fuel injected gas tank baffle

[blazinzuk]

Has anyone taken apart a fuel injected gas tank?

I want a good picture of the baffle surrounding the pump.

Fuel cell is going to be built sooner than later.

I just need to know how to baffle everything so it runs like stock

 

[4X4HIGH]

The tanks don't come apart but basically all it is is a plastic tray if you will that is attached to the bottom of the tank where the fuel pick-up sits in. The tray is about 2" tall to keep fuel at the pick-up.

 

[blazinzuk]

The tanks don't come apart but basically all it is is a plastic tray if you will that is attached to the bottom of the tank where the fuel pick-up sits in. The tray is about 2" tall to keep fuel at the pick-up.

Any holes in the bottom or just a tray 2" tall?

oh and tanks come apart, just can't be easily put back together .

I don't want to tear down my good 31 gallon tank just to see

 

[4X4HIGH]

Any holes in the bottom or just a tray 2" tall?

oh and tanks come apart, just can't be easily put back together .

I don't want to tear down my good 31 gallon tank just to see

Yep, just a 2" or so tall baffle tray without any holes. The fuel return line dumps into the baffle tray to help keep fuel at the pick-up tube even when the tank is near empty. Are you going to be running TBI or some other MPFI? I have discovered that if you're running a higher than stock pressure pump the baffle really doesn't even matter anymore. When I was running the factory pump when I was at 1/4 tank and made a hard turn the truck would want to stall for a second because the fuel would slosh away quickly but ever since I installed a high pressure pump this is no longer an issue even when I have only 1 gallon of fuel left.

 

[blazinzuk]

Not for a long while.

The next motor to go in Horton will be a 5.3 or a 6.0. So I need to consider that.

Realistically I will be running the stock TBI for a while. Even if I go wheeling twice a month that's not many miles or hours on the motor.

 

[sixb]

Not for a long while.

The next motor to go in Horton will be a 5.3 or a 6.0. So I need to consider that.

Realistically I will be running the stock TBI for a while. Even if I go wheeling twice a month that's not many miles or hours on the motor.

I thought you were gonna run Russel's old 6.5 4l80e setup and a new fancy 241/205 doubler?

 

[blazinzuk]

I thought you were gonna run Russel's old 6.5 4l80e setup and a new fancy 241/205 doubler?

Russels 6.5 pretty much blew up before the deal could be made. So I stick with the ol reliable 350

 

[yellowK20]

I have a FI blazer tank here at the house I could cut it apart I guess

 

[4X4HIGH]

There's no need to cut apart a tank. The factory baffle tray is plastic and most of them are broken to pieces.

 

[eagle mark]

If your building a fuel cell then why not use a newer fuel pump assembly? Return drops in the bucket around pump, no need for baffles...

 

[Stomis]

If your building a fuel cell then why not use a newer fuel pump assembly? Return drops in the bucket around pump, no need for baffles...

Even the replacement metal tanks for our trucks dont have baffles. My repop blazer tank has a "bucket" the size of a small square with rounded edges dinner plate that sits about 2-3in tall and the fuel pickup sock and return dump into that.

You could easily make a non FI tank into one with some sheet metal and a break. Im doing it to two 31 ford sedan saddle tanks right now at work cause the guy doesnt want a duece drum hanging out the back and thats the only fuel injection tank they make for the car.

 

[dyeager535]

The stock plastic baffle as I recall was indeed a small plastic "box" that was open on top, but the fuel passages were something like a maze....the fuel had to travel through a passage around three of the four corners of the sump before it got to where the pickup was. That way, if the truck was off camber in any one direction, the fuel couldn't flow back out. IMO a far superior solution to the aftermarket, if it weren't for GM using plastic instead of steel.

My Spectra tank has the ineffective "bucket" in the bottom, and while I've not ever stalled the engine from starving the pump, I don't do a lot of steep angles, and normally don't let it get below 1/4 tank off-road.

 

[4X4HIGH]

The stock plastic baffle as I recall was indeed a small plastic "box" that was open on top, but the fuel passages were something like a maze....the fuel had to travel through a passage around three of the four corners of the sump before it got to where the pickup was. That way, if the truck was off camber in any one direction, the fuel couldn't flow back out. IMO a far superior solution to the aftermarket, if it weren't for GM using plastic instead of steel.

