Fuel cell rotary molded vs bladder

[BorkRacing]

I have been looking at new fuel cells and the one which will fit my car the best is a rotary molded (hard rubber) fuel safe. All the other wedge shaped cells are a softer bladder material. Both are rated the same. Is the hard rubber less safe in an incident?

Robby
Zink Z10

[nickal]

I have been looking at new fuel cells and the one which will fit my car the best is a rotary molded (hard rubber) fuel safe. All the other wedge shaped cells are a softer bladder material. Both are rated the same. Is the hard rubber less safe in an incident?

Robby
Zink Z10

For what it is worth: CVAR down here in Texas specifies bladder type fuel cells. I am currently going through
A Lola equipped with a rotomold tank and intend to take it to the next race to get a specific yes or no from the tech inspectors. I will post the result.
Nick L.

[DanW]

I have been looking at new fuel cells and the one which will fit my car the best is a rotary molded (hard rubber) fuel safe. All the other wedge shaped cells are a softer bladder material. Both are rated the same. Is the hard rubber less safe in an incident?

Robby
Zink Z10

Robby,

Have you tried having your existing cell repaired and recertified? I have a cad drawing if you need dimensions for a new cell.

Dan

[nickal]

For what it is worth: CVAR down here in Texas specifies bladder type fuel cells. I am currently going through
A Lola equipped with a rotomold tank and intend to take it to the next race to get a specific yes or no from the tech inspectors. I will post the result.
Nick L.

Well, the CVAR tech guys said the rotomold tank was just fine. Make sure foasm is fresh. and enclose the tank in an aluminium container.
NL

[Rick Kirchner]

The problem with that solution is that you won't be able to race it anywhere else....

[BorkRacing]

Fuel Safe recertified the cell, building new container.
I have a brand new Fuel safe cell that does not fit.

Rob

[Daryl DeArman]

The problem with that solution is that you won't be able to race it anywhere else....

Not sure I agree with you Rick. The GCR states: . "All safetyfuel bladders shall be constructed and certified in accordance with the FIAFT-3 or higher (FT-3.5, FT-5, etc.) or SFI 28.3 specifications" <snip> "All safety fuel cells shall consist of a foam-filledfuel bladder enclosed in a metal container at minimum."


Then from ATL's own site the FIA FT-3 Sports Cell properties specifically refer to the "bladder" as a "Hard rubber all fuel bladder".

[BorkRacing]

It says FIA/SCCA approved on the cell. Can't imagine it a problem as the car I am putting it in previous owner had a only a bladder with no metal container and it passed tech....

Not sure I agree with you Rick. The GCR states: . "All safetyfuel bladders shall be constructed and certified in accordance with the FIAFT-3 or higher (FT-3.5, FT-5, etc.) or SFI 28.3 specifications" <snip> "All safety fuel cells shall consist of a foam-filledfuel bladder enclosed in a metal container at minimum."


Then from ATL's own site the FIA FT-3 Sports Cell properties specifically refer to the "bladder" as a "Hard rubber all fuel bladder".

[Rick Kirchner]

when you said roto-molded I was thinking of those heavy plastic cells. didn't realize there was a roto-molded cell that passed the FIA spec.

[Daryl DeArman]

when you said roto-molded I was thinking of those heavy plastic cells. didn't realize there was a roto-molded cell that passed the FIA spec.

You are on the right path....almost like the JAZ type cheap-o cells or catch cans...just with foam inside and placed in a metal enclosure. They aren't as flexible as your what we think of when we think "fuel cell bladder", but not so rigid that you envision it shattering/cracking if hit with a hammer. ATL calls it "semi-rigid" in their marketing literature.

Personally, I wouldn't use one, but that's likely due to my ignorance about them and the FT3 spec. I would prefer to stick with something that deforms to a large degree with the enclosure.

[Rick Kirchner]

JAZ was specifically what I was thinking about....

[BorkRacing]

You are on the right path....almost like the JAZ type cheap-o cells or catch cans...just with foam inside and placed in a metal enclosure. They aren't as flexible as your what we think of when we think "fuel cell bladder", but not so rigid that you envision it shattering/cracking if hit with a hammer. ATL calls it "semi-rigid" in their marketing literature.

Personally, I wouldn't use one, but that's likely due to my ignorance about them and the FT3 spec. I would prefer to stick with something that deforms to a large degree with the enclosure.

Appears to be able to deform closely to the "other" bladders but at that point you should really be worrying about how much YOU can deform. i have seen all types of fuel cells ripped from PRod cars, both types hold up and both types rip open. Maybe if we didn't use the minimum allowed metal thickness for the containers they would be safer as well.

[BorkRacing]

You are on the right path....almost like the JAZ type cheap-o cells or catch cans...just with foam inside and placed in a metal enclosure. They aren't as flexible as your what we think of when we think "fuel cell bladder", but not so rigid that you envision it shattering/cracking if hit with a hammer. ATL calls it "semi-rigid" in their marketing literature.

Personally, I wouldn't use one, but that's likely due to my ignorance about them and the FT3 spec. I would prefer to stick with something that deforms to a large degree with the enclosure.

Oddly both types of bladders have the same FIA specs. So either the roto-molded bladder is better than suspected or the flexible bladder isn't as good as originally thought.

[Daryl DeArman]

Oddly both types of bladders have the same FIA specs. So either the roto-molded bladder is better than suspected or the flexible bladder isn't as good as originally thought.

Or both...

[BorkRacing]

Or both...

If it was SCCA alone I would worry more...

[Drake]

Any word as to which lasts longer or there ability to handle ethanol?

[BorkRacing]

Any word as to which lasts longer or there ability to handle ethanol?

All cells with FT3 rating are good for 5 years and can be recertified for 2 more. Not sure if the are ethanol compatable but ATL says they are high impact and heat resistant, and balistically self healing. Also they are not plastic as the Jaz cells, but a molded hard rubber, just like that one in your wallet from jr high school!