Rear Firewall & Fuel Cell

[PaulFinch]

Hi All,

I want to fabricate a firewall for my Elan S4 coupe.

As I don't imagine scrutineers will accept the hardboard parcel shelf and backboard, I am considering 1.5mm ally sheet or carbonfibre sheet.

I would welcome any tips from anyone who has constructed a similar item.

Is it as simple as making a template, cutting the aluminium, riveting together and screwing into fibreglass?
Has anybody bonded in matt to make up a permament solution?

I'm also after opinions on ATL style fuel cells. It has always bothered me that the rear crash structure of our cars is made up of a fuel tank. I am thinking of replacing with something like a standard 8 gallon rectangular foam filled tank, centrally located away from the rearmost section of the boot.

Any hints, thoughts or pictures are gratefully received!

Paul

[rgh0]

Hi Paul

This is what I have done with my Elan. Its a standard 30 Litre ATL Fuel cell in a stainless steel enclosure fixed to the floor and front of boot with about 6 bolts and aluminium plates on the other side of the fibreglass Yes the aluminium sheet was easy to make up and screw to the fibreglass around the parcel shelf and bulkhead.

About 3 months after I first rebuilt my Elan back in 1981 I was run into the back off on the road and had a large dent put in the fuel tank - fortunately it did not rupture. When I went full circuit racing in 1990 I put this arrangement in place after the scrutineers were not impressed with the fibreboard firewall

cheers
Rohan

[bill308]

Are the bags in the standard fuel cells replaceable?

Bill

[rgh0]

Hi Bill

The ATL cell uses a special red flexible moulded plastic material for the cell. They provide you with plans to make the steel container for it that I had made up in stainless by a sheet metal fabrication shop. I presume you could buy a new standard cell from them and swap over the hardware if you wanted to.

cheers
Rohan

[bill308]

Thanks Rohan.

Bill

[Certified Lotus]

My Elan came with a fuel cell installed in the boot next to the spare tire. It's more than 15 years old and is no longer good as the foam isn't designed to last that long (note the size of the fuel filter) so I am replacing it with a new OEM size aluminum tank this winter. Photo is to show you the install (not done by me).