Sounds like the Factory Recon Short Motor I was offered 4 years back was a bargain at £1,000?  He still has it in its original Factory Crate, tucked away under his workbench.  It has the genuine S crank fitted. I keep hoping he'll come down on his price as he is no longer into the Mini scene, after years of doing Hill Climbs.  Maybe I should just bite the bullet and buy the DAMNED thing.

Sorry to hear about this. Now you know why as a long time machine shop guy I currently use 5 different shops to build my units. One shop can't be beat on cyl heads, one gets all my crank work, two others blocks depending on small or large bore and a shop for balance work. I have had blocks ruined by people who didn't know and would not listen to me. I have a stack of A+ blocks that will have to be sleeved. My guy leaves a step at the bottom and gets the press right. The process is a pure pain as the boring bar for this size work is all manuel and set up is by feel as much as anything. When I dropped off a 998 for .060 bore recently they mentioned the machine had not been used since I did an 850 a couple of years back. I offered to buy the machine but no luck. 

The whole thing is a shame but sleeving a .020 block was a bad call hope you learned something. Pistons are cheaper than sleeves and a block for sure. I put a 1330 block under the work bench for 20 years till I found a set of .080 pistons it was my first Cooper S block which I ran at std/.020/.040/.060 now in street car at .080.  Steve (CTR)

 

PS what are you going to do with those std pistons now? 

My block was already 20 over and needed to go to 30. However, since I had an original NOS set of BMC Racing 18517/KR standard bore forged pistons, the machinist and I thought it would be best to sleeve the block to standard bore and utilize those pistons.

I didn't know this until afterwards.... When the machinist realized he did not have the equipment to sleeve the small Mini engine, he subcontracted the job to another machinist. The result was a disaster. The subcontracted machinist pounded in a sleeve in #3 cylinder and cracked it through into #4. He also snapped off about 1/3rd of the flange on #3. He then attempted to pin the crack he caused between #'s 3&4, but in the process he goofed again and put the pin in at an angle and it came through the side of #4 bore.

Jemal is correct when he said it's "ugly". But the block has also been severely compromised. I am not accepting it from the machine shop. That's the story.

Not wanting to give too much away, the block WAS sleeved by the shop, but did a rather ugly job of it!  Instead of a bottom seating sleeve, they bored all the way through, then used "pins" to locate at the bottom.  It looked like they missed on centering, so you can see 'threads' from the 'pin' in the bottom of the bore.  The piston skirt goes that low.   In my opinion it should work fine as long as the sleeves are secure.... but it's "ugly"!

I said it would be tough to find a standard S block, and if he did, it would not be cheap!

Yes, inquiring minds would like to know.

I can understand boring too big or out of spec, but it would have to be a total disaster to be un-sleevable.

I first worked at then ran an auto machine shop for 25 years would love to know how they broke your block. Steve (CTR)

Machine shop broke my original AEG 312 block so I am looking for a like replacement.

What is the story here?  Would a 12G1279 block work for you?

In in Ohio.

You did not narrow location down much. Blocks are heavy and hard to move around. A std bore 1275 Cooper S block would be rare. I think I have one good at .020 one at .030 needing to go to .040 and a .040 block with four bolt center cap. Looks like I have buckets full of Cooper S rods. Got a call for a crank yesterday. Not interested in sell a block. Much better reward for a complete unit. Steve (CTR)

I am located in USA. Thank you for letting me know about that engine, but I do not have a need for a complete assembly, just the block with its bearing caps will do. Thanks again.

Where are you located?  //www.ebay.co.uk/itm/Classic-Mini-Cooper-S-1275cc-Engine-gearbox-Complete-/251900595677?pt=LH_DefaultDomain_3&hash=item3aa6720ddd

Looks like they are asking in the $7.500.00 range for their Cooper 'S engine/transmission.

 

I'm interested in buying an AEG 312 Cooper S engine block. Original standard bore preferred, not sleeved.

Thanks,

Eric