Water Cooling With A Car Radiator
sH4RD writes "Why go out and buy a water cooling system when you can do it with an old car radiator? That's exactly what One of The Twelve figured when he used the radiator from his brother's 1979 Toyota Corolla to cool his system. His Athlon64 3000+ can hit 2.5GHz smoothly now. Check out the original forum post complete with benchmarks."
I hate to sound like an elitist, but this is fairly common practice for water cooled PC's. Except most people tend to use smaller heater cores. That, and tend to buy them new and clean.