Fuel line dilemma

[BlackLC2burd]

Need some fuel system advice here guys. Doing a swap in my 1968 firebird which was setup for a high horsepower carburated big block. My question is this, I have a fuel cell in the car already with -8an feeds and have purchased an external pump, lines, filters, and fittings already. I have changed my mind and decided to go the sleeper route (the look of a sumped tank just screams out race car to me). So, I recently picked up an 87 fuel tank and 340 walbro for a good deal . My question is this, Will there be any downsides (fuel pressure issues, volume issues, etc.) to adapting the factory tank lines to -8an lines feed and return? Maybe a -6an return. I know the feed line from the factory hanger is restricted so i won't be able to use the full benefit of the bigger line, im just wondering if I can use what I have. The engine is all stock and will never see more than 21-23lbs of boost on 91/alky. I do have 50lb msd injectors and accufab regulator on stock fuel rail if that helps. Thanks.

 

[GNTurboTommy]

Racetronix sells a pick up with the 8an installed. (their on sale for around 125. in the vendors special forum) nice got mine in the mail yesterday. really nice quality made

 

[turbofabricator]

Simply silver solder, braze, weld on a -8AN fitting on the outlet of the pump and a -6AN on the return. Very simple to do. I do it often. Any wel stocked hydraulic shop will have weld on JIC -8 and -6 fittings in mild steel. I prefere to use silver solder as it seals well and melts at a lower temp than brazing rod. Might want to re-solder (regular acid core solder) the steel lines to the hat as they sometimes crack. If you can't find a weld fitting local. you can order tham on-line here: JEGS Steel AN & NPT Weld Fittings - JEGS They also make aluminum compression to AN adaptors available from JEGS, too. Though I'm not sure they are rated for 70 PSI??

 

[BlackLC2burd]

Sounds easy enough. Thanks Ken. Also , do you think the restriction at the bend of the outlet of the hanger will cause any volume or pressure issues for my application? Or should I change the feed line to 1/2? The racetronix hanger is a real nice piece, but i was trying to use what I have since i cannot return them anymore. Thanks guys

 

[BlackLC2burd]

Ok, somebody correct me if i'm wrong but I have been doing some more reading and from what I have found, the only restrictions in the fuel system are at the fittings on the rail and regulator, and not at the fuel hanger bends. I think I have misread something from before.

 

[turbofabricator]

The stock 3/8" sending unit outlet is capable of supporting a high 9 second run. Faster than that........dunno?

 

[Ttype6]

The stock 3/8" sending unit outlet is capable of supporting a high 9 second run. Faster than that........dunno?

The biggest restriction in the fuel delivery line is the fuel filter,but if you have an AC Delco filter you're not even close to its limit. The next restriction is the areas in the feed line where there are O-rings. There are four of them. One at the entrance and exit of the fuel filter,one where the line (sticking out of the font of the frame) connects to the flexible hose that goes to the fuel rail,and one where the delivery line connects to the fuel rail. You can drill these out. The return line is a non issue.

 

[BlackLC2burd]

Exactly what I was looking for ttype6. The stock hanger should be fine for what I'm doing. Thanks alot guys.