XK 140 Cooling Fans

My XK140 seems to run on the warm side in 100 degree So-Cal days. Thoughts on changing from a 6 blade to an 8 blade fan for better cooling in traffic? Adding an electric pusher fan in conjunction with stock 6 blade fan.I recall seeing a plastic fan blade advertised but can not recall where. Any and all advice is appreciated, the car has a rebuilt engine, and the original recored radiator. Thank you.

Have a look here…towards end of the thread…Steve XK 150 running hot - #10 by ledo

yep…as said see the recent thread, same topic…but for here and now…another yep…your XK140 will run warm on 100 F days…so what is warm? You don’t have to fiddle with the fan much unless for stopped in traffic. At reasonable speeds…30mph and up, it is not your fan anyway…IF your system is in good shape, if you run at least 50 50 antifreeze, if you add some Water Wetter type product as directed, anywhere from 75 to 90C will be normal on a 100F drive. On those hot days, It is kinda like the ol joke tho…Man says to the Dr…Dr it hurts when I do this…Dr. says “Don’t do that”. I know…sometimes driving home from an event puts you in the heat of the day…avoid traffic. See the other thread for more. Nick

Hi Nick,
Couldn’t agree more with you about driving on high temp. days, I don’t venture out in the 150 in our very hot summers. The cabin temperatures in the FHC can become very uncomfortable, an OTS or a DHC may give some relief but the added direct sun’s rays raise alarm bells with me with Australia being the "Melanoma " capital of the world. As you stated the fan does not come into play when on the go as with most modern cars the electric fans only come on when required, and that is how I have set mine up, which suits me and my driving excursions.

Hi Steve,
The reference you gave is for my 150 and the radiator set up for a 140 is different, the 150 radiator being slanted and the 140 being perpendicular which would give very different results having the fan at 90 degrees to the radiator and equidistant to the core

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The 140 radiator is slanted as well.

Do you really have a 6 blade fan in an XK 140? This is a standard fan for the XK 120 and I believe the water pump hub differs for the 6 and 8 blade, meaning your water pump is probably XK 120 as well… I also understand that the XK 120 fan is smaller in diameter than the 8 blade XK 140 meaning less flow.
Or do you have the correct 8 blade fan but want to “upgrade” to the 12 blade XK 150 fan?
Bob K.

Thanks Bob, obviously I have not had anything to do with 140’s!!

The 140 has a slanted radiator and the fan should be 8 blades and 16" across the tips (40.6 cm). The SS, Mark IV, Mark V, late 120, and mid-range Mark VII had at least 3 different fans, all with 6 blades, all of which will fit on a 140 water pump but will of course not give you the air flow of the 8 blade fan.

Any consensus on the 11 blade fans for 140 & 150 offered by Welsh?


The bolt pattern of the 6 blade XK 120 fan/hub is “rectangular” and different from the one of the 8 blade XK 140 fan which is square. Of course you could reposition the holes but it is not a 1:1 exchange.

Bob K.

As you will note in the attached Service Bulletin #169, the 140 had 3 different radiators and 2 different fans. The early 140’s had radiators essentially identical to the XK120. The XK140 slanted/inclined radiators came following limited or substantial production, depending on the model.
Service Bulletin No. 169.pdf|attachment](upload://4v69R3ivpVBoJBlbOIKE6iDrRRo.pdf) (992.5 KB)

Here’s the service Bulletin 169 as a .jpg

I have the stock fan blade, 8 blades. I mis counted. I know one vendor was selling an aftermarket blade, may have been Welsh