Twelve years ago, Jack Evans (founder and namesake of Evans Cooling) went to court with the claim that General Motors stole his design for a reverse-flow cooling system, a setup that was later put into production in GM's LT1 series of small-block V8s - and a design that was protected by Evan's patents. Such a cooling system sends cold water from the radiator directly to the heads and then to the block, which is opposite of a conventional arrangement. While it potentially offers a increase in cooling performance, some ingenuity is required to prevent the formation of steam bubbles, especially around the cylinder walls. Evans had designed a restricted vent to evacuate vapor and steam bubbles from the system, and states that GM stole his intellectual property during a test in 1989.
Lengthy litigation followed, with GM winning a 2003 case in Connecticut despite admitting that one of its engineers had falsified engineering documentation in an attempt to demonstrate that the technology had been developed in-house. Another trial is now scheduled to begin later this year, and it is said that GM may be on the hook for up to $12 billion in damages. More so, Evans believes that GM's GenIII small-block also uses his technology, even though that engine has conventional cooling flow.
More information on the case (albeit with an obvious bias towards the plaintiff's view_, can be found at a website Evans has set up to explain his side of the story.
[Sources: Fortune Small Business via Yahoo!]