Fuel Lines

[Pumpkin123]

I realise that this one has been done to death but I decided to look into replacing fuel lines this year so looking through previous threads it seemed logical to go down the kunifer pipe route. So I made up some kunifer pipes and fitted a ferrule on each end to stop rubber pipe falling off and everything was looking good. Only slight concern I have now is the normal rubber hose has an internal diameter of 8mm (5/16") and the kunifer I used was 8mm external diameter which obviously makes for a beautiful fit between the two but when I measured the internal diameter of the Kunifer it's approx 6.5mm so effectively reducing the internal cross sectional area of the fuel pipe by about a third. So I just wondered what size kunifer everyone else has used and whether anyone noticed any difference in performance. Any thoughts gratefully received as I can't seem to find any larger Kunifer pipe.

[mrzigazaga]

Hi

I had my fuel feed on the 350i replaced with the 8mm OD Kunifer copper, I think the internal diameters differ slightly among batches, I can see your thinking but I believe its all down to fuel pressure and not delivery, its under high pressure, 60 + psi or more so should be fine, I have not noticed any differences in performance etc..and only need to think about small sections of hose failing...


Hope this helps


Cheers

Ziga

[phillpot]

I believe it is quite normal to use 8mm (5/16") OD pipe, be it Kunifer or copper, it'll be fine.

[Pumpkin123]

OK Thanks for that, I will endeavour to fit them next sunny day.

I was slightly worried after spending ages making the Kunifer pipes that I was just going to end up taping them together and using them as a double barrel pea shooter.

Cheers