Just thought I’d share this project I’m working on for a buddy and myself. Seeing what everyone thinks.

With headaches of having different tech’s at my local tracks have their own personal opinions about how the nhra rule book is written. It’s seems they pick and choose what passes and does not pass for stuff that is clearly in spec of the nhra rule book.

For the tech’s personal opinions on sealed firewall access doors, It led me to make a “visibly dummy proof” sealed access cap for my fuel cell firewall.

With locating my fuel cell in the spare tire carrier area. As you all already know the fuelcell has to be sealed 100% from the drivers compartment.
So to access the top of the fuel cell for filling fuel. I came up with this solution which is large enough to give you plenty of room to reach the fuel cell cap with ease.

The base will be siliconed and riveted to the aluminum sheet metal and the cap will be sealed to the base via an 1/8” dia. O-ring groove just before the shoulder. I still need to counterbore the threads on the base an 1/8” for the oring seal surface. My lathe has been tied up with current work so I have yet to find time to start machining the caps.

After running this idea by my local nhra director, he clearly stated I should not have any issues during tech inspection.

Allways good to think outside the box, im having to redesign something aswel for racing. They are pretty strict everywhere on fuel, alot also worry about vent valves if you go upside down, is this something they worry or care about?

ec17pse said:

Allways good to think outside the box, im having to redesign something aswel for racing. They are pretty strict everywhere on fuel, alot also worry about vent valves if you go upside down, is this something they worry or care about?

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Yes, the nhra are very strict when it comes to anything dealing with fuel, you have to run a rollover check valve and a loop in your fuelcell vent tube and of course it must be vented outside of the vehicle.

So your cap is closed and you wont use a check valve inside that no, the vent will be the only check valve. I think they cant say its not safe now, cover every angle when doing the project, should be good once done, keep this post updated with its progress

ec17pse said:

So your cap is closed and you wont use a check valve inside that no, the vent will be the only check valve. I think they cant say its not safe now, cover every angle when doing the project, should be good once done, keep this post updated with its progress

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As stated above this a sealed firewall access cap that will attach to my fuel cell firewall, it’s purpose is to seal off the fuel cell from the drivers compartment but still have access to the top of the fuel cell.
Your question about fuel cell venting is something they are also strict on. My last response explained what the requirements from the nhra are.

@ec17pse i hope my lathe will be free next week so I can make some more progress and finish the caps

GsxJon said:

As stated above this a sealed firewall access cap that will attach to my fuel cell firewall, it’s purpose is to seal off the fuel cell from the drivers compartment but still have access to the top of the fuel cell.
Your question about fuel cell venting is something they are also strict on. My last response explained what the requirements from the nhra are.

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Yeah sorry if i asked again i was just about to go to bed and i might of not fully sunk in your reply, sorry about that,