making an automatic mini

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

brent marsh - 21 Jan 2004 04:09 GMT

I would like to put a 1300 austin america engine and trans (auto) in
my 1968 mk1 mini (van). I have found the donor car and I can take what
I want for $800.00. I think that is a bit to much.
What can I use off of it to turn my car (standard or aleast it was )?
I do not an engine
1. Do I need to change the front sub frame?
2. Can I use the shifter, is it the same as a mini?

any info will be helpful

Cheers Brent

Reply to this Message

tim_lis - 21 Jan 2004 06:56 GMT

1st question would actualy be..why would you want to? and yes you need to
replace the subframe, and diff ratio, and cut holes in the floor...and much
more besides...but as I said why would you want to Auto Minis are the pits !

> I would like to put a 1300 austin america engine and trans (auto) in
> my 1968 mk1 mini (van). I have found the donor car and I can take what
[quoted text clipped - 7 lines]
>
> Cheers Brent

Reply to this Message

Alexander Boucke - 21 Jan 2004 08:03 GMT

> I would like to put a 1300 austin america engine and trans (auto) in
> my 1968 mk1 mini (van). I have found the donor car and I can take what
[quoted text clipped - 3 lines]
> 1. Do I need to change the front sub frame?
> 2. Can I use the shifter, is it the same as a mini?

You can of course use the engine and auto'box from the Austin America. But
you'll need different driveshafts and - if the auto-mini needs a modified
subframe - the one from the America is very different and cannot be used.

Regards,
Alexander

Reply to this Message

Graham - 21 Jan 2004 14:57 GMT

Brent marsh wrote:

> I would like to put a 1300 austin america engine and trans (auto) in
> my 1968 mk1 mini (van).

I built a 1275 auto Mini Moke some years ago. This would be similar.

> I have found the donor car and I can take what
> I want for $800.00. I think that is a bit to much.
> What can I use off of it to turn my car (standard or aleast it was )?
> I do not an engine

Oh yes you do need an engine...

Manual engines cannot be used with auto gearboxes, nor will auto engines
fit manual gearboxes, due to completely different oil gallery
arrangements in the blocks.

> 1. Do I need to change the front sub frame?

Yes. You need a rubber suspension automatic front subframe which will
fit your body.

A hydro subframe can be converted if you get desparate. Later UK Mini
front subframes have different mounting points, so you need to make sure
your auto subframe will fit your van body.

> 2. Can I use the shifter, is it the same as a mini?

The auto gear selector is on a bowden cable, so you can pretty much
mount it wherever you like. Later auto gearboxes have a park position
and the later selector is obviously different.

> any info will be helpful

In Australia there was only ever one diff ratio in auto boxes. It was
about right for a 998cc 700kg Mini on 10" wheels or a 1098cc or 1275cc
Morris 1100/1300 auto on 12" wheels.

A 1275cc auto mini with 10" wheels (or later 12" low profile tyres which
are roughly the same outside diameter) will be undergeared and will be
quick off the mark, but noisy at motorway speeds.

Needless to say, manual diffs won't fit auto gearboxes.

Minimatic drive shafts are the same length as manuals. The short
driveshaft out of a 1100/1300/Austin America is the same as the long
shaft out of a Mini.

The inboard end of driveshafts differs for different Minis depending on
whether they use rubber cross joints (early cars), hardy spicer uni
joints (Autos and CooperS) or inboard CV joints, ("Pot joint", used in
later cars).

If you decide you want to go ahead, email me for more info.

Reply to this Message

Kelley Mascher - 21 Jan 2004 22:11 GMT

As Graham said you will need the complete engine/transmisson assembly.
You will also want to use the short Austin American drive shaft and
keep the hardy-spicer joint from the other side to use on the short
Mini Cooper S driveshaft you will have to supply. You could probably
use the original driveshafts with the Hardy-Spicer joints but they are
not as heavy duty as the AA/Cooper S units and you only have to buy
the short one.

Use the AA shifter.

The AA subframe is way too big. A Mini automatic subframe is really
hard to find in North America. The conversions I've seen have modified
the original subframe. Just hang the power unit over the engine bay
with the subframe in place, lower the power unit and cut away the bits
that are in the way. The radiator side engine mount will remain the
same. The clutch side engine mount is what you will have to figure
out. Keep the AA engine mounts in case you need them.

It's possible that the Mini automatic subframe would also need some
modification to fit the AA power unit. The Mini automatic used a
smaller filter housing than the AA.

Cheers,

Kelley

>I would like to put a 1300 austin america engine and trans (auto) in
>my 1968 mk1 mini (van). I have found the donor car and I can take what
[quoted text clipped - 7 lines]
>
>Cheers Brent

Reply to this Message

Graham - 23 Jan 2004 03:33 GMT

> As Graham said you will need the complete engine/transmisson assembly.
> The AA subframe is way too big.

It's completely different!

> A Mini automatic subframe is really hard to find in North America.

They're pretty rare in Australia too, and they're all hydro here, so I
had to cnvert a hydro auto subframe to rubber for my Moke.

> The conversions I've seen have modified the original subframe.

I've seen one done this way, It was pretty ugly. They had shortened the
autobox by cutting and welding the radiator end engine mount, shifting
the entire assembly slightly to the left.

> Just hang the power unit over the engine bay with the subframe in place,
> lower the power unit and cut away the bits that are in the way.

There won't be any subframe left....

> The radiator side engine mount will remain the same. The clutch side engine mount
> is what you will have to figure out.

The Auto subframe is wider, with the extra space on the torque converter
side. The front rail of the subframe also "bulges" forward compared to
the straight front rail of a manual subframe. This is to let you get the
valve chest cover off the gearbox with the motor and box in the car.

> Keep the AA engine mounts in case you need them.

You'll need the torque converter end mount which is shared with the
Minimatic. The two mounts off the engine front plate are not used. The
radiator to engine backet should have the holes for a conventional Mini
engine mount.

There are two versions of this mount in Australia:

The cast aluminium one used on Minimatics fouls the harmonic balancer on
a 1275 motor.

The pressed steel version used on 1275 autos in the 1100/1300/America
body was designed to be able to be used in a Mini (but apparently never
used in Minis), so it has the required mounting surface and holes to
take the engine mount, but it will fatigure and break in service if used
as an engine mount without modification. Thirty seconds with a M.I.G.
welder before you assemble it will save hours of anguish at the roadside
and in the workshop several months later. I don't have one any more, but
if you email me photos of yours I'll mark up where it needs welding.

> It's possible that the Mini automatic subframe would also need some
> modification to fit the AA power unit.

I had no problems fitting the 1275 autos from Aussie Morris 1300s into a
Minimatic front subframe, except for repeated fatigue failures of the
radiator end mount as described above. The front engine mounting plate
used in the 1300/America obviously has to be removed from the motor or
trimmed with an angle grinder or similar.

> The Mini automatic used a smaller filter housing than the AA.

I don't remember if the short squat 1300 type filter cleared the
subframe or not, because I found a supply of brand new complete long
thin Minimatic type filter housings and filters for about the same price
as filter elements alone.

Reply to this Message