OK what do you think sounds best? Flat fours (air cooled of course 
), inline sixes, rotaries, American/Aussie V8s, euro v12s, V10s, inline fours (God forbid), aero engines, F1, diesel locos?
I like it when a diesel loco goes through central station in Brisbane - ground shaking magnificence! 
V8s on the dyno are pretty amazing too...
stephen
Rolls-Royce Olympus 593
An engine still light years ahead of anything else. The sound of 4 of them at take off power and strapped to the fastest commercial aircraft, breathtaking.
I got some favourites, a few before bed.
1951 they could make 600hp from 1.5ltr engine. Pretty mazing. V16 with RR supercharger. After the start skip to around 2:00 It's a big track, most of the vid is the sound of the car round the far side...
Top fuel Dragsters 20-50m down from the Christmas tree, something which needs to be experienced, the sound goes through your whole body
F1 cars, the tv does not do the sound justice
Harley Davisons with a proper OEM muffler on it, the after market ones just highlight what noisy buckets of sh1t they really are
The mazda 787b, the won lemans in 1991, beating all the big name
brands in there little mazda. 700hp out of a 2.6lt. best sound ever.
Carnt link you's to it but its on the tube.
Any Indian Chief at idle......even more agricultural than a Harley 'cos they are all sidevalve motors !!
Stand behind it and experience the exhaust pulses hitting you - and they are great to ride
You can't beat the sound of a thumping great v8 grumbling away at 2000 rpm
This isn't one of them but it definitely has some musical ability in the rhythm section..
If we were still in the days of communications via smoke signals it would score well there too.
Loving all of them !!!!
How about the Atom V8? nothing exceptional in the sound but everything else is.... 
Pweedas I was going to try to find that one tonight, it's great.
Quite possibly beastiest engine in existence at the moment... 144 litre, 7 x straight 6 radial, 8-10000hp, have a look at the size of the intake bell in the middle.
A bloke from way back used to have a soft top one of these. Made the best noises going through the gears but couldn't keep up with traffic.
Surprised no one has put this up yet.
1100 + hp from a Falcon 4L six cylinder engine.
