Jump to content

effect of changing from 5/16 to 3/8 fuel line


desoto1939

Recommended Posts

Here is a question for the group. My fuel line is 5/16 OD. I am having an issue trying to get a 90 degree inverted flare fitting with the 5/16 tapered fitting on both angles. For some unknown reason these are not being stocked by any of the major hydraulics and fitting suppliers. I even walked Hershey last week and could not find any fitting.  They do have 1/4 and 3/8 fitting with the 90 degree flare inverted at NAPA.

So, the question that I am asking, Would there be any major fuel issue if I changed the 5/16 OD to a 3/8 OD line I am increasing the ID approx. maybe a 1/16.  Would there be any issue with to much fuel coming from the  pump to the carb in a volume issue.  I would not think so because the pump only puts out 3-5 lbs and the flaot also controls the amount of gas going into the carb bowl.

Any input would be appreciated.

When I have seen the 5/16 inverted flared 90 Degree fitting listed they are going for $13-15 each and if they are getting harder to find then lets go with a more common fitting and line since they are available and also cheaper.

All 25 cents worth of input if fine by me.

Rich Hartung   Desoto1939@aol.com   Cell 484-431-8157

Link to comment
Share on other sites

I had a similar problem when I installed my new fuel tank.  They said it was exactly the same as stock.  1/2" wider front to back and the fuel line fitting needed a longer male fitting to fit.  5/16" fuel line.  Everyone stocked the 1/4 long male but I had to pay $15 to order a 5/16ths one.  How many times do you think you will need to change fitting or replace the fuel line?  Seems to me it would be much cheaper to buy the 5/16ths fitting.   Good luck.

Link to comment
Share on other sites

3 hours ago, casper50 said:

I had a similar problem when I installed my new fuel tank.  They said it was exactly the same as stock.  1/2" wider front to back and the fuel line fitting needed a longer male fitting to fit.  5/16" fuel line.  Everyone stocked the 1/4 long male but I had to pay $15 to order a 5/16ths one.  How many times do you think you will need to change fitting or replace the fuel line?  Seems to me it would be much cheaper to buy the 5/16ths fitting.   Good luck.

Ditto.

Link to comment
Share on other sites

I searched Edelmann's catalog and couldn't find a 90degree fitting.  I did find a tee fitting with the inverted on all three and they do make a plug for the inverted as well.  It may be an ugly solution but it should work.

Link to comment
Share on other sites

To answer your question about fuel line size: if the outlet port size of the pump and the inlet port size at the carb remain the same there should be no difference in operation.  The only difference might be if you were to completely drain the fuel line it may take longer for the line to refill  if you had a larger size line.  As an extreme example lets assume the ports are 3/8 inch diameter.  If you were to increase the size of the tube to say 1 inch pipe and the output from the pump was 1 cubic inch per stroke then it would take more pump strokes to initially fill the pipe but once it was filled (since liquids are not compressible) one pump stroke input would result in one pump stroke output.

  • Like 1
Link to comment
Share on other sites

Good News.  I just found a Hydraulics supply warehouse in Philadelphia that stocks these 90 degree 5/16 inverted flare brass fittings.  The cost was $3.00 each so I ordered several of them to be shipped to my home.  I would like to thank everyone for their input on this topic.  The internet is great for finding stuff like these items. It surprise's me that even NAPA does not carry these fitting and this is a standard brake and fuel line size. I will update everyone on the project after getting the new fuel line installed

.Rich Hartung  Desoto1939@aol.com

Link to comment
Share on other sites

Common enough to have one inverted and the other end of the 90 degree in a standard pipe thread. I'd think it more common  to just bend the 90 in line itself.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use