Too many too young to remember the good old CJ610 that powered the original Lear Jets, Jet Commanders, Jet Stars, Sabre Liners just to name a few.
When ever you heard one of those motors cranking up and the igniters clicking you only stood behind the exhaust once, and only once. 3 foot lick of flame would come out of the back when light off occured. Pretty exciting to say the least, especially for the chap standing behind the engine.
YouTube - Learjet CJ610 Turbojet Engine In Test Cell
About 20 seconds into the start sequence.