thinking ahead about fuel supply

[jiggityjoe87]

hey everybody I'm in the middle of piecing together a fuel system for my 70' suburban 2wd 1/2 ton and I've been reading everybody's posts about getting an 87-91 tbi blazer/suburban fuel tank and adding a tpi pump. Well I'm going to try and make it work in my suburban so I went to the junkyard today. lo and behold they had a 90 suburban 3/4 ton 4x4. so I started taking the tank down after about 45 minutes i had the tank on the ground only to realize that the junkyard punched holes in the tank . After all the struggle I figured I couldn't come home empty handed so I took the sending unit/internal pump and now I'm in search of the specific capacity fuel tank it came from. I took the dimensions of the tank before i left. The tank is 35in long X 28 in wide X 12 in tall. Lastly when it comes to the TPI fuel pump I've read a lot of people saying get an 85' fuel pump, but then I think to myself the only tpi engine that year was a 305. Are all TPI pumps the same? because 87' was the first year of the 350 TPI. I just don't want to go through all this work just to put in a pump that can't support the engine.

[jkade]

you can put a vortec pump in the sending unit if you wish. I have a 96 vortec pump on a 91 sending unit running a cammed LQ9.... runs great.

Tank from advance auto 31 gallon.... they matched rock auto's price.... i think it was around $90

[jiggityjoe87]

[QUOTE=jkade;4419488]you can put a vortec pump in the sending unit if you wish. I have a 96 vortec pump on a 91 sending unit running a cammed LQ9.... runs great.



now when you say you put in a 96' vortec pump is that the one that was meant for the suburban/trucks? For some reason I thought that they were also TBI. But if your running an LQ9 then it must be providing enough pressure.

I know this forum is for LSX swaps but I'm actually installing an LT1/4L60E from a 95' camaro. Does anybody know what kind of fuel pressure this motor requires versus say a TPI motor or an LSX motor. I also know that the fuel system is supposed to have a return line and there is a fuel pressure regulator on the fuel rail. What I'm scratching my head about is can I send as much fuel to the regulator as I want and will it automatically regulate it down to the factory settting? I just don't want to put on a pump and then all of a sudden have way more psi at the injectors then what was intended from the factory.

[jkade]

[quote=jiggityjoe87;4420687]

Originally Posted by jkade

you can put a vortec pump in the sending unit if you wish. I have a 96 vortec pump on a 91 sending unit running a cammed LQ9.... runs great.



now when you say you put in a 96' vortec pump is that the one that was meant for the suburban/trucks? For some reason I thought that they were also TBI. But if your running an LQ9 then it must be providing enough pressure.

I know this forum is for LSX swaps but I'm actually installing an LT1/4L60E from a 95' camaro. Does anybody know what kind of fuel pressure this motor requires versus say a TPI motor or an LSX motor. I also know that the fuel system is supposed to have a return line and there is a fuel pressure regulator on the fuel rail. What I'm scratching my head about is can I send as much fuel to the regulator as I want and will it automatically regulate it down to the factory settting? I just don't want to put on a pump and then all of a sudden have way more psi at the injectors then what was intended from the factory.

The vortecs used as much pressure as the ls motors, they had what was called a spyder pack injector system (a bank of injectors under the intake with a line going to each cylinder). You LT1 calls for 45psi so I am not sure if the vortec pump will be too much for the LT1 regulator but I am almost certain that a LT1 corvette pump will fit just the same.

[jiggityjoe87]

after doing some more searching I found out that I took the sending unit from a 40 gallon tank. Then I started thinking that I only really want a maximum capacity of the 31 gallon tank. So now I have the sending unit/pump for the 40 gallon tank but can I use it on the 31 gallon tank and still have the sending unit function properly?

[jkade]

Originally Posted by jiggityjoe87

after doing some more searching I found out that I took the sending unit from a 40 gallon tank. Then I started thinking that I only really want a maximum capacity of the 31 gallon tank. So now I have the sending unit/pump for the 40 gallon tank but can I use it on the 31 gallon tank and still have the sending unit function properly?

I bet it will be too long, I think the 40 gallon tank is deeper but I am not sure. I think my sending unit from rock auto was about $120 shipped... dang expensive if you ask me but that was the cheapest place I could find one.

[jkade]

Maybe this will help.

DORMAN Part # 576313 {#15615624} Dimensions: 28-3/4" x 28-1/8" x 12-3/4" / Gallons: 31 / Liters: 118 / Lock Ring # LO01
31 Gallon (Only 4 Remaining)

DORMAN Part # 576349 {#15615625} Dimensions: 35" x 28-3/4" x 13-1/8" / Gallons: 40 / Liters: 151 / Lock Ring # LO01
40 Gallon

[jiggityjoe87]

hypothetical situation. Say I buy a 31 gallon gas tank and use the 40 gallon sending unit I already have. and during the progress of the build i hook up the electrical connections to the sending unit with the gas gauge to see where it registers on the gas gauge. In the long run is there a way of augmenting the position of the gas gauge needle to be where it needs to be in relation to the actual gas level in the tank

[jkade]

Originally Posted by jiggityjoe87

hypothetical situation. Say I buy a 31 gallon gas tank and use the 40 gallon sending unit I already have. and during the progress of the build i hook up the electrical connections to the sending unit with the gas gauge to see where it registers on the gas gauge. In the long run is there a way of augmenting the position of the gas gauge needle to be where it needs to be in relation to the actual gas level in the tank

You could bend the float tube rod to make it read correct. All you would have to do is use a ohm meter, put say 5 gal of gas in it and get the float to read 0ohm and you would have a 5 gal reserve.

[jiggityjoe87]

that sounds like a good idea i might just have to do that.

[jiggityjoe87]

I still have the 95' camaro gas tank with in tank pump I may just take that out and see if I can adapt it to the suburban tank

[jkade]

Originally Posted by jiggityjoe87

I still have the 95' camaro gas tank with in tank pump I may just take that out and see if I can adapt it to the suburban tank

Never hurts to try, it might work.