Explain to me why i can't run a 73' gas tank on my EFI L28ET swap... pretty please?

[Guest 73Turbo240z]

If i were to keep the tank above half full, and not race on anything less than 3/4 of a tank, is there any reason why i couldn't cobble my Z along for the time being running my turbo L28ET motor off the 73' 240z gas tank?

 

I'd put a walboro 255lph pump inline obviously, and probally inline filter also, that would allow me to retain my stock gas gauge and sender, and most of all, allow me not to have to try to fab a tank last minute.

 

I originally had sorced a 280z gas tank, however, upon looking at it compared to a 240z gas tank, it became glaringly obvious that the 2 weren't as "direct swap" as the searches would tell you.

 

The 240z gas tank has a very large notch in the side of it that allows the spare tire well to protrude down next to the tank. Where as the 280z tank is one giant rectangle (more twinkie shaped actually) and they raised the spare tire well and created a false floor. So in order to make the 280z EFI tank work, i'd either have to:

 

A: lose my tire well still, which is what i've been trying to avoid all along.

 

B: Cut and re-skin an area of the 280z tank to follow the lines of the 240z tank, which at that point i'm already modifiying a tank, so why am i not just cutting up the 240's?

 

C: go fuel cell, which i really don't want to do for a combination of A: and the fact that i really dislike the idea of any part of the fuel system sans the filler neck protruding into the cabin of the car, i realize some of ya'll have built self contained boxes that seal the cell in it's own area, but factor back to reason A. Then theres the fact my girlfriend will be in this car from time to time, and it's one thing for me to drive a car i built, knowing the risks of a fuel system that has it's storage in the cabin, but i don't feel thats a risk i'd want her taking.

 

So if anyone has suggestions on how to field this, or spotted somthing i missed, i'm all ears.

[Guest bastaad525]

I've been running my L28ET swap with the stock '72 240 fuel tank for two years and not once had a problem. And I drive the snot out of my car, in a straight line, and up a certain twisty local mountain road as well, and never so much as a hiccup.

 

I will usually get the fuel gauge let down around E before refilling... 240z fuel gauges are notorious for not being very accurate, and most people agree there will be at least a few gallons of fuel left in the tank by the time the gauge reads E. But of course, no one really knows for sure

 

I'm using the stock 240 fuel feed line, and a larger return line. I'm using the drain in the bottom center of the fuel tank as the feed.

 

If you're racing on a track, I'd think you'd be fine as long as you keep it over 1/4 tank? maybe 1/2 I dunno.

 

And I think some 280z tanks ARE direct swap and then they made a change at some point so I think later 280z tanks will NOT work but earlier ones will.

 

Anyways, I guarantee you will be FINE running the 240 tank on the street at least, never been on track myself so couldn't say for sure, but in a straight line you'd be fine just keep it over 1/4 tank.

[Sparky]

the only tank that will bolt into the 240Z is from the Fuel injected 260Z...1975 to be exact....and good luck finding one in decent shape.

 

You have several options, all of which are perfeclty viable:

 

1. run the stock 240Z tank using the drain as your new pickup, run new 3/8s alum fuel line (cheap) and use the stock feed line as your new return.

 

2. run the stock 240Z tank using the drain as your new feed, run a LP pump feeding a surge tank and then your walbro to feed from the surge tank using 3/8 alum line, running the stock feed as the new return into the surge tank (as is typically done)

 

3. tank your 240Z tank off and have it hot tanked, contact summit, Jegs, or Brad from this board and buy a sump. properly install it and run your feeds from it using one of the two options above.

 

I started my turbo project with the sump and never had any fuel problems (in the short time I drove it) now that shes getting rebuilt again I will use option 3 and option 2...only I will be running two LP pumps feeding into the surge tank then onto a paxton Kamikazi 750HP pump 3/8 (-6) feed.

 

easy as pie.

[Guest 73Turbo240z]

the only tank that will bolt into the 240Z is from the Fuel injected 260Z...1975 to be exact....and good luck finding one in decent shape.

 

You have several options' date=' all of which are perfeclty viable:

 

1. run the stock 240Z tank using the drain as your new pickup, run new 3/8s alum fuel line (cheap) and use the stock feed line as your new return.

 

2. run the stock 240Z tank using the drain as your new feed, run a LP pump feeding a surge tank and then your walbro to feed from the surge tank using 3/8 alum line, running the stock feed as the new return into the surge tank (as is typically done)

 

3. tank your 240Z tank off and have it hot tanked, contact summit, Jegs, or Brad from this board and buy a sump. properly install it and run your feeds from it using one of the two options above.

 

I started my turbo project with the sump and never had any fuel problems (in the short time I drove it) now that shes getting rebuilt again I will use option 3 and option 2...only I will be running two LP pumps feeding into the surge tank then onto a paxton Kamikazi 750HP pump 3/8 (-6) feed.

