The great V8 noise.

[.Mark]

We all know it great but (and this may be a dumb ass question) why do the big yank tanks sound so different?
They have the V8 too but the noise is much deeper. I suppose it could be engine size, make, exhaust or something but someone must know.

[Nano2nd]

i would say

a: because most run carbs
b: they don't have cats
c: they are generaly larger that 5.7ltr

the later cars don't sound as good as the classics IMO

[DustyC]

I dont know for sure but I reckon nano is probably right.

[.Mark]

Yes, I just had to er.....pop out do do some....ermm...research.
I think also the auto box has something to do with it, if you leave it in a high gear and slow right down leaving it in that gear whislt accelerating does make a similar noise (so so slow that the engine labours).

SO I think you are right, a factor of all makes the difference.
I'm not one for modding (I leave that to shnozz) but there is always this nagging though in the back of my mind about a 7.6 litre chevy engine being shoe-horned in there

[SXS]

Larger pyramid form crank... creates a better overtone on the exhuast note. Rover V8's are a smaller block but similar pyramid form crank, so you still get some of the deep warble, but not like the bigger block chevvy's and the like.

[DustyC]

SXS is that true?
Not doubting you, just not heard that before.

(By pyramid do you mean the angle? Is this why boxer engines also sound good?)

[raftom]

One basic diference is between cross-plane (like most V8s) and flat-plane crankshafts (like Ferrari, Lotus and TVRs AJP). A cross-plane design fires 8 times in each 2 turns of the crank while a flat sounds as 2 inline-4 working together.

Check the AutoZine Technical School at http://autozine.kyul.net/technical_school/engine/smooth4.htm

[greenv8s]

The cross-plain crank produces an uneven firing sequence on each bank of cylinders so you get a low frequency pulse at 1x engine speed as well as the normal sound at 4x engine speed. This is why you get the classic V8 burble. Similar effect to the classic 2-pot Harley engine, which is the main reason they sound so sexy.