Fuel tanks
The cars > Developments and changes
One other little thing that seamed to repeatedly cause
trouble over the years hasbeen that for some reason I kept having
issues with the fuel tanks and during the event at Ebbw vale it became
apparent that another fuel tank had developed leaks.
This
was the first fuel tank:
Initially
it was bolted directly to the floor via some pillars to raise it from
the bed to accommodate the sump in the tank.
I
have subsequently learnt that this does not allow the tank any free
movement and subsequently the tank will fail. This is largely due to
the twisting stresses applied through the “ridged” tank during an
event the tank tends to crack along seems and the heat affected zones
around welded joints etc.
Some of the varoius fuel tanks fitted (and failed).
A
latter attempt at fitting the tank involved creating a subframe using
two lengths of aluminium box section and this was mounted through
some rubber mountings (in this case engine mounts) this also proved
to be too stiff and the tank failed
The
staining on the tank indicates that its the welding and the heat
affected zones around welded joints that repeatedly fails on these
design of fuel tanks.
This was the third tank fitted to the car in
the space of a year. Suffice to say I did not replace the tank from
the same supplier after this!
Another
new tank now resides in its place.
This
new tank uses straps to secure it rather that the brackets welded
directly to the tank. In this case the tank sits on a rubber mat to
act as an insulator and facilitate some degree of flexibility whilst
retaining the tank securely in place. Initially I used some straps I
made myself from strips of aluminium sheet, latter these where
replaced using the same style of straps that are used to secure gas
tanks in the rear of cars or vans, this works a lot better as there
is more adjustment available on the latter straps.
N.B.
The tank MUST always be electrically earthed to the body of the car
to avoid the risk of static or electrical discharges creating sparks
etc.
So
far this appears to have reduced the stress loads and is proving much
more reliable.
And finally;
To allow the fitting of a spare wheel carrier to be able to enter the 2018 Welsh Hill Rally (our first), the tank and battery box along with all the fuel pumps filters etc. have been relocated in the rear of the car.