 

easy as pie.[/quote']

 

I think i'll vote for option 1 till i can find this rare 260z tank or i cave in and go fuel cell. Surge tanks sound good on paper, but i'm still weary of the idea of essentially a beer can full of gas sitting on the car somewhere... then again the stock gas tank isn't far off from that i suppose.

 

Does anyone know if the same foam they use in cells could be used in a stock gas tank? i didn't know if the factory fuel gauge setup would get in the way.

[proxlamus©]

buy a fuel cell..

 

my buddy Mike is using a fuel cell in the stock spare tire well.. without modifications.. and has 2 metal brackets hoolding it on.

[drzed]

First things first - there are no fuel injected 260Zs in North Americia - only 280Zs were injected.

 

The tanks in 280Zs come in two very distinct shapes. 1975 and 1976 tanks are similar in shape to 240 and 260Z tanks and should be an easy swap (although I have never swapped one myself). 1977 and 1978 tanks are the "twinke" shaped tanks and would not fit without major modifications due to the loss of the full size spare tire well in the floor on the later cars.

 

I don't know about the use of the stock tank for the twisties but for straight line you will be OK if you maintain at least 1/4 - 3/8 of a tank depending on the HP of your car and the amount of traction you have. I was fine running 1/4 of a tank in my 260Z (with a Walboro pump) until I bolted on a set of slicks - then I had to maintain at least 3/8 of a tank to avoid the horrible surge of launching and then running out of gas at the 60 ft mark.

[Guest 73Turbo240z]

First things first - there are no fuel injected 260Zs in North Americia - only 280Zs were injected.

 

The tanks in 280Zs come in two very distinct shapes. 1975 and 1976 tanks are similar in shape to 240 and 260Z tanks and should be an easy swap (although I have never swapped one myself). 1977 and 1978 tanks are the "twinke" shaped tanks and would not fit without major modifications due to the loss of the full size spare tire well in the floor on the later cars.

 

I don't know about the use of the stock tank for the twisties but for straight line you will be OK if you maintain at least 1/4 - 3/8 of a tank depending on the HP of your car and the amount of traction you have. I was fine running 1/4 of a tank in my 260Z (with a Walboro pump) until I bolted on a set of slicks - then I had to maintain at least 3/8 of a tank to avoid the horrible surge of launching and then running out of gas at the 60 ft mark.

 

realistically i'll be putting down 350+hp and 400ft lbs of torque easy.

 

And yea, i have the 77-78 twinkie gas tank as my spare unfortunately...

[Guest 73Turbo240z]

I also thought i'd mention, we just got done fine tuning another board members Z here this evening... junk yard motor w/ 90k ish on it, stock t3, crush bent 2.5" piping, volvo fmic, stock ems + afpr + 255lph...

 

his is fast... very fast... its the 1st turbo Z i've ridden in... it honestly kinda frightens me if his is that good with a relatively low tech build, given the amount of higher end overbuilding i've done to take much more boost and support a larger turbo... i'm kinda scared of what i might be creating.

 

it's fun.

[Sparky]

First things first - there are no fuel injected 260Zs in North Americia - only 280Zs were injected.

 

The tanks in 280Zs come in two very distinct shapes. 1975 and 1976 tanks are similar in shape to 240 and 260Z tanks and should be an easy swap (although I have never swapped one myself). 1977 and 1978 tanks are the "twinke" shaped tanks and would not fit without major modifications due to the loss of the full size spare tire well in the floor on the later cars.

 

I don't know about the use of the stock tank for the twisties but for straight line you will be OK if you maintain at least 1/4 - 3/8 of a tank depending on the HP of your car and the amount of traction you have. I was fine running 1/4 of a tank in my 260Z (with a Walboro pump) until I bolted on a set of slicks - then I had to maintain at least 3/8 of a tank to avoid the horrible surge of launching and then running out of gas at the 60 ft mark.

 

Thanks for the clarification, I don't know what made me think that '75 model year was a 260Z, at one point in time I had a 75 280Z...Sorry for the brain fart...at least I got the year right. Although I was under the impression that only the 75 tank would work and not the 76-78, again, thanks for the correction!

 

...back to work.

[Guest bastaad525]

I also thought i'd mention' date=' we just got done fine tuning another board members Z here this evening... junk yard motor w/ 90k ish on it, stock t3, crush bent 2.5" piping, volvo fmic, stock ems + afpr + 255lph...

 

his is fast... very fast... [/quote']

 

heh, that's about exactly what I have in my Z, just a better I/C

 

So does that mean my car qualifies as fast.... very fast? Sweet

 

Well as I said... I've been using the stock tank just fine for quite some time with the stock feed, dynoed at 14psi and had plenty of fuel (also using an RRFPR).

