Fuel hose size confusion

[djhammy]

HI ladies and gents confused of Southampton here.

Having read the following info on Volks bolts I'm now a tad unsure that putting 5.5mm hose on my pump is correct as i have always been lead to believe the O/D of the pump metal stand pipes is also 5.5mm. Same scenario applies for the 7mm hose that comes off the tank. Recently purchased a new pump from Brickwerks who say that mine is 5.5

http://www.volksbolts.com/faq/fuelhose.htm#Hose" onclick="window.open(this.href);return false;

Please see diagram in above link.

It is of EQUAL importance to select a hose with the correct inner bore diameter (I/D) as it is to select the correct hose grading.

One of the useful propertiers of rubber is that it has the ability to stretch - and to 'recoil' back to its original shape. The material essentially behaves like a mouldable Spring. This elastic spring force combined with the friction between the hose and the pipes generates 'Grip' that under normal operations will hold the hose in place (in a similar way that a rubber tyre grips the road).

The ability to stretch combined with the Grip generated is useful as this means we can get the rubber material to strech over the ends of metal pipes; providing its own seal as it 'recoils' and moulds itself to Grip the profile of the pipe. (Within the reasonable limitations of the material)

This is appropriately demonstrated in the picture below - based on the stock VW application of 5.5mm/5.6mm I/D bore hosing onto the 6mm O/D metal stand pipes of the fuel delivery system.

I have found a great fuel hose supplier in Southampton Hyperhose who sell ISO 7840 Hose. Alas the sizes are all imperial so guess 1/4 inch being the smallest is still to big for my pump.

http://www.hyphose.com/index.php?main_p ... ath=13_112" onclick="window.open(this.href);return false;

Cjeers

Dave

[Pootle]

I have just replaced the hose between the fuel pump and (Weber 34DAT) carb with 7.5mm bore fuel hose. I noticed that it was a tight fit on the carb but an easier fit on the fuel pump.

To make sure of a good seal I used proper fuel hose clips at each end and checked for no leaks with the engine running. You really don't want those pipes leaking.

[BOXY]

Ask the guys at Hyphose if they can supply Parker ITR fuel hose. They're a Parker distributor so should be able to get it in for you. It's made in Italy so comes in a full range of metric sizes. Tell them "Griff, ex-Rotec" said they'd supply it.

[djhammy]

HI Griff thats the stuff i did get nice one. Well i'm pretty sure it is.

http://www.hyphose.com/index.php?main_p ... cbe45ee0da" onclick="window.open(this.href);return false;

I also found out that a guy who's wedding i'm doing works there so even better.

Dave