Hello,

I’ve purchased an 1100s Manual that has been sitting in a paddock for the past 16 years.

I brought it for the motor with the vision of using it for a mini restoration project for my son and I.

I’m just looking for advice on what’s needed when converting them over to a mini and what I should take out of the Morris 1100S before moving it on?

Thanks in advance for you advice.

Just take the engine and associated parts, carb, starter etc. It will sit nicely on a mini gearbox. I recommend using a mini flywheel too but keep the 1100S backplate.

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The bitterness of poor quality (or Crappy Workmanship) remains LONG AFTER the Sweet Taste of Low Price is forgotten.

Hey TK, out of interest, why do you recommend using the 1100S backplate?

Not questioning the advice just interested to know more.

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

I remember helping out one the tradesman I worked with as an apprentice. He purchased a brand new 1100S short motor to put on his Mini Deluxe gearbox which had S ratios. We had to grind the gear case back to accommodate the 1100S crankshaft

I had an 1100S in my 850.
From memory the 1100S gearbox has a 4.1:1 diff ratio (or there about) so it was very revvy when driving on the highway.
I changed it to a 2.95:1 ind it became an awesome freeway cruiser but a bit slower in acceleration.
I’d recommend a 3.1:1 diff as the acceleration would still be excellent and a great cruise on the freeway.

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Find a job you love and you will never have to go to work !

The deluxe gearbox is only suited to small bore. You need to grind them to clear the 1275 crank.

I believe the 1100s came with the same backing plate as a cooper s but their flywheel was VERY heavy. I reckon that is why TK suggested that.

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1963 Morris 850 Smoke Grey
1963 Morris 850 Shadow Blue
1965 Morris Mini Smooth Van
1966 Morris Mini Van
1969 Morris Mini Deluxe Resto
5/72 Clubman Gt

You could keep the 1100S flywheel but machine the heavy outer ring off it front and back. It's then the same weight as a Mini one.
I'd then lighten it more whilst it's in the lathe.
Would need balancing when done. Cast iron isn't homogeneous like steel.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

You will also need to modify the timing cover plate or swap it for a mini one or cut off the front part where the Morrie engine mount goes. You'll also find the gear shift id different to a mini one as the M1100 one has a rubber sandwich plate between the shifter and the gearbox, you can use that set up but you'll have to move the rear mount backwards in the exhaust tunnel. If using the m1100 g/box I'd change the crown wheel and pinion to a more sedate 3.44 so it's not pulling 6k at 100kph on the 4.26 / 4.11.

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120bhp with 450kg just fun waiting to happen

We were prob. drunk when we set it up last and thought this will be a good idea

"Hey TK, out of interest, why do you recommend using the 1100S backplate?"
because it should be the 22G270. Better material

_________________
The bitterness of poor quality (or Crappy Workmanship) remains LONG AFTER the Sweet Taste of Low Price is forgotten.

Cheers

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_________________
Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

22G270 back plate is NLA but I have a NOS if you need it.

I have 1100S motor in my 1360 van along with the 1100S 3 synchro gearbox. I changed the diff to 3.44 and fitted a Mk1 Cooper S input and laygear. But I kept the original 1100S diff housing with the sandwich plate so I had to fit the remote gear change housing from the 1100S. Interestingly, just to see if it would fit, I did try the 1100S motor on top of my Mk1 3 synchro 333 Cooper S gearbox but the 1275 crank fouled the side of the box.

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Slide
1965 Mini Van (1360)
1970 Mk2 Cooper S (1310)
1978 Rover SD1 V8 (4.6)
1996 Land Rover Discovery V8 (4.0)

Get rid of the sandwich plate and fit a Mini remote type diff housing and extension housing, otherwise there is a mod of welding the two sections of the sandwich plate to make it solid.
I saw a photo on here some time ago.