The crays full immersion coolant model hit a big problem - the coanda effect.
This is where layer of fluid near the actual component flows much slower than actual flow - in layers slowing down exponentially as it gets closer to the stationary components.
For air this is not too much of a problem - only a very fine layer of stationary air over compenents that does not affect cooling. But with liquids the effect is both noticable and severely impacts coolant flow over hot surfaces - with some then "next gen" cray chips actually boiling the fluid. As todays chips run much hotter and generate a lot more heat than those Cray chips I can see this being a major problem today...
Crays fix for this was to move from full fluid immersion to immersion in droplets 'injected' using a car fuel injector.
This got everywhere and evaporated taking the heat away from components.
Rumor has it that during devlopment, engineers bought fuel injectors for a wide range of cars and the ones for certain porsche worked best so they bought the entire stock of fuel injectors for this car in the mid-west and used them...
I remember staff at cray giving away Porsche style sunglasses with Cray written on them instead of Porsche and when I enquired why - the above was the tale I was told by sales staff.
Whether true or not is something else - the cray sales staff in those days had a seriously odd sense of humor...