Why does a V8 have a distinctive "growl" that is a lot different than other engines?
(2011-02-02 15:25:03) 1. Says: Typically, 90 degree V8 engines will use a 2 throw crankshaft, which makes the firing order to favor one side and then the other during a whole cycle.The cylinder firing order would be something like
Left1 - Right 1 - Left 4 - Left 2 - Right 2 - Left 3 - Right 3 - Right 4
The net effect is that there is going to be a alternating 'pulse' in the exhaust piping, shifting from the left to the right manifold, not unlike the V twin of motorcycles that have to go "put-put---put-put---put-put".
V6 will have to use triple throw shaft (and thus a more even firing sequence -- balanced left-right; but not front to back). V10 and V12 will also use crankshaft that have more than 2 throws, and thus can afford a firing sequence that results in a lessening effect of the pulse in the exhaust piping.
Hence, that unique V8 growl.2. Says: . It takes 2 (720 degrees) engine revolutions to complete a 4 stroke cycle which includes 1 "firing" or power stroke. If thats the case then in 1 revolution on a 8 cylinder engine only 4 cylinders "fire". The more cylinders the closer they have to fire together because all engines only rotate 360 degrees. In other words, the more cylinders, the less time there is between the cylinders firing. A v12 has to fire 12 cylinders in 720 degrees same as a 4 cyl has to fire 4 cylinders 720 degrees. They sound different due to the amount of time in between the cylinders firing, thats what give the 10s and 12s their distinctive sounds, the cylinders have to fire so close together to get it all completed in the 2 revolutions.3. Says: Its not "a" V8 engine that has that growl. There's several V8's that sound positively sedate. I'm assuming you're talking about the typical "American V8".
Its not necessarily the number of cylinders - its the dimensions of those cylinders and the general engine architecture. Most have a relatively large bore size relative to the stroke. On top of that, most of the cams are designed to make best power/torque in the 1500-6000 rpm powerband. The firing order of the cylinders also plays a factor, since the exhaust pulses "overlap" from bank-to-bank in a certain sequence at a certain rate.
The combination of all these factors contribute to the characteristics - and the exhaust plumbing does the rest.
The V10/V12 engines generally have much smaller bores - and a much tighter exhaust pulse overlap - making them not necessarily whiny, but more of a constant exhaust tone.
Listen to a Viper's engine - I wouldn't exactly consider that whiny! This is because the cylinder size is closer to a typical V8's, and the only reason it sounds slightly more "sedate" or smooth is because the pulses per rpm tend to smooth the exhaust note. But it still has growl.4. Says: More cylinders. Driving at 2,000 rpm a 4 cylinder fires 4,000 times while a V8 fires 8,000 times. The firing makes the growl or exhaust noise so the firing coming closer together & more frequent make the deeper noise.5. Says: it all depends on what motor it is. different motors make different sounds. not all v8's sounds alike. and v10's and 12's usually have a silencer on the exhaust6. Says: its not so much the "growl" which is from the amount of power..(trust me you can hear power).. but the fact that a V8 is the **** and you can get more power easier than other engines.7. Says: v10's and v12s have a smaller gap in exhaust pulses then a v8 or a 4 cyl Tag: Why does a V8 have a distinctive "growl" that is a lot different than other engines?