mystery manufacturing process (MGB battery cover)

[Moderator]

You know the five 1/4-turn fasteners on the thin steel battery box cover for a chrome-bumper MGB? How did MG install them there? Somehow they made the steel panel shrink around the pins so-as to retain them without any sort of circlip, right? How?

I have a spare cover. I have a nice flat piece of scrap aluminum the same size. I want to transfer the fasteners over for a modest weight reduction... but I haven't figured out this little trick yet. I'd rather not have to add circlips or substitute regular Dzus fasteners.

[flitner]

To my recollection the hole is stamped out and dimpled, the fastener installed and the material pressed flat, closing the tolerance of the hole. We use a similar process on the package car floor pans.

[TKMad]

They are installed with a grommet, which is then crushed with the installation tool.  Pretty easy.

http://www.southco.com/product/class.aspx?cid=7564

[Moderator]

Thanks for the tips.

I decided to make an aluminum battery box lid today, and I'm pleased with the results. The only expense was my time. I didn't check it, but it was certainly less than an hour.  I had found a pristine piece of aluminum in a trash bin, and I already had a beat up old steel lid in my spares collection, so out-of-pocket expense was nil. I'm sure there must be a hundred equally easy ways to eliminate eight ounces from an MGB... and I'll need more of them to get to my goal (<2000# wet.)



A 9/32" drill bit will make the five holes you need... but if you have a Roper Whitney style punch it'll make burr free holes (at least in four of the five required locations.)  I used the tapered section of a center punch to flare the holes, and for a mandrel I used a rubber bushing. Finally, to flatten out the flare and capture the quarter-turn fastener I used a 5/16" deep well socket.

[mowog1]

Nice job, Curtis.

Did you think about rolling any beads into the aluminum sheet?

You could save over 6 pounds by not carrying that extra gallon of gasoline around with you.

<grin>

[Moderator]

Did you think about rolling any beads into the aluminum sheet?

Beads would reduce panel vibration and thus make the car a little quieter. I have to keep in mind the unique character of my car! (Seriously,  I don't own a bead roller so I would have had to do the job with hand tools. In the meantime, it's installed. I'll probably go back and add a thin rubber seal.)

I plan to install an in-tank pump as part of the EFI system, and the pump will include a better fuel level sender. Maybe then I'll loose that 6 pounds.

[ex-tyke]

.....a better fuel level sender....

I installed a new printed ceramic board type fuel sender (purchased )from the MGOC) last fall and I'm very happy with the accuracy of the unit - much better than the original MGB  design circuitry.
MGOC part number is AHU1027Q.and is reasonably priced. Sender is appropriate for '65 thru' 76 vehicles.