Fuel Tank

[deezee]

I wanted to make my fuel tank in some 2mm aluminium sheet I have in the shop. Its going to be a breeze to fold it on the press, it just means digging out the AC set to TIG it up.

Is there any reason the tank is the size it is? I mean can I make it taller, to hold more fuel. I figure by making it around 10mm narrower (to assist in fitting) and around 75mm taller, it would hold another 10 litres of fuel.

Can anyone see any problems with this?