other Gas Line Size Conversion

[1972-2002]

so the output line on my fuel pump is 6mm and the input on my carb (weber 38) is 8mm how do i get a line from one to the other? conversion nipple (is one made)? thoughts? Answers? HELP

 

Thanks in advance

 

Garry

['76mintgrün'02]

I was wondering about this a while back.  I learned that pumps are made this way to avoid cavitation.

Pump suction inlets are always larger than the discharge (even on large pumps of thousands of HP, I worked with pumps and pumping systems, in part, for 40years) so the fluid won't cavitate.

  It would be nice if they kept the smaller ID and made the OD match the input side.  I have considered making a new outlet like this for my pump.  One suggestion I got was to use smaller fuel line from the pump to the fuel filter and then larger leaving the filter and going to the carburetor.  All this can be found at the end of this thread. http://www.bmw2002faq.com/topic/148165-radiator-hose-interferes-with-new-fuel-pump/

Edited February 16, 2014 by '76Mintgrun'02

[tim385]

Dip the end of the 6mm hose in some hot water for a bit then push hard it should go on.(mine did)

[Stevenc22]

Yeah I just pushed my 6mm line onto the Weber.

[jimk]

If the Weber had been the stock carb, the nipple sizes would have been the same size.  The problem is with the doer when an aftermarket part is used.  Should be no complaints with BMW.

[1972-2002]

Jimk - i am wondering how your comments help me? Did I complain about BMW? I just wanted help, not a scolding from my mom!

 

Garry

[jimk]

This kind of a question deserved it!

[1972-2002]

Nice comeback - did you think of that one yourself!

[Hans]

Play nicely, boys and girls.

Try a universal plastic in line filter with different ends, or buy a reducer - I think Pierce has one.

[eurotrash]

I mentioned this once before, but when working on my car this past fall,  I noticed that the nipple on my carb'd 2002s pickup/sending unit is also 6mm.  But the hose at the tank connects tightly to the 8mm nylon feed line..  Upon closer inspection of the section of original cloth wrapped line I was replacing, I found that BMW inserted a bit of what appears to be the nylon tubing into pickup the end of the hose, thus stepping it down to fit tightly on the nipple of the sender/pickup..

 

Just an observation.

Edited February 18, 2014 by eurotrash

[Colin]

I mentioned this once before, but when working on my car this past fall,  I noticed that the nipple on my carb'd 2002s pickup/sending unit is also 6mm.  But the hose at the tank connects tightly to the 8mm nylon feed line..  Upon closer inspection of the section of original cloth wrapped line I was replacing, I found that BMW inserted a bit of what appears to be the nylon tubing into pickup the end of the hose, thus stepping it down to fit tightly on the nipple of the sender/pickup..

 

Just an observation.

This.

[Hans]

But I believe that plastic sleeve will not work on the fuel pump outlet if that's what you were suggesting. Easier to use the dual size fuel filter.