Fuel tank relocation to rear? Options

[Mendivil26]

Story time:
Last time I parked my '75 2.0 to restore the front suspension, it was running relatively fine.
As usual, a simple task estimated to take a few weeks turned into months, due to lack of time & budget. A few months go by and I notice the interior is flooded in gas, thankfully the car had no carpets and nothing caught fire.

I did my research and diagnosed the leak came from the plastic fuel lines that go through the tunnel; simple enough, I'll replace them with SS lines.
I go ahead and clear the interior of any remaining fuel; drain the rest of the gas tank, only to notice the horrible condition it's in; chunks of rust coming out of it.
Now I not only have to replace the fuel lines but I also have to either restore the tank or replace it (dansk tank $230 plus SS line $170).

My goal with this car is to turn it into a baja inspired 914; and since I don't really care about "originality", I wondered: what if I replaced it with a universal fuel tank used by dune buggies/prerunners (Jaz, RCI, etc) and placed it in the rear trunk?
They seem to be easy to find secondhand and not so expensive.

I started looking into it and noticed obviously 914 racecars have "fuel cells" but they all kept them in the front.

This is a list of pros & cons I came up with, and since it hasn't been done before I assume that it'll be a very unpopular inion, so please go ahead and talk me out of it since I'm biased and can only think of reasons to actually do it.

Pros:
No fuel lines running through tunnel = simpler system & shorter lines.
Less or just as expensive for a unique or "custom" look, since I've never seen it done before.
Shifts weight to the rear, which is better for my application

Cons:
Safety? Rear suspension is being reinforced so the tank could be protected by the cage I'll build around it in case of a rear end accident, but the fact that it's closer to the engine and hot temperatures might be a bigger issue.

Anything else I might not be considering?
Has someone seen it done before?
If so, please share pictures/info.

Picture of how it sits right now with UTV tires, for reference:


Picture of what I'm thinking of maybe doing:

[ClayPerrine]

That is an absolutely terrible idea. The rear trunk is a crumple zone, and you would be putting the gas tank in harms way. Believe me, I know.

And putting the gas tank above the hot engine/transmission is a really bad idea too.


Leave it where it was put originally. If the tank is bad, there are new ones available, or people on here have good used ones to sell.

[ValcoOscar]

That is an absolutely terrible idea. The rear trunk is a crumple zone, and you would be putting the gas tank in harms way. Believe me, I know.

And putting the gas tank above the hot engine/transmission is a really bad idea too.


Leave it where it was put originally. If the tank is bad, there are new ones available, or people on here have good used ones to sell.

(IMG:style_emoticons/default/agree.gif) w/ Clay

He's an expert in this area (ask him how he knows)

Don't relocate the fuel tank.

Oscar

[emerygt350]

That trunk gets super warm. I would do the front as well.

[930cabman]

Think Ford Pinto, rear end collision

BTW: she looks nasty with the off road skins

[Craigers17]

I would leave in up front as well, but since you asked....someone has done it. Not me. If you look through the pics in this link, you'll see this guy's install:

https://bringatrailer.com/listing/1972-porsche-914-28/

[rhodyguy]

With the fuel storage in the stock location, less balance upset as the fuel weight decreases? How much fuel do you plan on carrying? The engine will work plenty hard spinning those meats.

[BillJ]

Sticking it in the rear is bad.

[Front yard mechanic]

open up the hood and put a aluminum cylinder tank in the original spot and show case your baha idea plus ,fill up fast! (IMG:style_emoticons/default/smoke.gif)

[PCH]

Also, if you put the tank in the back, you won't have any place to keep the pizza warm on your way home.

[Bullethead]

Baja 914's are cool, but proper weight distribution is just as important in an off-road vehicle. Maybe even more than a street or track car.

Adding more mass in the ass isn't a good idea... besides the pendulum polar moment imagine how it would affect suspension compliance.

Spend more effort on chassis stiffness and suspension travel instead.

[ClayPerrine]

That is an absolutely terrible idea. The rear trunk is a crumple zone, and you would be putting the gas tank in harms way. Believe me, I know.

And putting the gas tank above the hot engine/transmission is a really bad idea too.


Leave it where it was put originally. If the tank is bad, there are new ones available, or people on here have good used ones to sell.

(IMG:style_emoticons/default/agree.gif) w/ Clay

He's an expert in this area (ask him how he knows)

Don't relocate the fuel tank.

Oscar

This is how I know.



I was sitting still at a light. The car that hit me was doing close to 100mph. I was pushed forward about 50 feet. The hit was hard enough to pop the ash tray and radio out of the dash.

The crumple zone in the back saved my life. And you want to put a gas tank there? If you do, please let me know your name and address so I can take out a life insurance policy on you.

Clay

[Lockwodo]

Clay, I have to wonder about the bag of kitty litter in the back. Was it in the rear trunk when the car was hit, or was that the work of an emergency responder?

[Van B]

That is an absolutely terrible idea. The rear trunk is a crumple zone, and you would be putting the gas tank in harms way. Believe me, I know.

And putting the gas tank above the hot engine/transmission is a really bad idea too.


Leave it where it was put originally. If the tank is bad, there are new ones available, or people on here have good used ones to sell.

Clay, if there was ever a thread that warranted posting "those" pictures, this is it.

[Spoke]

Compared to Clay's crash, mine was a minor dent.

Besides the crash factor, I would think the heat from the engine, transmission and exhaust would not be good for a fuel tank in the trunk. Also there's very little vertical clearance in the trunk.

[ClayPerrine]

Clay, I have to wonder about the bag of kitty litter in the back. Was it in the rear trunk when the car was hit, or was that the work of an emergency responder?

There were two bags of cat litter in the trunk. We had not unloaded them after a trip to the pet store.

Needless to say, we had to go get more litter.

Clay

[SirAndy]

Picture of how it sits right now with UTV tires, for reference

@Mendivil26

What size wheels and tires are you running on there?

I've been thinking about going the Baja route since we're planning to retire down in the islands.
(IMG:style_emoticons/default/idea.gif)

[Shivers]

I understand wanting to keep the front end light for offroad. The tank near the engine could make for a bad day. Maybe put your spare in back to add some weight, so on a launch the front end stays up. You may need to experiment with that...Aw shucks (IMG:style_emoticons/default/wink.gif)

[Mendivil26]

Thank you all for the great responses!
I understand the crumple zone factor is a big one that I think could be potentially solved by caging it properly, but still.. we have the heat issues.
At this point it's too much of a risk for it to be worth a try; it's probably simpler to keep it in front and just replace with new stuff.

@SirAndy , Running 26-9-r14 in the front and 26-11-r14 in the rear. Wheels are 14in diameter X 7in wide.

I tried mounting the smallest BFG KO2s out there (215-75r15) but the front rubbed the inner fender real bad, no turning radius was left, the rears cleared relatively fine.

26.75in diameter is probably the largest diameter wheel you can have in the front without serious sheet metal massaging.

[Dave_Darling]

I've been thinking about going the Baja route since we're planning to retire down in the islands.

You know what surrounds most islands people would retire to?

Salt water.

In Hawaii, pretty much everything made of any kind of metal corrodes into uselessness in a few years. Even "stainless" steel, aluminum, brass...

Imagine the effect that salt spray would have on a 914.

--DD