I like to do a lot (maybe too much!) research on things, and it is frustrating finding lots of questions but fewer answers or clarification. I think it's important to at least give back a bit for the benefit of future users...

I'll try to tread lightly here. This thread is a perfect example of how the board should work. You ask a question and got several answers. Had you taken the can't be done advice and let it go at that we would not know what does work. I notice that was tempered with " I believe " which is what we have to do here. There will always be a different opinion and some people are very serious about being right. Thanks for the follow up, so often that does not happen. Steve (CTR) 

The caps that utilize the internal locking gas cap are larger in physical appearance and for me look a little too robust.  I prefer the smaller looking ones and don't need the locking cap.

Just to close the loop...

No problem with the MiniSpares SP288 Aston style cap on my 1999 MPI Mini. The brass collar pounded right on all of the way it needed to and only slighly compressed the filler neck gasket. The flip up cap screws on to the brass collar and voila.

This flip cap doesn't have any internal screw on cap, the flip-top lid has a gasket which keeps the gas in. It's not locking at all. 

-David

If you have 8mm (as originally stated you will (probably) be fine).  I say probably because there's something fishy about the SP288 catalogue listing.  It shows the price as UKP14.99 along with an alternative that seems identical at UKP79... and a replacement brass collar at UKP12....  something is srewy. Is the UKP14 version a cheap Chinese copy?????

I paid something like the higher price years ago and that item is top quality.  You need to bang the collor on with a (soft faced) BFH.... and need a puller to get it off.  If you have 8mil then teh rubber seal would easilly deform the required extra 2mil.  I found teh cap tightened up against its own internal seal (goes between cap and collar) before using all of teh collar thread.  ...And you could easilly trim a bit of teh filler/body collar away if you did want to snug it down a bit more...

Cheers, Ian

Again, THANKS!

I was looking at SP288 which looks like it doesn't require any internal cap (at least in the MiniSpares photo). Maybe I'll order it and give it a try...

Any idea what sort of "glue" to use? I don't want to go through the hassle of welding it on.

-D 

I think it has to be fully over the neck to be able to fit the actual gas cap under the flip top. Most have a brass ring fitted with set screws to hold the unit, and I don't think you can get away with that ring being flush with the top of the neck.... again, you can't get the cap on under it!

Thanks Jemal.

No fake necks on my car and I was looking for a much easier solution than welding a 3mm neck extension on!

Does the brass ring on those models have to be pushed on all of the way flush with the top of the filler neck? I could get it on most of the way, I think... What about trimming the body gasket down a few mm?

-d 

I don't believe that will work either, unless you can reposition/shim the tank upward to reveal more neck. I don't think any of the Monza style flip-caps will fit the MPI....

Of course it IS possible to remove the tank and weld on a longer neck from an earlier tank.... and I've seen the "fake" neck for a ghost tank on the right with the Monza cap, if you can live with yourself!!!

Other option ive seen - Monza cap that latches /screws onto a Locking Gas cap.

 Looks the part- but underneat is the actual locking gascap - you then use your Key to remove for putting gas in the tank.

Kinda a big clunky setup, but works the part.

//www.minimania.com/part/MSA1145/Classic-Mini--Mini-Cooper-Alloy-Petrol-Fuel-Gas-Cap

The amount of tank neck is pretty much the same on all Mini's so i would loosen the tank strap and see if you can gain the extra neck you need by re positioning the tank.

HI!

Anyone know which fancy Monza or Aston flip-type petrol cover fits a late model MPI car. The standard one (SP227 from this site)  from my last car (1977) won't fit as there isn't enough of the tank neck exposed to lock properly.

It looks like SP288 may work unless the brass ring has to be really far on to the filler neck. I've only got about 8mm or so of filler neck depending on how much i push in the body gasket...

Which one should I buy for this newer car?

Thanks!

 -David