fuel tank

[Apurv Agrawal]

the rule for the fuel tank specifies that the a permanent fuel level line be marked. filling till this point would make the fuel tank completely full.
wont't it be better to atleast leave 10% of fuel tank volume for airspace above for better venting?
to achieve this, is it possible to have a fuel tank of bigger size and marking a point on sight tube for 2 gallons.

secondly What types of materials are teams using for their fuel tanks?
we are thinking of using MS sheet metal and plating it with tin for instance.
do we require to plate it and if so then can anyone suggest some material.
also, are teams using a fuel level indicator?

any feedback would be greatly appreciated

thanx
Apurv Agrawal
Deianz racing,DCE

[Apurv Agrawal]

the rule for the fuel tank specifies that the a permanent fuel level line be marked. filling till this point would make the fuel tank completely full.
wont't it be better to atleast leave 10% of fuel tank volume for airspace above for better venting?
to achieve this, is it possible to have a fuel tank of bigger size and marking a point on sight tube for 2 gallons.

secondly What types of materials are teams using for their fuel tanks?
we are thinking of using MS sheet metal and plating it with tin for instance.
do we require to plate it and if so then can anyone suggest some material.
also, are teams using a fuel level indicator?

any feedback would be greatly appreciated

thanx
Apurv Agrawal
Deianz racing,DCE

[ANDONI]

You can have the tank as big as you want/need it. The level line must be where the rules say. I recomend using a check valve for the air trapped in the tank.

Material: welded aluminum..as thick as you want it.

We don´t use the fuel level sensor...but i dunno how many uni´s do.

Chao

Andoni Mazeika
www.formulasaeusb.com (http://www.formulasaeusb.com)

[Michael Jones]

This year's tank is titanium. A bit overkill but given that ethanol and aluminum don't work well together, not a bad idea. OUr dyno Al tank just spouted a billion holes around the welds. Takes some time to get to that point, but it happens.

---
Cornell Racing
http://fsae.mae.cornell.edu

[Ben Beacock]

We made ours from sheet steel. My welding wasn't perfect and there were a few leaks so I got it soldered and pressure tested but it seems light enough for us(1st year team).

Ben Beacock
Chassis Design and Technical Coordinator
Gryphon Racing - University of Guelph

[Charlie]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by ANDONI:
You can have the tank as big as you want/need it. <HR></BLOCKQUOTE>

Beware where you get your rules clarification from. http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>3.5.3 Fuel System
3.5.3.1 Fuel Tank Size Limit
All gasoline-fueled cars must be equipped with a fuel tank having
a volume of no more than 7.57 liters (2 U.S. gallons). E-85 fueled
cars must be equipped with a fuel tank having a volume no greater
than 10.6 liters (2.8 U.S. gallons). Any size tank may be used up
to the maximum allowable size. The fuel system must have a
provision for emptying the fuel tank for the purpose of measuring
the tank volume.<HR></BLOCKQUOTE>

In response to your question, I think the rules clarify the sight tube & volume correlation:

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>3.5.3.3 Fuel Level Line
A permanent, non- moveable fuel level line must be located
between 12.7 mm and 25.4 mm (0.5 inch and 1 inch) below the
top of the sight tube. When filled to this level, the fuel system
including fuel lines, filters, etc., must not hold any more than the
maximum allowable fuel volume.<HR></BLOCKQUOTE>

However, for your question about leaving space in the tank for venting, I'm not sure how better it would be, but I am fairly certain it is not allowed, because the rules require the sight tube to be attached to the filler neck.

Of course this is just my interpretation http://fsae.com/groupee_common/emoticons/icon_wink.gif

Good luck, see you all in Detroit http://fsae.com/groupee_common/emoticons/icon_smile.gif

-Charlie Ping
Auburn University FSAE 1999-present

[ArizonaDave]

We got hacked at the tech inspection last year for not having a check valve... So I would say you have to use one for that, and it also solves your air trapped problem...

[Tyler Kuhlmann]

Where are you guys getting your check valves?
Thanks,
Tyler

[Tony K]

Pegasus Auto Racing.
http://www.pegasusautoracing.com/ProductDetails.asp?RecId=899
I've seen some other ones out there, but I like this one because it is quite a bit smaller than a lot of the ones designed for large race cells.

[Moke]

I think the new rules (2005) rules don't have a max fuel tank size. In terms of sealing a tank try rubbing a bar of soap over the leaks it reacts with fuel to seal.

[JadgPzIV]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Michael Jones:
This year's tank is titanium. A bit overkill but given that ethanol and aluminum don't work well together </div></BLOCKQUOTE>

For ethanol/methanol fuel tank, we used, since 2002, welded aluminium with an elastomeric coating inside. This coating is very similar to the one used on the rack in a dishwasher. It is normaly used for restoring old fuel tank.

