There are several engine notes that stick the hairs up on the back of my neck, but the BRM V16 has to be my ultimate engine note.
BRM designed the supercharged 1.5 V16 engine in 1947 and it was used in Formula One until the mid 1950s. The engine produced 600bhp at 12,000 rpm. The engine proved to be unreliable at first but the engine was very powerful for the time. Here is a sound clip of the engine at full chat.