Re: The buzz of a 3 cylinder - Rob E
Dear all,

As a slightly different technical matter, I'd be interested to hear your thoughts on this:

Why does a 3 cylinder petrol engine emit that distinctive buzzy sound, (as a driver of a Suzuki Swift 1.0 '3 pot' I'm well used to it!).

I emailed HJ direct and he said it was due to 'inherent imbalance'. Knowing how busy he is, I was wondering if any of you could elaborate on this. Why is it that one cylinder less (from 4) produces such a distinctive noise, so different to a 4 pot. With the growing popularity of 3 cylinder engines, (eg VAG 1.2 unit, plethora of them amongst small Japanese cars etc) I'm sure this issue may be of wider interest.

Mnay thanks
Regards,

Rob E
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Re: The buzz of a 3 cylinder - dave18
I don't know the answer. However I remember being a passenger in a hired Matiz. At 90, the noise is great! Those things really roar when thrashed (which they have to be, to extract an inkling of performance.) You would think you were doing far more if you couldn't see the road ahead or the speedo.
A second question: why does a 6 cylinder make a glorious howl when a 4 or even 5 cylinder will just sound gruff at best?
Re: The buzz of a 3 cylinder - MikeC
A second question: why does a 6 cylinder make a glorious
howl


And a third: why do V8's roar like they do? Parents had a Rover 3500S when I was a kid - I'm sure thats where I got my love cars from!
Re: The buzz of a 3 cylinder - J500ANT
If anyone wants to hear a nice 3cylinder motor on song, have a look at these two videos of the new smart Roadster. (Dubious bit of driving in one of them though!)

www.treumann.de/2002/03-roadster-nizza/videos/SMAR...G

www.treumann.de/2002/03-roadster-nizza/videos/SMAR...G

Tony :)
Re: The buzz of a 3 cylinder - glowplug
Well a few rough guesses would be, imbalance - there's no way you can balance it a balancer shaft will just mask the fundamental problem (as per HJs suggestion), different harmonics and for a given RPM more power impulses - a bit like the difference in a 2/4 stroke.

Engine type and setup will make a large difference, boxers sound very different to in lines, etc.

I'm sure a more in depth explaination will be provided.

Steve.
Re: The buzz of a 3 cylinder - Dude - {P}
In my youth (many moons ago), I used to run a 3 cylinder two stroke Auto Union (forerunner to Audi), to which I fitted a straight through copper exhaust pipe, with a fishtail. The noise from this motor was the most glorious rasp, I have ever heard from any car or motor bike, and on a clear frosty night could be heard from at least a mile away. Obviously this was long before M.O.T`s and current noise regulations, and if used today would probably result in a massive fine or vehicle conviscation. !!!
Re: The buzz of a 3 cylinder - PhilW
And talking of old 3 cylinder engines, does anyone remember the noise made by those old Commer trucks which had a 3 cylinder, horizontally opposed, two stroke, (supercharged??) diesels? They used to "scream"! Made the hairs on the back of my neck stand on end!!! Magnificent noise (but without equivalent progress!!!)
Re: The buzz of a 3 cylinder - Dude - {P}
I do indeed recall the engine note of the old Commer diesels, which under full load was absolutely superb. However this engine although it was a 3 cylinder, had 6 pistons horizontally opposed in two banks of 3, which were connected via geared crankshafts.
Re: The buzz of a 3 cylinder - Crinkly Dave
Yes, and with a supercharger.
Re: The buzz of a 3 cylinder - chris p crisps ©
I do indeed recall the engine note of the old Commer
diesels, which under full load was absolutely superb. However this engine
although it was a 3 cylinder, had 6 pistons
horizontally opposed in two banks of 3, which were connected via
geared crankshafts.


They sounded good from the outside but if you had to drive one all day you needed ear defenders.We had a cattle truck / horse box and glad to hear the back of it.
chris
Re: The buzz of a 3 cylinder - Hairyharry

The 6 pistons were connected by a system of rockers to a single crankshaft.
Re: The buzz of a 3 cylinder - simmo
As opposed to some not quite so beautiful 3 cylinder noises, have you ever heard a Laverda Jota on song!!! nothing like it..
Re: The buzz of a 3 cylinder - simmo
As opposed to some not quite so beautiful 3 cylinder noises, have you ever heard a Laverda Jota on song!!! nothing like it..
Re: The buzz of a 3 cylinder - thebouncingbunny
ive not managed to hear the sound of an mcc smart(????stupid more like)yet cos im to busy laughing at the rancid looking thing and the saps in it who think they look cool!seven grand well spent?dont make me larf,emperors new clothes or what!
Re: The buzz of a 3 cylinder - dave18
The Smart is good for what it is designed to do. Fun city car, decent load space, little engine for little speed. It doesn't make avery nice noise - a neighbour back home has one. Strangely, he drives it half a mile to the train station and back each day and no more.
Re: The buzz of a 3 cylinder - J500ANT
Oi Bouncingbunny, wash your mouth out!

Actually, I have a new smart on order, but I NEED an automatic and so where else can I get a new two pedal car with the spec of a smart Passion for £8800 otr (including paddleshifts!)? The residuals are good, the build and design is good and despite what Dave18 says the noise that the new ones make IS rather nice. As everyone has said about 3pot cars, its a funny noise thats rather intoxicating! Listen to the engine note in those videos and you'd have to admit that you'd struggle to get such nice noises in any other car thats from £6.5k NEW! Thats what I think anyway!

Tony
Re: The buzz of a 3 cylinder - jc
I recently drova 1.2 3-cyl. diesel VW;nice car; shame about the engine.
Re: The buzz of a 3 cylinder - thebouncingbunny
nothing personal ant,each to theyre own i suppose but nearly nine grand?there must be lots of small autos out there with the added benefit of 4 seats that wont look like falling over even when stationary!have you specced the"tie die" rancid colour scheme?seriosly tho hope it lives up 2 expectations,have fun,bunny
Re: The buzz of a smart 3 cylinder - J500ANT
thebouncingbunny:

I love it and i only got it at 4pm! My smart is silver tridion frame and red panels with a grey interior. Tonight i have been out driving way too fast around wet roads and not a hint of being introduced to the scenery. I am going to have a problem running it in because the noise the engine makes is addictive.

As for other 4 seat autos for £9k, you try to find one with all the kit that the smart comes with. £10-11k is more realistic, you're paying for 2 seats that rarely get used. (and its an excuse not to be a taxi service!)

Tony
Re: The buzz of a smart 3 cylinder - thebouncingbunny
know what you mean about taxi service,have got an mx5.they soon stop expecting that lift!give it some stick.glad to hear your choice of colour .saw a particularly horrid hearing aid biege one today mmm nice........
 

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