Fuel tank/fuel pump question...

[406shark]

Hello,

I am going to redo my current fuel set-up for next season. My question is this...

I have a stock fuel tank in my '77 that is currently feeding a Carter electric fuel pump. It is hooked to the factory 3/8ths line. What I would like to do is add another fuel pump (hi volume/hi pressure type) that I can feed into a seperate fuel line for when I race. My thought was to run the two lines to a regulator, then into my Mighty Demon carb.

Does anyone know if it would work to add a fuel pickup point to the bottom of the factory tank to feed the added fuel supply? I realize that I will need to remove the bladder that is currently inside the tank. The bladder is starting to shrink up...it now only holds 14.1 gallons instead of the stated 17.0 gallon capacity.

The current Carter pump was working on the street, but at the track this season I was running it out of fuel at the top of 2nd gear. I have an extra new Carter (backup unit) that I thought I would install for normal driving, but install the new (hi volume/hi pressure unit) to only activate when racing. Any thoughts?

Any help would be appreciated.
Thanks, Jeff

 

[AKRAY4PLAY]

i am running a 600 hp 406 in my '77. i also use the stock fuel line into a high pressure high capacity mechanical pump. that runs into a by-pass type pressure regulator that dumps extra presure to the factory bypass/return line to the tank. by circulating the fuel, it keeps it cool so i dn't have problems with fuel boil in the carb or vapor lock. i am not running nitrous, and doubt i have enough extra flow from the stock line to supply fuel for a nitrous system.

have you looked at your pick-up filter inside the tank?? they tend to clog up and implode over the years. several people have had problems with then feeding high hp motor in the recent past.

have you considdered a fuel cell?? it would give you more fuel capacity, larger outlet line, leagal for racing, easy to mount and plumb, etc. it is the path i'm going when i get bored with my car and need the nitrous for the extra kick of fun.

 

[bossvette]

I have an early non bladder tank in my 76 with a in tank pump conversion for the TPI setup. It fits but the filler cap is a little off but is out of sight.

 

[Vettehead Mikey]

You'd probably do more harm than good by putting more pumps with more pressure and flow.

The stock set up is more than enough to supply any small block, your problem might be elsewhere

 

[406shark]

Thanks for the input. Here is a rundown on my situation.

Last season my best et was a 11.88 @ 116.12 mph. Since then I freshened the engine with a valve job, new springs, rings and bearings. I also removed just over 100 lbs of dead weight.

This season the one chance I had to take it to the track I got a best of 12.599 @ 106.47 mph. The car was laying over as it shifted into high gear. It quit pulling.

I checked my Mighty Demon and found that the secondary was empty and the primary was very low. When I got the car home I unhooked the fuel line from the carb and tested my fuel flow. I was getting only 1/2 gallon in 40 seconds! I then tested before the fuel filter, no difference in flow. BG states that I should be pumping 1 gallon in 20-25 seconds.

The pump is a Carter rated at 7 psi. My idea is to use the new Carter I have laying in the garage for day to day driving. In nice weather I drive it to work a few times a week (about 20 miles each way). Then run a seperate pump and line to a regulator just to use for racing. I would set the regulator at appx. 7 psi. I thought with the seperate fuel system I would add more volume at the same pressures. I like the idea of having the option of a backup pump for reliability. My friend next door wires up police and trooper cars for a living. He will be hooking them up to relays and installing the electrical part of the system.

I would love to run a fuel cell, but I haven't found one that will fit in the factory location.

I too have been thinking of adding a NOS kit for an added kick in the seat. I figure my dual fuel system should work great if I do decide to run it.

Thanks,
Jeff

 

[AKRAY4PLAY]

Jeff,
sounds like your in-tank filter might be plugged or collapsed. another problem is your current fuel pump might be worn out. i've seen electric pumps chew up plastic impellers and loose the ability to pull fuel. mechanical is better for pulling, and electric is better for pushing fuel. the BG electric pumps are tough and when ran with a by-pass style pressure regulator work very well. dead heading fuel pressure will lead to early failure. i like to plumb in a return line for a couple reasons. constant flow reduces fuel temp resulting in better performance. also vapor lock is vertually eliminated. the biggest reason is your fuel pressure to the carb remains more constant. a nice even pressure is easier to tune as well. with a flowing, or dynamic, system, you do not need to get the fuel moving from a stop so supply is more constant. hope i haven't confused you, it's way late in day i haven't slept in 36 hours. i can send you some ideas i have about fuel cells when i get it figured out, if you're interested. later, Brian.

 

[406shark]

Jeff,
sounds like your in-tank filter might be plugged or collapsed. another problem is your current fuel pump might be worn out. i've seen electric pumps chew up plastic impellers and loose the ability to pull fuel.

I believe that is what happened to my old pump. I pulled the pump off today and plan on pulling the pickup assembly out in the next couple of days to check it out.

i can send you some ideas i have about fuel cells when i get it figured out, if you're interested. later, Brian.

I would appreciate any input concearning fuel cells that will fit in the stock location on our year Vette. Feel free to e-mail direct if you wish.

Thanks again,
Jeff

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