If this doesn't belong in Advanced Tech, I understand, however I'd really like to know as no matter what the circumstances, I can always tell it's a mustang because of the sound (even when I cannot see them)

The things that I would think affect the sound (tone, Timbre, etc...) are:
1. Material of the block. I seem to remember that cast iron produces a higher "quality" sound than aluminum. I have also heard that one has a higher noise reduction as well. This was a couple of years ago in a materials science class, so I don't remember the exacts though.

2. Process in which the block was produced. I seem to remember that forged pieces also have a much higher "quality" of sound than cast iron. If I am not mistaken it is because the forged piece has a higher density, and that sound travels through higher densities better. I also seem to remember that the casting process produces a grain pattern that had tiny "needles" composed in it. I remember them saying, that is one of the reasons why cast pieces often are very brittle. I believed that anealing improved the grain structure, however I don't think block's are anealed, so I don't think that is a contributing factor.

3. Head design. The small block ford doesn't have siamesed ports, whereas the LT1 does. All that I can tell is that it would seem to me that that would not affect sound, however it would affect a heating effect. I don't know very much about flow rates, but could that be a possibility? I don't think it's 4 versus 2 valves because both the 4.6 and the 5.0L engines have the same sound.

4. Firing order. If the firing orders are different, then the combustion/scavagering process would be affected a lot. Assuming a stock exhaust manifold, both the Ford and the GM have a 4 into 1 design. Because of that, would any firing order issues become pointless, since the entire side dumps into a common collector?

5. Cam. I really don't know a lot about cams, but one thing that I keep hearing is that a tight LSA will result in more of a lopey cam. I certainly can tell the lopiness difference with my Hotcam and a stock cam. I don't understand if or how duration, degreeing, and lift would make any sound differences, but I'm sure they are all contributing factors. To keep the playing field as close as possible, how different is the 5.0L cam from the LT1 cam?

6. Y-Pipe versus seperated dual exhausts (or y-pipe, x-pipe, etc...) With the Y-pipe all the exhaust pulses combind right away, whereas the 5.0L (stock) never combind, or if there is an h or x pipe, they still only partially combind, since they obviously seperate after the 'x' or the 'H'

7. Flow capacity. It would seem to me that the mustang has a much higher flowing exhaust system. If I remember correctly stock is a dual 2.25" or a dual 2.5" Wheras the LT1 has a single 2.75 (Correct?) I realize that a single 2.75" flows more than half of the dual 2.5" or dual 2.25" but it is still probably not more than 60% right? I know that with car audio you can tune a port by it's length and diameter. I also know that a larger diameter pipe will also provide a more hollow sound, however it almost sounds like the mustang is more "hollow" than the LT1. Maybe the true-dual comes in to play here?

8. Dual Cats/Mufflers. Basically the same as above.

9. Muffler type. Again, assumptions here, but aren't both the camaro and the mustang stock mufflers a chamber/fiberglas pack design? I know the mustangs are a true straight through design (in the sense that they are not a crossflow like the LT1's) again, this might also be a combustion pulse thing. Almost seems like the LT1's combustion pulses are merged, then divided in the muffler, wheras the mustang they are mixed (if there is an h-pipe or x-pipe) and then never divide or merge afterwards. Maybe that contributes to a more pure pulse-type sound (aka. in slow motion Boom Boom Boom) instead of a merged, miced Booomoooomooom. I know I'm not very technical here, just trying to figure it out.

I don't really think that stuff like intake and spark plugs would contribute, but maybe they do? The LT1 has longer individual runners, correct?

Thanks for listening to me ramble, just curious and trying to learn how the exact sound is produced

 

V8 2-plane crank engine sound comes almost exclusively from exhaust system configuration. Sure, cam timing changes the idle lope, but the other things like block material, etc. have almost no effect if you can hear any exhaust sound at all. If you've ever compared a "180 degree" header system sound to the conventional sound, or even X style crossovers to no crossover or 2-into-1 systems on the same engine you'll hear the difference.

Intake plumbing/silencing can also play a part, of course if you can hear it above the exhaust.

I always thought the 'Stangs sounded different because they were slightly (or greatly) behind me when their engines were working hard.

 

Hee hee.... "Stang behind me when they're working hard".
That's ballsy considering how many fast stangs there are out there. You get a peanut.

