inherent balance is one thing.

exhaust sound is another thing. The exhaust sound is largely determined by the spacing of the exhaust pulses.

An inline6 has regularly-spaced exhaust pulses, which makes it sound the way it does. A Porsche 911, with its flat-6 (perfectly balanced also), sounds distinctly different from an inline6.

A (typical) V8 will have pairs of exhaust pulses bunched together, which will result in a "burbling" exhaust sound.

When we say an engine is "smooth", we are also referring to the engine sound quality, aside from the lack of vibration.

For me, the appeal of an inline6 comes from the thought that there are no unnecessary internal stresses on the engine internals due to imbalance, and the engine feels and sounds perfectly happy at any RPM. Plus if it's a Benz engine, it can run at redline all day long ...

And since my car has a 5spd manual, I use engine sound as an "aural tachometer". Or I just listen to it because it's music to my ears ...

I'll buy that.

Also, I'm kind of a fan of 'boxster' style horizontally oppossed engines because they have a lower center of gravity allowing for better handling, ala Porsche and Subaru.

I'm sure there are other reasons, but at least partly due to the horizontal arrangment of the cylinders, flat-4 engines are much more balanced than inline-4 cylinder engines, which allows larger displacement w/o the use of counter balance rotating shafts.

Case in point is Subaru's 2.5 liter 4-cylinder engine. This engine is smooth w/o these balance shafts.

Heck, Mitsubishi's 2.4 liter 4-cylinder, the new Honda 2.4 liter engine, and Toyota's 2.2 liter 4-cylinder engine all employ the use of counter rotating balance shafts to achieve the smoothness that Subaru's can do without.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

I don't know why but my M103 engine sounds totally different compared to my M104. The E320 sounds like it packs a V8 in WOT but the 300E makes more of a wooshey screaming sound. Thier both I-6's of approximately the same CID so i have no clue how the note can be so different. Any comments?
Adam

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

I used to have a1979 RX-7. By looking at the engine number, a mechanic told me that it was actually one of the first 500 made. The smoothness of that engine was unbelievable! At 90 mph it had this humming sound that made the hair on your neck stand up!! What a joy to drive that car!! I have yet to sit in a car that so perfectly fit my body. Sold it for tuition money for my last year of school. Money well spent, but someday I'll have another one.

Bobby,
Excuse my ignorance, just trying to improve myself as a human being, or at least a car nut... what's the difference between a flat-6 and an I-6?

Stefano,

A flat-6 is also referred to as a horizontally-opposed 6 or a boxer 6, as you would find in a Porsche 911/Boxster, or the Subaru (those with the 6cylinder engines). It is like a V6 with a 180-degree V angle, with opposing cylinders sharing the same crank on the crankshaft. Its main advantage is its low center of gravity.


Adam,

I believe it's because the M103 is a peakier engine, tuned for high-rpm operation. The M104, with its 4-valve head and different intake manifold design, seems to have more uniform breathing throughout the rev range. Of course, their camshaft profiles may also be different.

Go look at a VW Beetle, then you'll see what a 'flat' engine configuration is.

On the subject of engine sounds, see if you guys can identify the engine configurations in these few cars, they're only 100 - 200Kb each:

http://www.maylane.demon.co.uk/engine/1.mp3
http://www.maylane.demon.co.uk/engine/2.mp3
http://www.maylane.demon.co.uk/engine/3.mp3
http://www.maylane.demon.co.uk/engine/4.wav
http://www.maylane.demon.co.uk/engine/5.mp3
http://www.maylane.demon.co.uk/engine/6.mp3
http://www.maylane.demon.co.uk/engine/7.mp3



if you can only afford to download one, make it Number 7!!

later

Russ

__________________
190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg

Engine 1 is the MP3 of the Ferrari V-6 that I referred to earlier. Sweet sound!!

Engine 3...I'm guessing BMW 3.5 liter I-6. Sounds like a "big" inline six.

Engine 7...Ferrari V-12...has to be.

Engine 2...I'm guessing some sort of Mercedes inline six.

Engine 4...V-8 of some type

-Sam

hill - just a light-hearted joke. no offense meant to the mountain man.

whoever posted that mp3 of the M104 - SWEEET!

__________________
Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

Impressive stuff, Sam, I won't reveal what the cars are for a little while yet.
*Anyone* who's driven a car with Engine 4 will be quick to identify it (I don't believe you've had the pleasure )

One of the other engines may surprise you too...

And I can't believe you didn't get 6!


I posted it, but credit to Alon/Ashman for making it (and please make some more!!)


Come on more guesses on these engines people!!

__________________
190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg

Heh...I never took the time to download six in the first place.

My guess...Porsche 911 flat-six. Maybe an early 90's model, doesn't sound raspy enough to be an older car.


-Sam

Aah smeg it I'm not waiting any longer, I'll put you out of your misery Sam

1 - Ferrari Dino V6
2 - How'd you know? Yes it's a 195x 300SL Gullwings straight Six
3 - Big inline Six, correct, but with a little more pedigree than a BMW - a 1953 Jaguar C-type
4 - Recognizable if you know it - an Audi Straight 5-cylinder
5 - A 1958 Porsche 356 Speedster (Flat 4)
6 - An easy one, 911. A turbo too, probably 993 (Flat 6)
7 - Surprising, but it's actually a V8! I've ridden in one of these and you don't forget the sound, it's unique. It's a Ferrari 355.


later all (and I've plenty more...)

__________________
190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg

Well, you aren't the only one who has a collection of car Mp3 files on his or her computer.

-Sam

please