5.5 gallon petrol tanks

[phil.1380]

Hi all.

So I'm rebuilding my late (as in 1991) Rover Mini Cooper with twin tanks. I have an "old" 5.5 gallon tank to put in the left side to complement the 5.5 gallon Right hand tank, so I stand half a chance of getting a spare wheel into the boot.

Having wrestled the dam things in and figured out where the straps are going to go I notice that the filler neck on the "old" tank sticks out only about half an inch and points more backwards that outwards, if that makes any sense, as opposed to the Right hand tank where the filler sticks out about an inch and an eighth maybe, and the filler points decidedly outwards.

Did the early tanks change at all (as far as anyone knows) and if so when ?? Looks like my OCD senses mean I'll be putting the 7.5 gallon tank back in for now.............

Any thoughts or experience appreciated.

Phil.

[mab01uk]

A standard size 10" or 12" spare wheel does fit in ok with the later 7.5 gall tank and a 5.5 gall rh tank......although boot space is of course reduced.

[phil.1380]

Ahhh yes, you anticipated the other issue without prompting !!

The car is somewhat of a '90's fashion victim and wears 13" wheels as well, hence the desire for a 5.5 gallon tank.

Phil.

[mab01uk]

When I had 13" wheels I used a standard 12" steel spare as a 'spacesaver' spare.....I assume the Sportpack MPi Minis did the same?

[phil.1380]

When I had 13" wheels I used a standard 12" steel spare as a 'spacesaver' spare.....I assume the Sportpack MPi Minis did the same?

I used to do the same and while it will get you home theoretically fitting the 12" wheel on the same axle as a 13" wheel is illegal.

I don't know what the SportPack Mini's did, I assumed they had a full size spare and like me just has the wheel overlap the battery cover a little...........

Phil.

[IAIN]

Rover olny fitted the standard 12" wheel in all MPI's. The standard wheeel and tyre with a sticker on the same as space saver wheels.

Have you still got the original mounting bracket for the 7.5 gal. tank on the boot floor ? I haven't tried to do this but I would have thought the bracket wouldn't let the 5.5 gal tank sit in far enough ?

[phil.1380]

The bracket on the floor has gone, subject to localised rust repair, but the "bump" on the rear seat pan is still there and I wondered if that was stopping the tank from going all the way in. It's only spot welded to the seat pan so could be removed fairly easily.

The seam on the tank seems (sic) to fit in the right place though, just about inline with the boot stay mount.

Phil.

[mab01uk]

When I had 13" wheels I used a standard 12" steel spare as a 'spacesaver' spare.....I assume the Sportpack MPi Minis did the same?

I used to do the same and while it will get you home theoretically fitting the 12" wheel on the same axle as a 13" wheel is illegal.

I don't know what the SportPack Mini's did, I assumed they had a full size spare and like me just has the wheel overlap the battery cover a little...........

Phil.

I have a New MINI on 205/45x17" wheels with a skinny 115/70x15 spacesaver spare wheel factory fitted, as do many other modern cars, so I would doubt a 12" spare in a classic Mini can be illegal......the rolling radius is nearly the same anyway due to the higher profile tyre on the smaller spare rims.

[phil.1380]

I must admit I had thought about that, but I just assumed the "skinny" wheel was the same diameter as the normal rims obviously with a much narrower tyre.

I thought it was a "construction and use" thing about mixing different diameter wheels on the same axle, a bit like mixing radial and cross-ply on the same axle.

Maybe the rules have changed with the advent of skinnys, anyone "in the Trade" know definitively ??

Doesn't solve my 5.5 gallon tank problem though !! I've seen tanks described as "early", which I assume means MK1 with slightly different pressing and the drain tap, and I've seen photos of 5.5 gallon tanks where the filler neck seems to be in a concave depression in the pressing rather than the usual convex shape, but without the tanks side to side I can't compare the angle and length of the filler.

Phil.

[mab01uk]

I guess it is the speed limit rating which allows a skinny spacesaver to be used.....so if you retain a 12" spare put one of those yellow speed warning stickers on it as Rover did with the MPI Sportpacks and you should be ok legally.

I believe the fuel tank filler necks were changed at some point in the 1980's or 90's to make them shorter lower profile and less vunerable to shearing off, spilling fuel in an accident particularly a rollover.....there is a video on YouTube of a safety expert in a tv documentary pointing out the drawbacks of the early Issigonis Mk1 Mini design for safety and one of them is the vunerability of the exposed filler neck sticking out with no flexible hose connection like most other cars....it goes on to say most concerns were addressed in the later models but not sure that about that......however some easy fixes were like the tilting seats with no safety catch, etc.