Wasn't the DC6B one of the more reliable piston airliners? At least the P&W R2800's gave a lot less trouble compared to the Wright turbo-compound engines on DC7's and Super Connies.
Even so, I remember one of my earliest flights, in the back of a KLM DC6B, Amsterdam to Khartoum. We had an engine failure en-route, and I can still remember the oil flowing back over the engine cowling and wing. This required a lengthy wait at Frankfurt while a new engine was fitted, and off we went again.
My father reckoned he could read a book at night with the glare from the exhaust stacks of the no.3 motor. The inner motors were certainly close to the fuselage. Not as spectacular as the torching from a Wright turbo-compound though, when the fire could sheet back over the wing on take-off and initial climb. The KLM information booklet in the back of the seat cautioned pax not to be alarmed by flaming engines at night, as it was "perfectly normal". I can't imagine pax these days being so easily reassured!
I remember being told a story by a chap who had just arrived in East Africa from London on a South African DC7B. One of the engines had a prop overspeed and then threw the prop as they were crossing the Alps! Luckily the prop trajectory spun it away from the fuselage and no-one was hurt.