Reserve fuel tank

[Colin McKay]

I want to enter a 1 hour race but I'm pretty sure my existing tank will only hold enough fuel for 50mins. Does anyone know if it's permissible to carry a small reserve tank and if so what would be the best arrangement for fuel transfer?

[MGDavid]

2 tanks no problem (Ian H did this on his Sprite for the Spa 1 hour), 2 separately switched pumps Teed into the main feed pipe will be OK as long as the non-return valves work.

[terence]

Or just the one 'T' between both tanks and retain the single pump.

[MGDavid]

Originally Posted by terence bower

Or just the one 'T' between both tanks and retain the single pump.

surely only IF they are mounted on the same surface AND are the same height ?

[GORDON STREETER]

Simple. . I've done this for years, just run a smaller tank above the main one and run the pipe from the higher tank into the breather of the lower one.
Very simple and effective and has never given me any trouble.
At an abroad meeting years ago, I lashed up the radiator header tank off my Trannie. FIA approved

[Al Weyman]

Interesting, small capacity has held me away from doing some events, I may look into this more. Can I mount a 2nd tank inside a hatch back if properly covered?

[terence]

Why not? Very simple thing to do,as Gordon has said.If its covered properly in Ally sheet,you should have no problem's.

[Al Weyman]

Would it be legal to have an aperture held down by Duez (spelling) fasteners to access the filler cap?

[Tim Falce]

Originally Posted by Al Weyman

Would it be legal to have an aperture held down by Duez (spelling) fasteners to access the filler cap?

Don't think it's a problem, a mate of mine used to use them.
BTW they are Dzus

[Al Weyman]

Right, would need some figuring out how to get the fuel in then!

[Tim Falce]

Originally Posted by Al Weyman

Right, would need some figuring out how to get the fuel in then!

Sorry Al, I mis-read your word thinking it you'd written "would it be illegal"
They would be fine to use although maybe the ones with the D rings would save having to find a screw driver every time you fill up.

[Al Weyman]

Good nice one as I have a nice little space where it would fit just fine.

[GORDON STREETER]

The way I pipe it up means that the lower tank filler cap must be absolutely leak proof, and you have to have access to the lower tank so you can fill it up to start with. Hey Al do you remember when the twin tank cooper S was the car to have, if you parked in on a slope with one tank lower than the other you would loose a few gallons out of the lower filler cap.

[GORDON STREETER]

http://www.flickr.com/photos/1634503...12340/sizes/l/
You can see the other tank in this picture. I had to use a fair bit of Tcut to get this scratch out of the old girl after someone used me as brakes !

[Al Weyman]

Originally Posted by GORDON STREETER

The way I pipe it up means that the lower tank filler cap must be absolutely leak proof, and you have to have access to the lower tank so you can fill it up to start with. Hey Al do you remember when the twin tank cooper S was the car to have, if you parked in on a slope with one tank lower than the other you would loose a few gallons out of the lower filler cap.

No I was a flash git, I had the S-Type Jag with twin tanks!

[Colin McKay]

Thanks for the comments chaps, looks like I'm going to try to piggy back a spare tank and gravity feed through the breather. This should work so long as the sender on the lower tank is sealed more efficiently than at present. If that doesn't work I'll have to put a new feed on the existing tank with a tap on the outlet of the extra tank so it can be opened at the pit stop and drain down.

[Tim Falce]

I assume you will be pumping into the spare tank as I tried to gravity feed swirl pot and found the breather wasn't large enough to cope with the fuel flow needed and had to fit an extra pump.

[GORDON STREETER]

Originally Posted by falcemob

I assume you will be pumping into the spare tank as I tried to gravity feed swirl pot and found the breather wasn't large enough to cope with the fuel flow needed and had to fit an extra pump.

I've personally not found any problem with this if you connect it directly into the lower tank breather with the same size pipe as the normal fuel hose. OK I'm aware that as the lower tank hasn't got a breather the fuel won't run into it until the pressure drops, but as the fuel goes down it is replaced from the top tank.
That's why I said you must fill the lower tank up first, I then fill the top tank and slacken the lower filler to get rid of any air.
I use the lower one for short clubbies and as the empty top tank weighs sod all I leave it there all the time.
If you wanted to, you could still use a breather on the lower tank as long as it was extended above the top tank.

[Colin McKay]

Given the ruckus on other threads ref interpretation of the blue book I'm almost afraid to ask this, but I can't see if rollover valves are mandatory, although obviously desirable. Any clues?

[GORDON STREETER]

The best thing to do is forget all about motor racing and come and chill out down in Mojacar, as the powers that be are making it more expensive all the time.
Several years ago I had a bit of a run in with a not very friendly scrute over a trivial thing that made no difference as to safety. and if I hadn't been paid by my sponsors for the years racing I would have walked away and never bothered again

[terence]

Originally Posted by Colin McKay

Given the ruckus on other threads ref interpretation of the blue book I'm almost afraid to ask this, but I can't see if rollover valves are mandatory, although obviously desirable. Any clues?

In a word? Yes! I doubt that you would get through scrutineering without one.

[Tim Falce]

Originally Posted by Colin McKay

Given the ruckus on other threads ref interpretation of the blue book I'm almost afraid to ask this, but I can't see if rollover valves are mandatory, although obviously desirable. Any clues?

Originally Posted by terence bower

In a word? Yes! I doubt that you would get through scrutineering without one.

In another word No.

Originally Posted by Very fragmented and contradictory Blue book

72. Tank fillers and caps must not protrude beyond the
bodywork or be situated within the Driver/Passenger
compartment. The caps must have an efficient locking
action to reduce the risk of opening during an accident
and to ensure closing after refuelling [108-109].
73. Air vents must be at least 25cm to the rear of the
cockpit and must be designed to prevent the escape of
fuel should the vehicle be inverted. It is recommended
that a non-return valve is incorporated in the vent system

Unless of course you can show me another section the contradicts this.

[Colin McKay]

Originally Posted by falcemob

73. Air vents must be at least 25cm to the rear of the cockpit and must be designed to prevent the escape of
fuel should the vehicle be inverted. It is recommended
that a non-return valve is incorporated in the vent system

So how on earth can I prevent the escape of fuel without a non-return valve? I'm not trying to be deliberately awkward about this but the new arrangement is only for 1 race and the rollover valves I've found so far will double the cost of the installation. The existing valve is incorporated in the original tank and can't be transferred to the additional one.

[morninggents]

Originally Posted by Colin McKay

So how on earth can I prevent the escape of fuel without a non-return valve? I'm not trying to be deliberately awkward about this but the new arrangement is only for 1 race and the rollover valves I've found so far will double the cost of the installation. The existing valve is incorporated in the original tank and can't be transferred to the additional one.

If your plastic or rubber tube from the breather pipe is coiled several times this should stop any fuel escaping if you roll.

I suppose, on a lighter note, you need to estimate how many times you will roll to decide how many coils to put in the breather tube.

[Tim Falce]

Originally Posted by Colin McKay

So how on earth can I prevent the escape of fuel without a non-return valve? I'm not trying to be deliberately awkward about this but the new arrangement is only for 1 race and the rollover valves I've found so far will double the cost of the installation. The existing valve is incorporated in the original tank and can't be transferred to the additional one.

I think I paid about £25 for my valve then there's VAT and postage, alternatively as was said above put a few coils in the breather pipe and make sure the end is higher than the tank.