my first disgusted spectator

[CobraV8]

Originally Posted by patrickt

[/i] See: Aluminum small block pros/cons?

Interesting theory from an engineering standpoint

So your car is emitting it's exhaust sound off the engine block rather than out of the tailpipe?

Simon

[patrickt]

Originally Posted by CobraV8

So your car is emitting it's exhaust sound off the engine block rather than out of the tailpipe?

Both. Otherwise, a small block aluminum 427CID engine with the same compression ratio, horsepower, and timing events would send out exactly the same vibrations as an iron block FE (which they don't). An aluminum bell, with exactly the same cavity size as a larger iron bell, will sound completely different even when struck with the same hammer using exactly the same force.

[CobraV8]

Originally Posted by patrickt

An aluminum bell, with exactly the same cavity size as a larger iron bell, will sound completely different even when struck with the same hammer using exactly the same force.

That is correct. The natural frequency of an oscillating system is the squareroot of the stiffness divided by the mass, it works this way both for a bell and an engine block.

However if I followed your logic that the mass difference between the blocks makes a difference you can hear I must have given my small block car a deeper exhaust tone by eliminating rubber engine mounts and bolting the engine and transmission directly to the frame. This effectively increases the mass of the oscillating system by a huge amount (engine+transmission before, engine+trans+frame after).

Also what would happen to your car if you installed one of these aluminum toploaders? Would the decreased mass make it sound like a small block

Otherwise, a small block aluminum 427CID engine with the same compression ratio, horsepower, and timing events would send out exactly the same vibrations as an iron block FE

I'd tend to say in that case the aluminum engine block would emit even more sound energy, as cast iron has much better damping capabilities. However compared to the sound coming from the tailpipe the difference in mechanical vibration of the block was absoltely negligible.

(which they don't).

You sure?

[patrickt]

But everybody does not prefer the sound/vibration of a big block. Any more than all people like the sound of high winding smaller CID cars, the F1 cars, or all the variations in between -- Japanese fart cans are the worst, especially when they're faster than your Cobra. On my car, I actually went to additional extremes with the sidepipes to have them built to be "quieter." They are not terribly loud, in volume, as compared to a lot of big block Cobras. But you still feel the sound.

[CobraV8]

Originally Posted by patrickt

But everybody does not prefer the sound/vibration of a big block. Any more than all people like the sound of high winding smaller CID cars, the F1 cars, or all the variations in between -- Japanese fart cans are the worst, especially when they're faster than your Cobra. On my car, I actually went to additional extremes with the sidepipes to have them built to be "quieter." They are not terribly loud, in volume, as compared to a lot of big block Cobras. But you still feel the sound.

Your argumentation here is kind of highly unscientific

However be assured that I like the sound of a big V8 engine

[patrickt]

Originally Posted by CobraV8

Your argumentation here is kind of highly unscientific.

This one was not meant to be scientific. I was out for a drive a couple of years ago with my wife and there was a small block SPF along side of us that, seemingly, was as quiet as a new Toyota. My wife turned to me and said "Why can't your car sound like that?"

Originally Posted by CobraV8

However be assured that I like the sound of a big V8 engine

Uhhh, me too.

[Racer_X]

That's when I'd of come home alone, after kicking her out of the car.

jk,

but " I " would do that. And my wife wouldn't say that.

Originally Posted by patrickt

This one was not meant to be scientific. I was out for a drive a couple of years ago with my wife and there was a small block SPF along side of us that, seemingly, was as quiet as a new Toyota. My wife turned to me and said "Why can't your car sound like that?"



Uhhh, me too.