>>28462719NTA, but the XKR looks closer since it has the hood vents.
But yeah they even use V8's from the same family.
2011 V8 Vantage uses the ~420HP naturally aspirated AM14 engine, but the AM14 engine is at its heart, a development of the Jaguar AJ-12, specifically the 4.2L AJ-12 Jaguar was using from 2002. Aston took that engine and modified it for their own use, originally as a 4.3L and later in 2009 as a 4.7L.
Jaguar themselves updated to a new AJ-12 for the XK/XJ in 2009, the 5.0L AJ-V8 GEN III which made ~380HP when naturally aspirated, but ~500-540HP when supercharged like in the XKR or XKR-S.
The XKR/XKR-S are really just a cheaper Vantage, both were designed by Ian Callum, both were launched in 2005 for the 2006 model year, and the 2009 facelift for the XK brought it even closer to the Vantage in looks.
Biggest difference was the price. base model XK's were ~$65-70k, base model Vantage V8 was $110k