More fuel system questions. Need opinions.

[Critter]

I'm just kicking ideas around. I currently have an early 80s style blazer tank in my 72 K5. Being from a carbureted blazer the tank has no baffles and uses barbed fittings on the top for fuel line connections. I like this tank because A) its 30+ gallons, B) it's in good shape, C) I already own it and don't want to waste money if I don't need to. I am working on transplanting in a 2006 LQ4 along with a frame up rebuild on the K5. So here is what I'm thinking.

Can I keep this tank along with its sending unit etc, put a high quality electric fuel pump on the frame and supply it with barb and clamp style fittings? I would then go from the fuel pump to the vettes style filter/regulator with high pressure line and of course from there forward use high pressure line to the 6.0 engine. Also, for the return off the filter/regulator I would use lower pressure hose and barb type connections back to the tank. My line of thinking is that the supply and return wouldn't be under the pressures of the main line going to the engine. Would this set up work??? Am I totally missing something??? What would be the downfalls of doing this? The baffle-less tank is something that everyone online seams to think is a no-no but I'm not sure why exactly.

If I need go out and buy a new baffled tank with sending unit and in-tank pump with all high pressure lines I have no problem doing that, I just wanted to make sure it was neccesarily. Please feel free to leave long winded detailed replies that look similar to this long winded question I just typed.

[lofly'a]

just a thought if you must get a new baffled tank is to use a 90-91 blazer tank. these 2models came with fuel injection and have baffled tanks in the 30 gallon size and will bolt up with no modifications. these were tbi units though but their is a in-tank pump that will work with the LS/LQ injection setups, but i can not find the application. i am still looking, and will post again when i find it.
the other option would be to modify your tank to accomodate a baffle/pump assembly but for the life of me i can not remember or find these sites.......YET.

[lofly'a]

found the link as an example to modify your tank:

http://www.tanksinc.com/index.cfm/pa...prod/prd84.htm

[Critter]

Originally Posted by lofly'a

just a thought if you must get a new baffled tank is to use a 90-91 blazer tank. these 2models came with fuel injection and have baffled tanks in the 30 gallon size and will bolt up with no modifications. these were tbi units though but their is a in-tank pump that will work with the LS/LQ injection setups, but i can not find the application. i am still looking, and will post again when i find it.

I planned get one of those tanks if I need to, its basically identical to what I have except baffeled (or so I've been told.) I was unaware of a factory style pump for that sending unit that would put out the psi I need for the LS fuel injection. IIRC the TBI in those years is around 40psi.

Originally Posted by lofly'a

found the link as an example to modify your tank:

http://www.tanksinc.com/index.cfm/pa...prod/prd84.htm

I like that, thanks for the link. My question remains though, WHY do I need a baffled tank for the LS fuel injection? What would happen if I used my existing non-baffled tank???

[OKGMC4]

If you never run it low on gas and never corner hard it would be OK but the reason you need baffles is to protect the in tank pump. In most cases the pump is in the tank to use the fuel to cool the pump. If it overheats it dies more quickly. Imagine a situation where you only have 1/4 tank gas and drive around a corner quickly. All the gas sloshes to one side of the tank and the pump is starved. I believe sucking air in the lines may cause the injection problems as well. The baffles provide a buffer zone for the pump. Mechanical pumps didn't have to worry about this as they were not high pressure and did not overheat.

[RocketKing]

The newer tanks also do not have baffles, the sending unit, filter, regulator and pump are contained inside an enclosed plastic "cup" inside the tank. Gas is held in this "cup", keeping everything wet. Therefore no need for the baffles.
I haven't decided about my pump yet, we are considering making the internal one out of the '04 'Burb work but I can help out on the filter/reg.
Follow this link for some good info

http://www.ls1tech.com/forums/conver...or-filter.html

Hope this helps.

[Critter]

Thanks guys, this is starting to make more sense now. Maybe I can get a complete 87-91 sending unit with the cup, swap out the pump to one (even if its universal) that will put out the 60 or so psi and put it all in my older style blazer tank. Surely the large port on top with the lock ring is the same???

[OKGMC4]

Originally Posted by Critter

Thanks guys, this is starting to make more sense now. Maybe I can get a complete 87-91 sending unit with the cup, swap out the pump to one (even if its universal) that will put out the 60 or so psi and put it all in my older style blazer tank. Surely the large port on top with the lock ring is the same???

It's been years since I worked at the parts store but I think TPI camaro pumps are really close to tbi pumps. Same outer dimensions. May interchange in the sender but can't remember if the plug is the same. TPI also requires high pressure.

[gringoloco]

Most of the GM style pumps are identical externally and mount the same way. Even the same as some of the F*rd stuff. Should be able to put one directly in place where the TBI pump would mount. YMMV.

The 87-91 Blazer tank setup has the 'cup' integrated into the tank, unlike the later model setups, which have it integrated into the sender. The 'safe' way to do it is with the new tank, and yes, the mounting ring is the same, so if you wanted to use the 87-91 sender in your tank, you could.

Frame mounted pumps are noisy, I think you'd probably end up switching to the in-tank if you went that route.

[usmcchevy]

Originally Posted by Critter

Thanks guys, this is starting to make more sense now. Maybe I can get a complete 87-91 sending unit with the cup, swap out the pump to one (even if its universal) that will put out the 60 or so psi and put it all in my older style blazer tank. Surely the large port on top with the lock ring is the same???

I have the stock pump from my motor if you want to try it on your sending unit, yours for the cost of shipping.

[DirtyLarry]

Critter,

Grab an ’87-’91 tank and sending unit then replace the TBI fuel pump with an AC Delco EP241 fuel pump. This pump will be a direct fit to the TBI sending unit but delivers much higher pressure. The EP241 is the Corvette and F-body TPI pump. This is the pump I am using to run my 8.1L by way of an ’87 C/K fuel tank and sending unit. Unregulated, the EP241 is good for over 100 psi.

The EP241 fuel pump is only $79 though Summit Racing and is a genuine GM part. I bought 2 and keep a spare in the camper just in case it craps out while we are in the middle of nowhere on one of our excursions.

EP241

[DirtyLarry]

Here is a better picture of the EP241 components. For $80 it is a heck of a deal!

[Critter]

Originally Posted by DirtyLarry

Critter,

Grab an ’87-’91 tank and sending unit then replace the TBI fuel pump with an AC Delco EP241 fuel pump. This pump will be a direct fit to the TBI sending unit but delivers much higher pressure. The EP241 is the Corvette and F-body TPI pump. This is the pump I am using to run my 8.1L by way of an ’87 C/K fuel tank and sending unit. Unregulated, the EP241 is good for over 100 psi.

Originally Posted by DirtyLarry

Here is a better picture of the EP241 components. For $80 it is a heck of a deal!

I KNEW there had to be a high pressure pump out there that would go right in place of the TBI pump. I think this is the route I will go, sounds like a good plan. I only wish I could use the tank I have, but it's not the end of the world to buy an 87-91 style. Thanks!