WW2 Avro Aircraft Piston? / post war aircraraft piston? American B29 ?

possible WW2 Avro piston ??
here i have up for auction a very nice aircraft piston.
this item has been released recently from a private collection.
the only details i have for this item is what is written on the tag which is as follows
ww2 Avro piston ?
please do contact me if you have any information which would help in identifying the piston
i have measured the piston and it is 6 and a half inches tall by 5 inches across
please check photos before bidding to make your own mind up as to what this may be from
please do ask any questions and of course to point out any detail.
please note this item is quite heavy so will be posting via courier
low start so grab your self a bargain