Rule book specs

[Stuart]

Anyone know what the minimum required thickness is for aluminum to be used for a fuel cell? I'm making my own fuel cell but my NHRA rule book doesn't have a wall thickness in it?

Also, would it be better to run my battery cables in through the interior or on the bottom of the floor? Obviously I'm mounting my battery in the trunk. ;D

[maritimedragracing]

If memory serves me correctly the minimum thickness for aluminum is .032. About all that's in the IHRA rulebook is the following:
When permitted by class regulations, fuel tanks located outside body and/or frame must be enclosed in a steel tube frame constructed of minimum 1 1/4-inch O.D. x .065 chrome moly or .118 mild-steel tubing.
All fuel tanks must be isolated from the driver's compartment by a firewall, completely sealed to prevent any fuel from entering the driver's compartment. All fuel tanks must have a pressure cap and be vented outside of car body. A positive-locking screw on fuel-tank cap is
mandatory on all cars. Insulated fuel tanks prohibited. When used, fuel cells must have a metal box protecting the part of the fuel cell that is outside of body lines or trunk floor, excluding hose-connection area in rear. Non-metallic fuel cells or tanks must be grounded to frame.

[Stuart]

Yeah, thats what the NHRA book says too, but it really doesn't spec a thickness for a fuel cell? I was going to make it out of 1/8" aluminum and TIG weld it. Got any idea's where I can buy the proper type of pressure cap? I was going to make up a small aluminum pipe to the gas door hole for a vent, is this ok?

[maritimedragracing]

1/8 aluminum is perfectly acceptable for a fuel cell. If the location of your fuel fill door is higher than the top of the cell it could cause increased evaporation of the fuel. Most fuel cells are vented with an inverted "U" bend from the top of the cell down through the floor. Also the "pressure cap" referred to is simply one without a vent hole.

[Mitch Bonnar]

I suspect the lack of specification is due to it not being anticipated that one would build their own tank. It appears to be geared around an OEM tank in OEM position or in the case of a remount, a certified tank secured and installed as per the above specifications.

BTW - The vent to the outside must have a rollover check valve installed to prevent fuel spillage.

[maritimedragracing]

Good point about the rollover check valve. It is likely that safety foam should be installed too. Again, nothing in either rulebook helps clarify the application. Like Mitch said - very few people build their own tanks.

[Stuart]

Maybe I should just break down and buy a cell.....foam and rollover check balls....the price is climbing...LOL....I was getting the aluminum and TIG welding for free. ;D....I don't understand your description of the "U" vent line?....I was just trying to save a little $$$.....might be easier to just spend some.....I've already got some smokin deals on some engine parts on ebay, all new but one part and most are close to 1/2 the cost of new in Canada...

[sam]

Stu, Have you checked into prices of fuel cells?
You are building this car just for the track only,
buy the pics and comments I have seen on here
already. Believe me stu a 2 or 3 gallon fuel cell
with foam will not cost you as much as you think.
And I know what it is like to build on a budget
been building one for 5 years and still not quite
finished yet. Hopefully get it there for last race.
Have you tried places outside of HRM for prices.

[Stuart]

I get my deals on ebay....I won an almost new Sunpro black face 5" tach with LED shift light for $28.77USD and a new 351W Comp Cams 280H bumpstick for $56USD...that's $70CDN for the cam, retail up here is $169.95CDN plus 15% taxes...another good deal and the .512 lift should work good with ported factory heads and stealth intake we just bought too.

Its not a radical cam, but for season one the goal is reliability and to work out the bugs, the more serious HP will come in season 2 and then the 280H might go in my 63 Merc. I also got a brand new Weiand stealth 351W intake for $212cdn with shipping included. I've been watching a few fuel cells on there....I think I'll just avoid the headaches and buy one.