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    There are 3 alternatives for the frame when fitting a K series engine.

    1. Make your own using a Mini one as a base or starting from scratch.

    This is the most difficult of options, due to the amount of fabrication required. You can retain the Mini suspension and brakes, but will have to get drive shafts made.

    If you want to fit the engine under a standard length round nose, then this is your only option.

    2. Use a K series frame.

    A potentially much easier solution, especially as it is widely used as a frame for the Vtec conversions, and has been fitted many times.

    You will have to modify the frame in order to mount it to a Mini body. The rear lower mounts either need extending back to the leading edge of the floorpan. Or alternatively box sections can be made up to extend the floorpan forward to meet the original frame mounts. The rear upper mountings are most commonly made to bolt, via plates (from the subframe towers) to the damper mounting bolts, effectively clamping the subframe either end of the bulkhead crossmember. Alternatively it is possible to modify the frame to use tower bolts as per the Mini item.

    If all that sounds too much then Watsons will sell you a frame with the mountings already done.

    Using a K series frame will require the use of a Clubman front (with valence mods) or an extended round nose front. It will also increase the track of your car.

    Watsons -

    Engines & Gearbox

    1.4, 1.6, or 1.8 they are the main 3
    As a starting point one of the most important things is to get a MPi (Multipoint injection) model as a base if you are planning on fitting a 1.4 then upgrading in future.
    The 1.4 and 1.6 share the same R65 box, although the 1.6 is stronger. It also has a different selector mechanism to the Metro one, but this can be easily swapped. The 1.8 uses the PG1 box which will fit, but will require modifications to the frame mountings, and different driveshafts. Happily these bits can be sourced from an MGF, as its frame is basically a Metro item.
    The lesser boxes can be used on a 1.8 engine, with the 1.6 box being prefered. If you can, try and source a later R65U box which are uprated so desirable over the normal R65.
    You also have to use the flywheel which matches the ECU you are planning to use, as there are differences between engine sizes/boxes.


    For simplicity use the Rover Mems ECU, either the complete Metro loom or it can be sucessfully wired up to a Mini loom.
    If you have a 1.4 and want to upgrade then the 1.6 & 1.8 can be run on the 1.4 ECU.

    The MEMS can happily handle many of the basic engine mods, but if bigger power gains are desired then an alternative ECU will be required. Most third party ones can be used, with Emerald being the prefered option by many as it is a straight plug and play item with the MEMS wiring.


    If youre using Mini derived suspension then obviously any Mini wheels will do, if however you use the K series Metro stuff then there are limitations.

    Any of the K series Metro wheels will obviously fit, with one proviso. IF you are using the ventilated disk brake setup fromt the later MPi Gti, you will have to use the matching wheels (7 spoke alloys) as other ones will not fit over these brakes. Modifying the other wheels to fit can be done or the addition of spacers, but neither of these is as desirable.

    The K series has a 95.25mm PCD, and a centre bore of 56.6, the alloys are 5.5 inches wide. GTi Mpi 7 spoke alloys have an ET52 offset.

    A few companies do 14" wheels in a suitable metro fitment. They are usually 6 inches wide and it is generally agreed that an offset of ET38 is the best handling for this size. With any wheels though you will need at least Sportspack size arches, and even then they may well stick out a bit (especially in lower than ET52 offsets).

    A few companies will also make wheels up for you to fit, but dont expect it to be cheap.

    In an effort to get different wheels it is possible to get the PCD of your hubs changed to 100mm (most engineering companies will be able to do this), if you are using Watsons rear spacer kit then they have 100mm PCD holes already there.

    Compomotive -
    Motobuild -
    Rimstock -


    Again the suspension choice will have an effect on brakes, and quite obviously Mini based suspension etc. means Mini brakes will do. The popular Metro 4 pot conversion is probably the most cost effective choice here.

    If using a K series frame then there are basically two flavours of brakes to choose from. All K series Metro models apart from the Multi Point Injection GTi model used solid discs, the Mpi GTi used vented. They are the same diameter, 9.4", and in vented form are the same as used on the MGF. These standard brakes will only fit under a 13" wheel and in the case of the vented option, care has to be taken when using Metro wheels. As stated above the MPi 7 spoke wheel was designed to have clearance for the wider vented setup, so other Metro wheels will not fit without some modifications.

    Suspension & Steering

    When using the K series stuff it is worth noting that the GTi models (and possibly GTa) used different steering arms, and bottom ball joints to alter the geometry. This was to make the car better/easier to drive with the large section tyres (185) fitted to these models. They also had a reduced lock steering rack fitted to prevent the tyres rubbing the body (bit like sportspack equipped Minis). As far as I am aware tyre rubbing is not a problem when fitting K series (or Vetc for that matter) into a Mini, but may explain why you have less lock than you were expecting.


    Bit of a how long is a piece of string question this, but if buying a frame and a doner vehicle then you should be able to get a K series Mini on the road for less than £2000.
    If you make your own frame, then less than £1000 is not unreasonable.
    At the other end of the scale, the sky is the limit, but be aware that just because you have spent a fortune on building/getting a car built does not mean you will be able to sell it for that.
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