I've dropped my tank and stock fuel lines out of the car this past weekend. I have a walbro 255 intank pump right now already in the tank. I am going to be running -8 AN line from my regulator to the tank for both my supply and return lines. I have a couple questions.

Does anyone have a picture on where you welded a fitting at the top of the tank for their return? Also, I know i should be using a steel fitting for the top of the tank. What's the fitting i should be looking for? Is it ok for the fuel to just dump in from the top of the tank on the return like this? I am not going to sump my tank. (I will run dual walbro pumps eventually)

Next thing, for the supply line I was thinking of leaving the factory 3/8" line coming off the stock pick-up / sending unit about 4". Then from there getting a fitting to go from the stock 3/8" line to an AN fitting. From the AN fitting I would put an addaptor then a -8 fitting on the other end to the fuel filter. This is the best way I can come up with doing this with the intank pump. What fitting would I need for the factory supply line to convert it over to AN?

Thanks in advance.

 

Anybody?

 

I run a 4th gen tank which has plastic snap-fit connections at the supply and return areas. I run dual intank walbros at the moment and what I did was stock plastic line snap-fit fitting to -6an then a -6an to 8an conversion fitting. 8 to the rails, and 8 back to the tank. Return line I cant remember if it was a custom fitting inserted into the top of the tank for 8an size or if it also did a 8 to 6an conversion fitting.

I'll look for my pictures later today. the way you describe the supply is probably the best way. I think these quick connect fittings I used can be used on the 3rd gen metal lines too.

 

Thanks for the reply. My return line will probably have to be drilled in the tank somewhere. I was wondering what fitting would be best to use for this? A link maybe? It would be -8. I was also trying to find an AN fitting that would bring the stock 3/8" line to an AN fitting? From there I'll get an adapter from 6 an to 8 an. Shouldn't really be to much of a restriction because I'll be only using the first 4" or so of the stock supply line. Right?

 

A higher pressure EFI type pump can supply ALOT of fuel through a -6 line. Late model vette and fbody guys have 3/8" supply lines I believe and have made near if not over 1000hp.

To take a hardline to AN, you'll need to flare it I believe and use the adapter fittings for that type flare.

BUT you may beable to do these crimp type tube/nut fittings
http://www.summitracing.com/parts/RUS-639200/

Suppose to work on tubing without flare tools. Something like that should work.

 

The link you posted was what I was thinking. This fitting says it's used for 3/8" aluminum tubing. Will this work with the factory steel line??? I really don't want it to fail and drop the tank again though. I have all the -8 line already and some assorted fittings. Do you know (or anyone you know of) if this style fitting from the hardline to AN is reliable? From there I could attach a -6 to -8 adapter and run my -8 line correct? Thats the way I'm picturing it to work now.

As for the return. I'm still unsure on what fitting I need to weld to the tank. Any ideas? Also, the best placement for the return fitting as well. Also, another question. I will be cutting off the existing return line and evap line about 3-4" off the sending unit and closing them up. (they won't be used) What's the best way to get those to seal?

Thanks for the help.

 

I'm curious about the line pressure myself but I got a feeling it will work just fine. Arent the stock rubber lines just sliipped over the steel tubes and use a clamp?? AN-tube fittings should clamp ALOT harder than that.

I used that type of fitting on a nitrous hardline and that holds 1000 psi but its aluminum tubing...I'm sure the steel line would hold 100psi fuel pressure

PM Lonnie P from Lonnies performance and ask him if he thinks you can get away with those fittings. He does fuel systems and did the dual in-tank setup on my car. Supplied me all the fittings i needed. He doesnt get on here as much as he should, atleast doesnt post as much.

As for the return, maybe a 90 deg AN fitting to hose barb, somehow "glue" or weld if you can find a steel fitting or if the tank cap is aluminum, weld fitting to that. Then attach abit of hose to the underside to return fuel to the bottom of the tank. I believe I have seen someone do that here along while ago. It may have been a DIY dual intank setup where they custom fit their own return line.

 

Thanks alot for the reply. I'm thinking more and more I'm going to be able to use that tubing adapter to the AN fitting. I seen the thread about the return line with a 90* bulkhead at the top. I was thinking about maybe welding some kind of fitting next to the filler neck? Not sure if the fuel has to go to the bottom of the tank or not though.

 

Weld the return to the front of the tank facing the engine side, not the side of the tank up by the filler neck IMO. Also I told you those aluminum crimp fittings will not work at efi pressures They will vibrate, fail and leak at high pressure, they are for 15psi and less IIRC

 

Yeah from abit more research, it seems that they will not work. I replied to your other thread, flare it or use a compression fitting with all kinds of adapters to get it to AN

 

honestly just run the larger return and leave the stock fuel line alone would be my opinion Since you can't find the compression fittings from the drag thread

 

Earls makes a compression AN-8 fitting that I have used a couple of times on steel line. I have talked to there tech line. It is rated to 50 psi, but the gy said they have seen many use it long term at higher pressures and I am experiencing the same results. It works. I have two Ls swaps that are driving around for 2 years now with these fitting. As for the original post. I am running AN-8 for return and feed. Probably not worth it but, here is what I did. I flares the tube coming out of the sending unit at the tank using the summit tool it worked fin and then I purchaed on of the AN bulkhead fittings you use on Fuel cells and used it on my stock tank, in the upper front passenger side corner, to keep from distrubing the fuel at the pickup. Been working for a couple years no problems I push a consistant 50 at part throttle and upwards of 63PSI at WOT.