Petrol tank size/volume & clearance

[kevchard]

Are there any Carol Vordemans or maths gurus out there? I am wanting to know if i make a petrol with the following dimensions, what would the volumetric capactiy be in litres/gallons.
71cm wide, 29cm high & 40cm deep.
Also, how much room do i need to leave between the top of the petrol tank and the inside of the bodyshell?
Cheers

[Grease Monkey]

.71 x .29 x .4 = 82 litres

82 litres / 4.546 = 18.2 gallons

[stevee8]

Multiply all three dimensions to give volume in cubic centimeters (cc) then divide by 1000 to give litres = 82.36 litres.

You didn't say whether the dims were internal or external so you might need to make an adjustment or two but the concept is the same regardless.

There should be enough clearance between it and the body to avoid any rubbing and you may need to take account of the sender unit and filler neck.
:thumb:

[Almac]

Damn - got there before me Adrian! Having just done the same calculation, I concur!

Alan

[dinosoar]

Thats a lot fo fuel!
Make sure you have good baffles. 1 litre of water is 1kg so fuel won't be far off that
80 odd kg's
I made my last one to just over 70 litres and I thought that was big.

Andy

[kevchard]

Thanks everyone. I am worried about how much room i will need to allow for the fuel filler to go into the top of the tank.
I want the petrol cap in thr centre of the tank.
The dimensions were o/d not i/d, but i'm sure it wont make a heap of difference.
Cheers again

[kevchard]

After reading comments on the large litreage (if there is such a word), i have decided to make my tank smaller. A little over 14 gallons should be ample.
Can anyone suggest how much of a 'stub' should protrude above the tank for the fuel filler?
Also is 80mm clearance enough between top of fuel tank and inside of car?, or do i need to leave more room for stub ends and rubber pipe?
1 final question, if i am having the fuel filler in the centre of the car (eg not on the rear wings), what dimensions can anyone suggest as to avoid the soft top (that we do not yet have). eg on a cortina / sierra viper, how far is it to the centre of the fuel cap to the rear of the cockpit of the car (parcelshelf area, if it had one)?
Cheers

[Paul B]

Kevin

If you are going to Stoneleigh, measure up one of the Pilgrims for the placement of the filler cap.

With regards to the gap between the tank and the body, the stub on tank should be around 40mm to allow for the jubilee clip etc. However, make sure you leave enough room to get the rubber pipe in and two clips, one for the fuel tank and one for the bottom of the filler cap.

Unless your hands are very small, you ought to leave around 100mm to actually get in to do the clips up.

Hope this helps.

Paul

[FMAN]

Don't forget that you might need to fit/remove the tank with the body on and the body curves downwards toward the boot opening. I had to reduce the size of my Pilgrim tank because of this. There was plenty of room when it was in place but impossible to get in/out.


Neil

[route66]

Also, I'm assuming you are not going to simply weld up a rectangular box.
Free surface effect of the fuel sloshing from side to side when cornering can upset the car's balance and feel.

To alleviate this, you will need to weld in parallel baffles in both the side to side plane and (to a lesser degree) the fore and aft plane. These will need to be cut at the corners to ensure adequate draining and venting between the baffles.
The baffles also help to support the side walls of the tank against the weight of the fuel distorting the tank. Don't forget to leave space for the fuel level sender to swing over it's full range without fouling.

Just think of the construction of the inside of the tanks of a supertanker and you won't be far off.

Steve