Morris Minor Owners Club

I thought I'd share my engine rebuild on here. This is it a standard 1098cc engine from a 1970 Traveller.
It ran ok, but with wandering timing and also low compression on the back cylinder, It didn't smoke noticeably.

I got the cylinder head off and the tops of the pistons were oily rather than coked up. I managed to get one clean with a rag dipped in degreaser
It has a 3 stamped into the top of the block and the crown of the piston.

Am I right in assuming the car has been rebored to ".030 oversize?

Where's the oil coming from? The engine was quiet and didn't smoke? Down the valve guides?

Am I seeing signs here of a leaking cylinder head gasket? It did overheat a couple of times

The pistons were matched to the bores by size during manufacture, so a piston with a 3 on it will fit a bore with 3 stamped on it. This indicates that your engine is probably standard.
When you have stripped the engine, measure the bores at the top, middle and bottom, you may find that they are worn more in the middle. In which case its definitely time for a re-bore.
I would also check that the crank journals aren't oval.

As above.
If you do have the engine re-bored make sure that the bores are sized/graded to the pistons. The BMC factory had lots of different sized/graded pistons to play with but you will only have the one size/grade.

How come it's so oily? There's hardly any coke on the piston crowns, where's the oil coming from?

Probably pooled and dropped down the push rods when you removed the head