Yeah, the different exhaust setups seem to play a big part in it but even if you dual-exhaust and x-pipe your 350 chevy, it aint gonna sound like a 302 with the same setup.
I've heard some comments on the firing order..... "more bank to bank = higher pitch" and similar which may have some merit. Comparing the LT1 vs LS1 sound difference that is.
On the other side, the firing order (1-8-4-3-6-5-7-2) is pretty well used in everything (CW/CCW) except Ford stuff. Even a RB mopar uses the order, but mopars don't sound like chevies. The hemi is even crazier...... a high-pitched peekity, peekity, peekity, sound (gotta love it). So I'm guessing there's a bit more to it although the hemi has it's own uniqueness.
Maybe the exhaust port shape? Interesting question though.

-Mindgame

 

I would say it has alot to do with cylinder head design.

But this doesn't explain why 4.6's sound almost exactly the same as 5.0's .... good topic BTW.

 

That reinforces that it ain't the engine, it's the exhaust.


Listen to Winston Cup engines. The different sounds of say just the Chevys comes from exhaust. Especially listen to the 4 car, and maybe the 40 Dodge compared to others. When you see some of them upside down Sunday during the "big one" check out the different exhaust configurations.

 

Well, with the fast 'Stangs, it's the blower I hear. Just picked up a Ford mag Muscle Mustangs and Fast Fords, (which might be a double oxymoron), and noticed many of the engine ads are for blowers. Hmmm.

No offense intended; some of my best friends drive Mustangs, but I wouldn't want my daughter to marry one....oops, that's just what she's going to do! Bret's bro-in-law will be a Ford guy. The family will never be the same.

 

Then why doesn't a small block chevy sound like a small block ford with the same exhaust "cofiguration"???

-Mindgame

 

Ah, a Furd in a chevy family.

Not necessarily a sign of dysfunction-in-the-making but yeah... a little troubling.

-Mindgame

 

If I use a Ford rearend in my car, will my LT1 sound different?

 

There are a couple of these I don't understand......

Aren't the Ford 5.0 factory blocks and the SBC 5.0/5.7 blocks all cast iron? Yes, I'm aware the LS1 is aluminum, and I have no idea what the new Ford modular blocks are made from.

Are you suggesting that not all cast iron blocks are castings? That some Fords are "forged"?????

 

As for forged, maybe he meant internals, they had gotten forged pistons for some time.

For the blocks, they have had aluminum blocks, its only recently that the Cobra switched to an iron block due to the blower. I had a 97 and it definately had that Ford sound, even though being DOHC and 4.6L.

 

what about the set up of the air filter, cause i know if theres no filter it changes the sound cause you can hear the engine tone escaping from the heads, i know on the much louder cars you might now hear it, but i guess that a thiner paper filter on a carburator might sound just little different then a k&n on a throttle body

due you think that paper gaskets on the stock manifold would make a difference either?

 

this is definately a topic of interest in my opinion. soundquality is of extreme importance here among the HR crowd.

1. anyone consider the CFM factor? the ford 302 and the 4.6L modulars are mooving far less air than the conventinal SBC.

2. chamber design has a million and one things to do with the sound of a motor a friend of mine here in town has an AFR headed 302 w/ a carb and that things sounds wicked and a half. another factor for a unique combustion chamber and exhaust runner teamed w/ a carb. (also adds brownie points ;D )

3. also, IMO, 9:1 motors sound deeper and more hollow than 10:1 motors, which are much racier ;D most mustangs are around 9:2, so there's another factor right there.

4. firing order was also mentioned by Mr Mindgame. i would imagine that this has somewhat to do with sound as once again, these LS1's sound like nothing else i've ever heard, and sport a non conventional firing order.

since this is mostly speculative, it's pretty much up in the air as to exactly why some cars sound the way they do but as Brett allready mentioned, it dosent matter much when the noise is emulating from behind you. ;D

 

lol... Jim...

~V

 

Yeah, regarding block material, I was referring to Cast for 302, 305, and 350 engines. As some have said though the 4.6L motors were aluminum until Ford put a blower on them.

Good call on the forging/casting call. Kinda hard to forge a block, I don't know why I put that, but it could be extrapolated to the pistons since I would assume they themselves come into play (by a very minute amount)