Cooling assembly is 5FGKT; if the Sanyo Denki fan is sold separately *shrug*, it is MVDCV

Contact Dell Spare Parts, or GoogleFu 5FGKT & MVDCV. That is all the info I have

eBay / US: http://www.ebay.com/itm/FOR-New-original-DELL-alien-Alienware-X51-R2-R3-water-cooling-radiator-fan-syste-/332369097009?hash=item4d62bdf131:g:~RoAAOSwm-pZrY~K 

***I have no info on differences between these air-cooled models / do not own this computer 

Thanks very much, although the eBay item was much more expensive than I was imagining. Are you able to tell me whether the R3 air cooler was the same as the R1, or whether there's another part for that?

Many thanks

G0FC5 : Module,Thermal,Fan,Central Processor Unit,LIQUID,X51R3
5FGKT   ASSEMBLY, HEATSINK, LIQUID COOLING, R3

MVDCV is just the fan and may be hard to find.

SANYO DENKI 9BMB12P2J619  SAN ACE 97 x 33 mm

http://www.sanyo-denki.com/sda/data/cooling/catalog/Blower.pdf 

Thanks very much.

I understand the Liquid Cooling was optional - would anyone please be able to tell me whether the non-LC option was the same as the cooler from the R1? Or what the part number for this might be?

Thanks a lot