My Spectra tank has the ineffective "bucket" in the bottom, and while I've not ever stalled the engine from starving the pump, I don't do a lot of steep angles, and normally don't let it get below 1/4 tank off-road.

I've replaced a pump in my FACTORY tank and the tray was just a plain simple squarish open tray, no "mazes" whatsoever.

 

[dyeager535]

I replaced a K5 one I had back in the day, it had the "maze". Not really a maze, just a box around a box, with one side (and the top) open.

No idea if they made different tank/baffle designs or what. It (had) been held to the floor of the tank with the metal pins and the spring steel clips, which had pulled through the baffle.

Here are detailed photos of the setup, if from '87 saddle tanks. Pictures not mine: http://67-72chevytrucks.com/vboard/showpost.php?p=4992939&postcount=10http://foamypirate.com/img/87chevy/misc/fuel_baffles/image001.jpg

 

[blazinzuk]

I am going to put baffles in the tank no matter what I was just wondering what the below the pump was like. I am basing it off a road race type of setup.

 

[dyeager535]

Just below the pump the tank is just flat. Tank design didn't change, the pickup location AFAIK didn't change, GM simply added the baffle around that location.

I agree with EagleMark, if they are/were available, the integral pump/baffle setups would probably be pretty slick to run. At least some of those type are also "one piece" (or so I was told) and the pumps aren't replaceable by themselves, leading to increased cost.

But of all I have seen, the stock baffle setup, recreated in steel, would be my choice if I was actually building a tank and could do the work to install the baffles. I *still* don't trust the pan in the bottom of the tank I have now...for a car that just saw hard launches or cornering, it might work (within reason) but for trucks that see all sorts of angles for prolonged periods of time, under throttle, they are a poor design. I mean really...the pan even has holes in the bottom of it...lets fuel in, and lets it out too.

 

[blazinzuk]

I am going to duplicate the stock Chevy baffle for the pump itself. It has served me very well. I am also going to add baffles in the tank itself. Not a ton but it should help somewhat keeping the fuel controlled.

Really probably don't need them but I am going to build a rack and mount it on top of the gas tank. So the baffles are going to be there to stiffen the gas tank up a bunch too. Baffles will be right in line with where the rack will sit

 

[dyeager535]

Sounds like you have it worked out pretty well. Obviously fuel slosh is a concern, or it wouldn't break the stock baffling so regularly!

Depending on depth of the tank, I wonder if extending the "sump baffle" higher would help keep fuel dumping into it on angles? Or simply putting a tube on the return that fits down further? With TBI fuel pressure is already pretty low, I assume the return pressure isn't much, so on angle maybe it actually misses the sump? I've never really considered the return function...might as well over-engineer it! lol

Depending on the size of the tank you are building, maybe you could just run baffles from each corner of the sump to separate the tank into three sections? Or radiating out from each corner of the sump to the corners of the tank, to divide it into four sections?

 

[blazinzuk]

Depending on the size of the tank you are building, maybe you could just run baffles from each corner of the sump to separate the tank into three sections? Or radiating out from each corner of the sump to the corners of the tank, to divide it into four sections?

I like that idea. Might have to do that. I haven't truly taken the measurements for the tank yet. I need to get the rear bedsides off ( super easy) and I will probably start building it before I start on the new cage. Pretty much going to redo my rear seat mount gas tank and storage in the rear of the truck

 

[Blue85]

Yep, just a 2" or so tall baffle tray without any holes. The fuel return line dumps into the baffle tray to help keep fuel at the pick-up tube even when the tank is near empty.

If there are no holes, how does the gas get into the tray?

I have the little steel dish thing in the bottom with one small hole on each side (aftermarket 31 gal TBI tank). It does starve for fuel when the tank gets low. I don't know what affect the higher pressure pump (TPI) has versus the TBI ones. It is fairly well documented in other threads that the plastic baffles work better, but break.

The newer setups with tank inside the tank work really well and you can usually drain the tank completely. My car has a check valve on the bottom of the plastic tank and the return line feeding into the plastic tank. I've taken the pump out before where that inner tank was over 1/2 full while the surrounding tank was almost empty. My only complaints are that it gives no warning and if it is run dry needs like 3-4 gallons before it will run again. I don't see why one of those plastic inner-units couldn't be retrofitted into some other tank/cell instead of fabbing some baffles. You just need the large style top opening.