Fuel tank position

[TorAtle]

I have a LHD K-series car. With the engine being canted over, the exhaust system hanging out and my seating position where it is I have most of the weight on the left side of the car.

 

In front of the passenger there is pretty much nothing exept for the inlet system. I have no real use of the extended footwell.

 

The fuel tank - at up to 25kg when full - is at the rear of the car. Not exactly the ideal position for that much weight. I think I would like to have at least 10 litre fuel capasity, and I think there's room for a 3 gallon tank if I remove the extended footwell.

 

So...should I be worried about having a fuel tank right next to the engine? The fuel lines would be very short, that's a plus, but what about the heat from the engine? Or the fact that the ingition system would be close...

 

Any thoughts on this?

 

[Fred]

WHY would you wan't to do such a dangerous and silly thing

 

 

[TorAtle]

Weight distribution. I tried to explain why - I've got most of my weight on the left side of the car.

 

Smaller tank, no fuel neck/fuel cap plus shorter fuel pipes would probably amount for a kg or so on its own, but the main thing is to get an average of say 10kg located centrally in the car, and in my case, also on the right side. A flat floor setup is a good thing but it's better to move things around if possible.

 

A MR2 I once owned had the fuel tank between the seats in the transmission tunnel. A Ginetta I had a year ago had the engine in the rear and the fuel tank up front. Most cars have engine in front and fuel tank in the back. Is it just a case of putting the fuel tank where you have room for it? Does it need to be as far away from the engine as possible? Should it be placed in the middle of the car so the chance of hitting it in the event of a crash is small (surely that can't be the case in the standard Caterham setup)?

 

Well I don't know. I'm only asking for some input. One thing though, because Caterham decided to but it there isn't a reason good enough.

[Chelspeed]

Due to the light weight and incredibly good brakes on a Caterham a lot of accidents are being punted up the ar*e by a muppet tin top driver half asleep listening to radio 2 with his flat cap on. So in this case the most silly and dangerous position for the tank is acting as a crumple zone in the weakest part of the car, ie behind the de dion tube.

 

So I think Fred is being very unfair with his comment. You are right to question the location. How much fuel do you need? Is it still roadgoing? I've got a 6 litre tank which is good for 20 road miles or perhaps a 3 mile sprint, probably impractical for a car that's also used on the road....

 

My weight distribution was biased to the right (ie driver's side, like your's) but also biased to the front (big heavy Vx engine before anyone else dives in....). So my tank is in the far left corner of the boot. What's your front to rear distribution like?

 

[Stuart Faulds]

Under-bonnet fuel tanks are very common in Stock-hatch rallycross cars if it's any help? In the Peugeot 205 it's not unusual to see a half-size battery fitted with a small tank taking up the remaining space (the battery tray sits over the gearbox).

[Fred]

Sory if my reply was blunt.i can understand if the car is for track use.but on the road i just feel it's a bomb wating to go off . i also feel you need a bit of weight at the rear, when i read your post the thought of the tank in the engine bay sounded scarier than the rear .if you feel you need to do this i think one way would be a boat fuel tank, you could easy cut a hole and fit the pump and have a quick release fitted in the passenger footwell this way you would still have the option to use the rear tank if necessary.

 

 

[TorAtle]

Chelspeed,

 

apart from longer journeys which I no longer do, I never fill it up more than half full. 10-12 litres would no nicely. It is a track day car but also for short blasts on the road.

 

I'm not at home this week, but IIRC the front/back weight distribution is 47/53 in that order. That's with no driver, so all in all it seems like a very good idea to get rid of that rear weight and put it where I need it.

 

Demon Tweeks 2002 catalogue, page 200, item 6 - 3 gallon, 340x200x200 would be about right, but I need to get home and get the ruler out to see if it fits. AH Fabrications, "alu and titanium welding specialist as used by WRC teams..." as sales blurb says. 95 pounds+VAT. Any comments on their products?

 

Worst case - a big shunt where fuel tank is squeezed and raptured between hot engine and RHS chassis members. A big boom or "just" a major fire?

 

 

[rj]

The biiig boom is a Hollywood thing, which has nothing to do with real life. Petrol in a sealed can will not just explode as the content will be saturated vapour, and hence not enough oxygen present. The troube usually comes when there is a leak that catches a hot surface. Should that happen, and the tank is heated, will the tank normally open in one of it's weldings. That is of course if the tank has not been too well made... Therefore would I personally prefer a tank which is not too "bulletproof"

 

Anyway I wold not like to be in a burning car. It is a very hot experience.

 

 

rj - ex fireman