Just wanted to give a update on traveling with Duel tanks, It is awesome. Just completed my third big trip to mini meet East, a 600 mile one way trip. Did about a 1,500 mile trip back in April and a few in between. Not having to worry about Fuel is extremely nice. Only stoped twice for Fuel each way for MME and it saved a ton of time. Didn’t need to worry about getting Fuel every chance I had and it was very nice, worry free. 

Thanks to everyone that help with the advice.  So glad I did this

"WRONG AGAIN."
If you'd bothered to actually go look at the site posted by TK, you'd see the measurements are taken from body seams, NOT THE GROUND! (I'm never going fishing with you!). Also Alex Issigonis had nothing to do with the original Cooper S right side tank location. That would have been John Copper and company. I doubt you'd understand, but a template is a much more accurate way than measuring with a tape of reproducing or mirroring for cutting and drilling. Cardboard is cheap, available material for making a template for single use.

Exactly, not a mirror image,, but the issue and the goal is to make both holes at same height from the ground vertically and center horizontally in referrence to the left gas cap, you dont want the cars behind to see one gas cap is higher than the other, it will look like a sloppy and lousy job and they end up blaming Alec issigonis, it’s not fair for sir Alec to get the blame for not using a measuring tape , measuring it from the ground( and be called dumb), and rather used a piece of cardboard to get the center. I dont see the logic in using a cardboard to be honest.

The right side is not a mirror image of the left. See below for correct measurements.

//www.ausmini.com/forums/viewtopic.php?f=2&t=84662&p=932763#p932763

A couple of  posts suggested measuring from the ground, which is the dumbest idea I've seen here lately. Too many variables - uneven floor, different tire pressures, unequal suspension, different loading from side to side. I think these guys are the type who'd mark a good fishing spot on the side of the boat.

Not to bad.  Just a bunch of measuring.  

what is the cardboard for?????  to copy the round hole? no you don't need a cardboard.   Get a measuring tape.  Measure from the ground up to the center of the gas cap (left side).  then go to the right side and do the same measuring and mark the center with an x or cross. From that cross, hit the center with a philipps screw driver to mark where you will start to drill, using a metal cylinder hole drill bit.  Measure the diameter of the hole as well of course..then start drilling. And don't forget to paint the SIDE of the hole (not the hole itself) with primer paint so as not to start a rust.   good luck!






i'm asian... like you, i'm smart too.

Congrats, how did you make out with the mounting kit??

Sorry about the little hijack,

PS I always thought a second tank in a Mini was a good thing but I used to drive mine flat out as much as possible!

Thanks everyone for your help.  I took what everyone said and gave it a try.  I used cardboard and tape and did a ton of measuring. I have the left side tank out already so getting the measurements wasn't to bad. I flipped my template over and taped it down.  I remeasured it back and forth.  I cut the hole a tad smaller like one person said then sanded it larger as I needed.  I test fitting the grommet with the tank and looks like I got lucky and it fits.  

14 years...we no longer live there as the gummint decided to build a highway (South Fraser Perimeter Road or Hw17 if you prefer), took our house and gave us your tax dollars in return.

Now live in Tsawwassen.

Foolishly got back into Minis but am looking at putting a Vtec (yes, I know, horrors!) into a very clean and solid MG 100.

Probably never will though...

Awesome to hear from you! That trip had foolishness from every angle. I got out of Vancouver before the storm really hit, made it to Bobb’s, slept, and then managed to keep ahead of the road closures all the way through the Rockies. Between Golden and Lake Louise there was no other traffic, and when I came upon a construction crew they all stopped and cheered as I rolled on past them.

That was 14 years ago already. Wow.

I have never read such piffle in my life.

Nice to you are still around mur, and still installing recently assembled drivetrains the day before a long trip! Some things/people never change.

Haven't done such silliness in decades, though I would typically drive from Liege in Belgium to Bedford England in a single go (pre Chunnel, had to use a ferry/hovercraft) and usually managed the one way on a single tank.  Then I would drive the car all week, fill up using my massive jerry can - we (RAF at the time) got BP coupons for gas at ridiculously reduced prices so anytime we went on a long trip we took along at least one plastic jerry can which held the equivalent of 7.5 US gallons.

For longer trips, such as to the ones to the south of France, Switzerland etc, we would take two jerry cans.

Plus the tent/beds etc

Madness.

(sorry about the hijack, mur's name jogged a memory or two of him in my carport in Delta BC fettling his Mini prior to a trip back to Sask.)

Tony, Robster, Not A Specialist:

nothing you have written is correct, and your post has no relevance to this thread. Go back to your little safe space thread and do not spread bad information on real threads.

On a very rare, very very rare occassion,i agree with with what sir Alex said.,  why do people need two gas tanks? on a mini?????...do you race your car? or do you do cross country trip with your 850cc mini? i mean, i won't do 80mph with my mini all day in the interstate, be it 998,1275 or even 1380. im not insane.  
And if you noticed, the mini gas tank has the electrical gauge mechanism in the middle, so it means that if you fill the gas tank all the way to the top, the electrical gauge mechanism will be submerged in gasoline,if the seal is not good, gas will leak, and also, as the float goes up and down, friction,static electricity and spark may occur and the result?---> kaboom!, ...nope, i don't want to take chances. That's why i only put 3 buck worth of gasoline everytme i go out for a ride.

Sir Alex has a point.,it's a bit illogical to have 2 gas tanks on a mini.

I have travelled all over Western Europe by car.

Those speeds are not uncommon, they are even legal in many Western States.

No, but have you ever driven across Europe on the French, Belgian, German, Austrian and Italian Autoroutes & Autobahns which have much higher average speeds ?
Hammering back from Belgium at a sustained 80+ still saw us needing sustenance or a comfort break before fuel - and obviously 'Battleship Rules' dictate that you top off your tank every time you stop.
Even at the higher speeds, it's still ~250-280 miles per tank, or 3-4 hours sat in a little buzzbox.

Ditto on all of the above

i did this on my 77 MINI.  After making the template from the other side, I marked the hole but cut it smaller than needed.  This gives you a little room to correct if the tank has its own personality

I've done two of these installations and what I would add to the other suggestions is to start with an undersized hole saw and using a half round file, work your way out to the proper hole size.  Check and file. Check and file.  I had more trouble locating the damn RH tank mounting kit than I did cutting the hole.  Good point by Alex, but on our trip to Milwaukee from Seattle, my twin tanked car was the reserve 'tanker' for the two LWB cars that I traveled with.  On these extended adventures we try to avoid the interstate systems and stay on two lane back roads.  Less traffic but fewer gas stations.