My knowledge of the 1100s is that its a sports edition of the 1100 and its has the A series 1275 BMC engine. But what about later Morris cars in particular the Morris 1500, does this car have an A series that will fit into a mini?

Morris 1100 = 1098cc A-series with a 3 syncro/ 4 speed manual gearbox.
Morris 1100S = 1275cc A-series with a 3 syncro/ 4 speed manual gearbox.
Morris 1300 = 1275cc A-series with a 4 speed automatic. (no manual gearbox)
Morris 1500 = 1500cc E-series with a 4 speed manual gearbox (Optional 5 speed)

The Morris 1100 and 1100S also were available with automatic gearboxes.

So what real difference is there in the block and crank between an 1100S and a 1300?
None I presume.

There is no difference between an 1100S Auto and a 1300.

and dont forget the morris 1500 was OHC, someone lets go buy a Nomad read a review on one just the other
night when loking through old motor mags...they said it was an ok thing

pointless post, to many but im sure someone wouild have gained interest..
sometimes i just dont know when to jsut stop....

The 1500 was a smaller version of the 1750 motor in the Marina. There was a story going around a when the cars were new and I was youg that the 1500 went as fast as the 1750 so they made the ports smaller to slow it down. BTW the 1500 was put in the Marina as well. They both made good boat anchors.