[jejuu]

hi ..admit that dis is a stupid question.but im very new in this team. hope somebody could help.

how and where should i mount this check valve? from what i understood,only the sight tube (which serves to be as max fuel line), and the check valve serves as to empty the tank to measure the fuel. so it shouldnt be at the filler neck right? n must be at the bottom of the tank?

right? http://fsae.com/groupee_common/emoticons/icon_confused.gif

[Tech Guy]

Jejuu,
Every fuel tank needs a vent line to let air in and out of the tank. Air needs to go in to replace the fuel you use, and air needs to go out sometimes, because the fuel returning from the engine (with fuel injection) is hot and needs expansion space. The check valve has to go in the vent line and is to stop fuel coming out of the vent if you roll the car! It has nothing to do with the fuel drain.

[Peter7307]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Moke:
In terms of sealing a tank try rubbing a bar of soap over the leaks it reacts with fuel to seal. </div></BLOCKQUOTE>

For heavens sake !
Go and buy the proper stuff for this.
Considering this IS a safety issue I am astounded there is any discussion on this point at all.

Lined tanks do the obvious in sealing pinhole leaks when the tank is built and they also stop leaks caused by fatigue cracks during the race when they happen.

The last thing you want is a strapped in driver and fuel dribbling every where near a hot anything.

Pete.

[jejuu]

There a few things that I don’t really understood,

‘Air needs to go in to replace the fuel you use’
Check valve is one way valve right? When the fuel tank is hot, air need to be vented OUT of the tank. When the valve is a one way valve, how does the air suppose to go OUT and IN to the tank?

‘The check valve has to go in the vent line’
Which vent line does you referring to? Or should it be vented out to the atmosphere? Hope you don’t mind to explain more

And one more thing.. When I look for the check valve, they ask for ‘cracking pressure’. My interpretation to cracking pressure is the pressure when the valve starts to open. So, what is the cracking pressure should I use? Is it 1atm? (So that the pressure inside the tank and the atmosphere will be the same and avoid the expansion of the tank?) http://fsae.com/groupee_common/emoticons/icon_frown.gif

This is the link to the check valve supplier : http://www.swagelok.com/search...=/id-10002259/type-1 (http://www.swagelok.com/search/find_products_home.aspx?SEARCH=/id-10002259/type-1)

[Tech Guy]

jejuu,
The check valve has a small ball that seats and blocks the passage of air when the valve is turn upside down.

So, when the car is right side up, air can pass both into and out of the tank. When the car overturns, the ball in the check valve falls down and seats and blocks the hole.

The vent line should go from the top of the fuel tank to the atmosphere. Keep the end of this vent line away from the exhaust and the driver.

Pegasus sell one:
http://www.pegasusautoracing.c...etails.asp?RecId=899 (http://www.pegasusautoracing.com/productdetails.asp?RecId=899)

[jejuu]

ic..thanks for the help tech guy. appreciate it so much http://fsae.com/groupee_common/emoticons/icon_smile.gif

[jejuu]

oh ya.. i saw this checkvalve on pegasusautoracing.com. but i dont have any idea how does it mounted on the fuel tank and how does this valve get connected with the fuel vent line?pictures will be helpful...

one more thing... regarding the filler neck. im thinking on connecting the fuel tank and filler neck with a silicon hose since its a little bit hard to put the tank into the car with the filler neck if they were to be welded together. i wonder what will the judge will say about this..

for the fuel tank..just to check with others on the hole that we need to have on our fuel tank if we are using external fuel pump. the holes are

1. fuel return hole
2. fuel outlet to fuel pump
3. provision for emptying the tank (as per rule)
4. for mounting check valve

er....right?

[Wesley]

Most check valves work fine for venting - it takes a bit of a "puff" to get them to seal off, if mounted in the proper orientation. We've bought ours from Pegasus in the past, and we usually mount the valve straight up for this reason - if you mount it backwards or upside down, you can prevent venting. Done it, and seen the tank bulge under the pressure.

[vkarmwar]

guys what the hell is this fuel line and where do you lace it exactly??

[Rex Chan]

Here is a picture: Melbourne Uni/MUR Motorsports 2011 FSAE car Left side (http://www.facebook.com/photo.php?fbid=10150492125423036&set=a.10150492123373036.375436.559588035&type=3)

See the clear filler neck just above the red cooling hose? The horizontal black line is the fuel level line.

[Jon Burford]

for our fuel (standard shell v-power as in UK competition), we use a "thin" aluminium sheet welded tank, with a clear filler neck section and a horizontal black line for the fuel level.
You should also consider some form of system to stop the fuel moving around so much inside the tank during heavy cornering.