Fuel Tank Removal

[Steve_Lindford]

Can both fuel tanks be removed upwards after the engine has been removed?? - Twincam.

Steve

[TurboFource]

It is my understanding they have to come out the bottom or up with the body if you remove it....

[dakazman]

  X2 on what turbo said!

   My S2’s came out the bottom. It had a hole cut out when I got the car. My firewall was in sad shape and I took it out . When building it back up I made it so the wall can be taken down and remove the tank from inside. I also repaired the hole.
  Just food for thought if you are thinking of working on your firewall and it might save you some time.
Dakazman

[Grumblebuns]

Agreed, I looked at the tanks when I had my engine out and no way will the tanks come out the top. They will hit the top of the body before you can tilt the tanks in to pull them out.

 

[Steve_Lindford]

OK thanks for the info. Thinking I should replace the coolant transfer tubes and I thought I could investigate the fuel tanks at the same time. I will have a think about the firewall. It is non standard - or at least covered with a sheet of aluminium. I have wondered if a detachable firewall might help with replacing water pump - not that is anything I am thinking about...

Thanks - Steve

[BDA]

It would be a lot easier to cut a door in the firewall for access to the water pump than to make a detachable firewall. On the other hand EuropaTC has written up how he does a water pump with the engine (and complete firewall) still in the car (http://www.lotuseuropa.org/LotusForum/index.php?topic=4128.0).

[Steve_Lindford]

I presume that undoing the tank bolts I will require access from wheel arch - through the small covers - to the bolt heads. I cant see how there is any hope of turning a spanner on the nuts. It seems quite likely I might have to cut the bolt heads off... I havent committed myself to this job yet as I have gearbox off and all wheels - so I can't move the car to a pit to lower the tanks  out. I may think about jacking the car up high...

[BDA]

Once you take the wheel arch “closing plates” off, there is (or was for me) enough room for a wrench - probably a ratchet wrench. I don’t remember having any trouble at all. In fact, I had my tanks made for me and I put my new tanks in twice. Don’t let it scare you.

On the other hand, let propping your car high enough to take the tanks out scare you enough to be VERY careful about it. IIRC, my body and frame were separated when I got my tanks out.

[Dilkris]

  With the "closing plates" off the 4 bolts per tank are easily accessibly - you will then see how easily they shear off in the captive nuts welded to the tank supports....  (Well mine did - 4 out of 8  )

[Steve_Lindford]

Thanks for the info re the closing plates. The more I think about all this - the option of restoring and modifying the firewall to remove the tanks seems more appealing. I don't have the space or inclination to remove the body to gain access. Is the rear panel behind the driver 'solid' fibreglass between the sound insultion and interior panel?? Do you think a removable access panel would affect any of the structural strength of the body??

The fixing bolts shearing off would be the best option!

[BDA]

Replacing the firewall is a pretty common mod. I've heard some have used marine plywood and I think I remember someone using aluminum honeycomb! I'm sure there are lots of options. I didn't take mine out and instead glassed the engine side. I don't recommend it. It's really messy and complete replacement is probably a better option but certainly a lot more work.

Without knowing how rigid the firewall is, I can't say how much structural strength it provides. My guess is that it doesn't actually provide much but it's only a guess.

I'm not sure how this panel is supposed to work. I suppose if you took the firewall out, that would make access to the gas tanks a lot easier (keep in mind that the area of the rear window is not really part of the firewall so that might be in your way but I'm not sure.

As I write this, if it is really impractical to put your car on a two post lift or over a pit. you might need to consider replace your firewall. unless you think you can  safely lift the car three feet off the ground.

[JR73]

The original firewall offers nothing to the structural integrity of the shell - it insulates you from some of the sound, heat and fumes from the engine bay and that's about it. Give it a good soaking and it has about the same integrity as wet cardboard!

Flat fibreglass sheet around 5/6mm thick works pretty well and you only have to glass around the edges and over any joints you may need to put it in place.
Alternatively plywood works ok too - the very last Esprits still had plywood bulkheads (again, adding nothing to the structural integrity) that can be removed by hand without very much force (yup, experience!!).

As for the fuel tanks, the hole underneath was cut at the factory in order to install the tanks - it was pretty rough to start with and over time it won't have improved, especially with rough jacking etc. Mine was supplied new in kit form and the hole was already cut out.

[Gary t]

I don't think the car has to be unreasonably high in order to remove the fuel tank. I had my S2 on stands to do suspension and drive shaft work and was able to  remove and replace the fuel tank.  I probably had 14 or 15 inches under the body.  Car seemed safe and secure on 4 stands.

[gideon]

Mike Kimberley posted on Facebook to say that the firewall is structural.  I know he argued with ACBC about the choice of material.  Chunky won the argument and they used LDF, low density fiberboard, or something very similar.  Apart from its tendency to disintegrate when wet it actually has some nice properties for the job.  It's cheap, light, it's good insulation and it's somewhat stiff.  It'll even take a little while for a fire to burn through it.

There is little to no fiberglass over the LDF, except at the edges.

I will replace the firewall in my car with a sandwich panel of some sort, to keep the weight down.  I'll look for a compromise between price, weight, noise and heat insulation, fire resistance and structural value.

[BDA]

I don't think the car has to be unreasonably high in order to remove the fuel tank. I had my S2 on stands to do suspension and drive shaft work and was able to  remove and replace the fuel tank.  I probably had 14 or 15 inches under the body.  Car seemed safe and secure on 4 stands.

Well, you got me to measure mine and was a bit surprised to see they are about 22" not counting the neck. That implies that you'd only have to raise the car about two feet off the ground rather than the daunting three feet I suggested. So the car would only actually be about 1 1/2" higher than it sits at the curb. That sounds very doable so Steve (and others), take note of my upgraded position!