Is the block sleeved? I thought it just has a stock bore of 81mm as oppposed to 82 or 82.5mm on the 2.8. Just to leave a little more meat on the cylinder walls. Why would a cast iron block be sleeved?

 

Only real reason for an OEM to sleeve it vs cast it with smaller bores is that all 2.7 and 2.8 engines would start with identical blocks, meaning one assembly line and the manufacturing expense of one block rather than two different ones. Make one block and then sleeve it or leave it as-is depending on its application and it costs a lot less than making two different blocks.

 

So the 2.7 has an original displacement of 2.8 and then sleeved?

 

I don't know if that is what/how they do it - only saying that it would make sense financially for Audi to do it that way. The more parts shared, the higher the profit.