The answers and assistance offered by TGO members is invaluable. Thank you all.

I have a few more questions, some of which are just double checking specifics.

1. I'm using the corvette style fuel filter/regulator. I know for plumbing reasons it is often located near the gas tank. But does it pose a hazard if I mount it in the engine bay?
   • No, just keep it away from the exhaust
2. I understand that AN style fittings use a 37 degree flare. But should it be a single or double flare? Does it matter?
   • Single
   • Summit Racing 37 Degree Flare Tool: http://www.summitracing.com/parts/SUM-900311/
3. Is a rubber hose with worm clamp connection suitable for the barb style fitting shown below? Will it seal properly for fuel injection?
   
   • Not for the high pressure side, use fuel injection clamps, they have a real bolt on them. Worm clamps are just fine for the return though
4. I understand that -6AN means 3/8". So if I have a metal fuel line that is 3/8" OD, then a -6AN fitting size and -6AN hose size are both compatible with (and roughly equivalent to) this metal line?
   • Approx
   • An explanation also at the Holley Technical Library http://www.holley.com/TechService/Library.asp in the Thread Size Reference Guide http://www.holley.com/data/TechServi...ad%20Sizes.pdf
5. When using NPT fittings on a fuel line, is it recommended that the threads be sealed with something?
   • Teflon tape or paste. Same goes for anything that requires a good seal and NPT threads
6. Are AN fittings from Earl's and AN fittings from other manufacturers interchangeable?
   • More or less. Just dont mix and match piece of each fitting, like a sleeve and a nut from different mfrs. A russel -6 hose end will fit aeromotive -6 hose etc. This only applies to same style hose/fittings, as in a braided SS hose end will not work with a push-lock hose. All -6 hose has the same ID and approx same OD, AN threads are cut the same regardless of MFR, etc
7. Is it bad to attach aluminum fittings to brass ones? Like NPT connections?
   • If its something like a brass fitting in an aluminum intake or steel fitting to AN socket, it will be fine. Torque to the weakest material, usually aluminum which is just above snug
   • OEM uses bare alum trans case, brass fittings to mild steel lines without coatings and they dont have any issues over the life expectancy of the car with corrosion. Dissimilar metals DO corrode overtime but the level of corrosion isnt enough to matter for a car, esp for fuel and trans fluid systems
8. I have a barbed connection that will be getting Fuel Injection rated fuel line attached with Fuel Injection hose clamps. I'd prefer to use steel braided line like Russell's Pro-flex. Can steel braided line be connected to a barb fitting with the Fuel Injection hose clamps?
   • Its not recommended but people do it anyways
   • https://www.thirdgen.org/forums/fabr...se-clamps.html
   • http://forums.corvetteforum.com/c3-t...se-to-use.html
9. Should teflon tape or any type of thread sealant be used on normal AN fitting connections?
   • No, a drop of oil to lube the threads is all you need

 

1: No, just keep it away from the exhaust

2: Single

3: Not for the high pressure side, use fuel injection clamps, they have a real bolt on them. Worm clamps are just fine for the return though

4: Approx

5: Teflon tape or paste. Same goes for anything that requires a good seal and NPT threads

6: More or less. Just dont mix and match piece of each fitting, like a sleeve and a nut from different mfrs. A russel -6 hose end will fit aeromotive -6 hose etc. This only applies to same style hose/fittings, as in a braided SS hose end will not work with a push-lock hose. All -6 hose has the same ID and approx same OD, AN threads are cut the same regardless of MFR, etc

 

Thanks Pocket! (again!)

Pocket has been super helpful on many topics.

 

7. Is it bad to attach aluminum fittings to brass ones? Like NPT connections?

8. I have a barbed connection that will be getting Fuel Injection rated fuel line attached with Fuel Injection hose clamps. I'd prefer to use steel braided line like Russell's Pro-flex. Can steel braided line be connected to a barb fitting with the Fuel Injection hose clamps?

 

Anyone have tips on questions 7 & 8 above?

Thanks!

 

9. Should teflon tape or any type of thread sealant be used on normal AN fitting connections?

 

out of curiosity, where and how are you planning to use barb fittings?

 

Well, funny story...

Actually I got a trick flow electric fuel pump, external, and it has a 5/16" hose barb off each end. To splice it into my hard fuel line I am running about 2 inches of fuel injection hose off the inlet and outlet to barbed brass NPT fittings, then adapting the NPT fittings back to the hard 3/8" stock metal fuel line.

I really wish I had selected a fuel pump with 3/8" inlet/outlet.

 

7: If its something like a brass fitting in an aluminum intake or steel fitting to AN socket, it will be fine. Torque to the weakest material, usually aluminum which is just above snug

8: Its not recommended but people do it anyways

9: No, a drop of oil to lube the threads is all you need

 

Thanks again Pocket!

You've been more valuable to this swap than all the tools in my garage.

Regarding Aluminum/brass combos, how about an aluminum AN/NPT fitting into a brass NPT fitting? Is this kind of mix & match ill-advised?

 

What i mean by mix and match is the individual pieces of a fitting can be taken off. Its not advised to switch these pieces around with different brand or material pieces

 

Ok, great, thanks.

I had planned some fittings where I would put a brass barb-NPT fitting to an aluminum AN-NPT fitting, but a parts-counter-guy (for whom I have less respect with each visit) said that you couldn't put aluminum and brass together.

This is all to accommodate the ill-advised fuel pump I chose. The 5/16" inlet/outlet is just not a fun size to work with. Learn by doing I guess.

Thanks again!

D

 

OEM uses bare alum trans case, brass fittings to mild steel lines without coatings and they dont have any issues over the life expectancy of the car with corrosion. Dissimilar metals DO corrode overtime but the level of corrosion isnt enough to matter for a car, esp for fuel and trans fluid systems

See if the pump has removable ends, that way you can unscrew the barb fitting and put a NPT (or whatever the thread is) to AN6 like the rest of the system. Alternatively you can buy a different pump instead of coughing up quite a bit extra to contend with what you've already got

FWIW, 5/16" is a common size for pumps, IIRC even the common walbro 255 uses this. Id still step it up to 3/8" or AN6 if possible. 5/16" is AN5, which is extremely hard to come by

 

Thanks for all this info. The pump does have a removable fitting, but only on the intake side, not the pressure side that I'm more concerned with. But I have puzzled it out and cobbled some stuff together for now. I may revisit the issue once I see how everything is performing.

Glad to hear that 5/16" is common. I thought I just managed to find the hardest option. Now that I have increased my fuel plumbing knowledge ten fold I'll be better equipped to take another look at it.

In case I forgot to say it before... Thanks Pocket!