 

And I guess others have confirmed what I said above, that the first couple years of 280z fuel tanks will bolt in to the 240. I also like the idea of putting a sump on the stock 240 tank, probably cheaper to do than buying a replacement, and you gotta R and R it either way. I've been thinking of doing this myself for quite some time.

[drzed]

Ya I like the idea of sumping the early tank as well. I was thinking of getting it boiled out and welding a sump under the existing drain about the size of a small cake pan - approx. 1 litre in size (I might even use one of my wifes cake pans but don't say anything). Then I would plumb a 3/8" line in and out and weld another drain plug in the bottom of the pan. Should work perfect and allow me to run about 5 gals less fuel at the track.

[Guest bastaad525]

my only wish is that someone had suggested this to me BEFORE I had my tank dropped and cleaned/recoated.

[racerx260]

I Have Stock 83 Turbo In An Early 260.running 10 Psi Right Now And Run Tank To Almost Empty And Have Had No Issues.i Had To Put A Stepdown Between The Turbo Fuel Pump Inlet And The Smaller Tank Outlet Without Any Problems. I Am Also Useing The Stock Return Line On The Tank And Have Not Encountered And Rich Issues That Many Have Said Would Occur At Idle Because Of Too Small A Retun Opening On Stock Tank. The Outgoing And Return Line Connections On The Stock 260 Tank Are Both The Same Size.i Live In The Mountains And We Sure Have Our Share Of Twisties.you Can't Run Flatout For Very Long Up Here And May Be Why I Haven't Experienced And Fuel Starvation Issues.

[akeizm]

I dont know if its the same over in the states, but my 260z had a stock return line but it was blocked off at the carbie fuel rail. And both the tank inlet and outlet are next to each other. Now do all earlier model Z's have a fuel return line run? (The Z I have has never had an efi motor until now). I've had mine down pretty low haven't noticed any surging with the stock tank.

[Roostmonkey]

Yes they all came with a return line. I installed my sump inside the tank. I cut a 4"x4" hole around the drain, rolled up a 3" diameter cylinder x 3-4" tall with 2, 1/2" tubes running into the bottom/side of the cylinder to allow fuel into the sump but restrict its flow back out and welded it to the inside of the pc I cut out.The cylinder was positioned so that the pick-up and return were down inside it when I re-welded the 4"x4" pc back into the tank.

[evildky]

I had tons of fuel delivery problems from my stock 71 tank even when running carbs, mine turned out that the origional pickup had colgged years ago and some prior ownder had added a new pickup tube which was a copper tube cut at an angle and brazed into the side of the tank and pointing kinda towards the bottom middle of the tank, and inside the stock tank was a simple short "wall" running front to back right over the crain plug about 2 inches takk and this was the only baffeling in the tank, the stock pickup tube went to roughly the same place

 

I sumped my tank just to be certain I got the fuel I needed, I then ran from the sump a 1/2 aliminum line to the front of the tank with an inline fuel filter to a msd pump and then I ran 3/8 aluminum fuel line all the way up to my palnet o-ring fuel rail and into the aeromotor rising rate fuel pressure regulator and all the way back to the tank to a bulkhead I installed on the front of the tank, no more fuel problems

[dat240zg]

There is a guy that builds sumps specifically for the 240 tank.

 

I had his email for a while and then lost it. I'll try to find it for everyone. If memory serves me, the cost was $65 and it was a perfect fit.

 

Bryan

Dat240zg

[cygnusx1]

At Watkins Glen during the 2005 ZCCA I went out for my last stint of the day with 1/4 showing on the gauge. Going up the last hill into the blind left-hander, the Z was starving dry. I pulled into the pits where my instructor had a five gallon can of gas. I dumped in about half of his fuel and went back out with no more issue...other than I owed my instructor gas money

 

I run stock fuel tank and lines in my 76Z Turbo with stock pick up points. Maybe I should switch to using the drain plug too....hmmm.

[Guest 240Zdragon72]

Would anyone have pictures of the drain plug option and how it looks when it is done? This could save me money in the long run without having to get a fuel cell and upgrade all the lines right now.

[Guest bastaad525]

With the stock '72 tank and using the drain at the bottom as my feed, I do notice if I run my tank really low, like 1/8 or less showing on the gauge, then I do have to be careful. When I make turns or go up slight inclines (like driveways) I will hear the fuel pump note change (buzzzzzzzzzzzzzBUZZZbuzzzzz) and I have a VERY strong feeling that that is the sound of it sucking up air. So I do make it a habit to either keep it above 1/4 or not to drive it hard if it's lower than that just in case.

 

The big problem I think, with the 240, is that the stock fuel gauge sucks and is really not a good indicator of how much fuel you actually HAVE.