Technical Aluminum Fuel tank questions

I want to modify my dual aluminum fuel tank(s) on my cabover to allow me to run in-tank fuel pumps for Throttle body Fuel Injection on my 406 SBC.

I have some Questions.

1. Is there an inexpensive way to mount pumps into the tanks?
2. Who supplies various flanges that I can weld onto the tank and use to mount the pumps?
3. How do I isolate the tank from the steel mounting surface?
4. Can I drill and tap the 1/8" aluminum so that it will hold a bolt on flange? (is it thick enough)
5. Does anyone sell a weld in flange to use factory GM style pump pickups with the twist ring?
6. How big should the internal tray be...and how big for the drain/fill hole on the end?

Any other advice anyone can offer? Thanks in advance.

 

"Tanks" has everything you need.

 

need to know the shape and how your going to attach it ( side saddle , in frame rail , off frame rail , underslung )

1st thing , the fuel tank should be 3/16ths minimum for aluminum specailly if its outside the frame rail

as for pumps you can put a factory style pump in there off a bracket , the best design I have seen to date is a 4th Gen F body as it has a catch cup for the fuel to keep the pump covered at all times .( running the pump dry for a few seconds is the killer on these as it cools and lubes the pump )

for a acess , no gm tank is aluminum they are steel or polys ,
if you want copy the aircraft style ring and adapt it to hold the GM style pump assy in place the inner tank ring is 2 peice or weld it in place as a doubler to bolt the top ring too

as for mounting a pump in tank look at the 4th gen firebird set up as it will give you alot of ideas ,
http://chevythunder.com/LS1_fuel_pump_assemby.jpg ( image is large )

being immersed they are quiet , the pump stays cool and will last longer ( running a intank style pump dry for a second or two is what kills them not the crud ) , you will have to change out the pumps to the lower TBI units as these run at 65 PSi vs the 14 psi

for tank insulator we use a strip of heavy duty rubber truck mudflap . Pain to cut . but last for years . DO NOT use cloth as it traps the dust and salt dust on the roads and will cause corossion if it gets wet , if you want to go fancy go to a heavy truck dealer and they have tank insulator materials there . but a cheap $20 or roadside killed truck mudflap will make lots of insulators . ( farm and fleet has them )

fuel inlet should be 2" max ( nozzle is 3/4" O.D.) and you should have a vent on the farthest portion of the tank from the fill to the fill tube near the top so it will not trip the filling nozzle while filling it up . and the fill should be in the center of the tank not on the ends as the sloshing can pop the cap off unless you have a mechanical locking style cap that trucks use ( and you will then have to vent the tank ) , a in tank baffle is not necessary unless the tank is long , deep and narrow , and then it should be near the pump pick up point in the center ,
for a drain 1/2 NPT should suffice , try to make the bottom of the tank lower near this point . you do not want a flatbottom tank as it will oil can and drive you nuts with the sound , try to put ribs across the bottom or a crease to help this and if you this try to put the drain at the end and of the crease and pitch the tank towards the drain ( the crease should also act as a dirt and water trap . ( think of it as a inverted house shape )

as for attaching brackets to a tank your asking for trouble , either inside or out the tank should be smooth and snag free , any welds other than joints/seams should be avoided as it can start a tear if caught . and nothing should be hung on the outside

 

I just ordered on of these today. I'm doing the same thing you are. It's an Aeromotive Phantom Pump and runs just under $450. A lot of money but looks like a good solution.

http://aeromotiveinc.com/2012/11/phantom-fuel-system/

http://www.summitracing.com/parts/aei-18689/overview/

 

Since in tank pumps cost $190 each, plus I'd have to fabricated two installation rings, and two internal trays, (plus there is a depth issue) I am thinking that I might be better off with one in-line fuel pump.

Is there a brand that stands out as good quality and affordable?

Would I have an issue with having an air-lock or starving the pump when switching tanks?

 

go to rock auto for intank fuel pumps they are the cheapest and you can choose between brands for a tbi pump you can buy a Bosch turbine style ( better than a gearrotor , for 35 bucks each ,

as for EFI inlines never had one last , they always burn up as they cannot cool themselves good enough plus you do not want to run them dry .

and what is your definition of a tray ??? are you talking about a fuel bucket ? the part that goes around the pump to keep it full of fuel ?? or the baffle ?