with R14 every time due to its exceptionally low permeability.

[peteracs]

Hi Graham

There was some mention of the R14 spec being related to low emissions requirement and not seen anything on type 2, so good call on differentiating the two types, good job it is only complicated. From what I can see R9 is also ok to use on ethanol, but not necessarily on some other fuels.

Peter