dr_nishu

3-cylinder vs 4-cylinder engines ?

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see nishu, engine efficiency is a matter combinational study of various aspects such torque, power delivery, mileage etc. you can't judge an engine's efficiency just on one parameter. if you are judging it on mileage basis thn its not quite right, because by that way M800 engine would have been much efficient thn BMW or ferrari, which is very rubbish to even hear.

As sm1 wrote about accord's v6 engine, that uses 3 cylinder for cruising. Here point to be noted is that, it uses just 3 cylinders only in while cruising (which requires most least power output from engine after idling). but in other cases it will use all of the 6 to do the job.

Now efficiency of engine depends upon the one's requirement of power and torque. there is no doubt that these 3 cylinder engine works wonder when i talk about 800 or alto where power requirement is not the prime motive. these engines provides very nice lower level power output with impressive mileage.

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Maruti could have made the 1200 cc K series engine with 3 - cylinders also. then it would have been a 3-cyl. 1200 cc engine with lesser friction, lesser moving parts, low on maintenance......

why do they put on the 4th cylinder ??

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my dear friend that way, a 2 cylinder engine would have worked great for 1.2 KB!!!

u r really talking funny, a 3 cylinder engine has its limitations and for providing that middle and higher range of torque and power, engineers had to put in another cylinder for linear power output

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Maruti could have made the 1200 cc K series engine with 3 - cylinders also.

 

Now maruti made 3 potted 1L & 4 potted 1.2L because these both could provide good volumes, as both shares many components,

 

If maruti made a 3 potted 1.2L, then its corresponding  4 potter will be a 1.6L engine, which won't be able to give good volume (costlier & less FE), so this made maruti brought a 1L 3-potter & a 1.2L 4-potter
creativebala2009-10-25 08:58:29

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@bala: who said to you tht 1.6 would not give u a good volume (power and FE)

It won't pass excise benefit and have you heard of any 1.6L car selling 3k-4k per month in India, it had never.

 

India is a VFM market,  where price has to be less and FE should be high. Every other things coms next. So 1.6L as a mass seller, now in India atleast now.

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A 3 cylinder engine is almost impossible to balance completely.As a result a 3 cylinder engine will produce more vibration and noise compared to 4 cylinder one( As per my knowledge in balancing of masses in theory of machines). that's why 3 cylinder accent crdi has more noise and vibration  than 4 cylinder elantra crdi.  Engine power and efficiency are independent of no of cylinder

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I think everybody at here must have heard that A-Star is declared as,'Winner of light car division at Global Green Challenge for emitting just 89.9g.km of CO2 & being rated as 4th most environment friendly car in the world (after prius hybrid, civic hybrid, IQ) by VCD.'

Does this have any relation with its Engine capacity,design & its 3-cylinder configuration ???

Smart answers are welcomed......

(Moderators note please ! Here i'm not merging the other thread but just given/used its reference here to clear this thread's topic.

Waiting for your answers too........)

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Hello folks

Today we see many 3 cylinder engine cars (hatchbacks) at a very premium price. As i am not an automobile engg. I have a query that doesnt 3 cylinder car should cost less than a 4 cylinder car or it depends on some other factors or is it wise to pay a premuim price for 3 cylinder cars?

Thanks

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Yes. But a 3-potter will need an additional anti-vibration component. Also, removing one pot does not reduce the engine cost by 25%. What is happening is that the same engine is being made in 4-pots and to reduce the capacity they remove one cylinder. Remember the old WagonR and Estilo engines were an additional cylinder on the M800 block.

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Besides cylinder there are few other things to pay.
One prominent is a double cam shaft i.e. separate cam shafts for inlet & outlet valves.
Distributer less ignition system.
New improved gear box.

 

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There's a whole world difference between 3 & 4-cylinder engines with their Own Advantages & Disadvantages;

Advantages being:

-Smaller sized construction, ideal for car with Smaller engine bays.

-Having less Frictional losses(about 20-25%, as Nissan claims for their Micra's 1.2l, 3-cyl engine)

-Less Thermal losses(about 10%, again as Nissan claims)

-Better Reliability factor(Remember M800 based 800cc F8D engine is one of the most successful Smallest engine in the History & is from more last 27 years in India).

 

Disadvantages(these are variable & varies from Manufacturer designs & engineering deployed);

-Noisy & Vibrating Idle(now eradicated in Maruti's K-series 1.0l engine).

-High NVH at Powerband Rpm range(eradicated by VW in their 1.2l Polo engines of India).

 

@mods: There was already a hugely discussed thread on this 3 vs 4-cylinder engines, I'm unable to re-locate, as maybe it was bashed during Server breakdown or please Re-locate it.
dr_nishu2010-08-29 15:25:20

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Since it is an old tread being revived let me put some things in perspective at a single place:

1. A 3-cyl engine inherently is disbalanced, so has more vibration. However, in modern designs the balancer shaft etc. take care of this. To get real smoothness you need five or more cylinders since then the power strokes start overlapping.

2. You may have 2, 3, 4 or 5 valves per cylinder. Valves are added to improve the breathing, and more valves lead to increase in power, as well as a wider power band.

3. You have have SOHC or DOHC depending on the design. DOHC will normally rev. higher due to the lighter weight, and though costlier gives the manufacturer more flexibility in the valve design. However, remember the Civic has an SOHC engine and the redline is 6700prm.

3. The M800 was an excellent engine for its age (the same block was used in the Matiz in a 3V/cyl configuration. However, one must accept that the block did normally need to be rebored in 125,000km or so. Many other blocks easily went for 200,000 plus. Also, its 4-cyl version as in the WagonR and Estilo never felt as smooth and responsive as the old 1,000cc block of the Zen.

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However' date=' one must accept that the block did normally need to be rebored in 125,000km or so. [/quote']

 

Does 3-cylinder Engine vibrations or Coarse nature have affect on its Longeivity or Engine's Life ??

As most of the Good 4-cylinder engines normally cross 2-3 lakh kms with Ease.

Please explain this completely sir..

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Hello everybody, this is my first post in any form on the ACI Site.

 Recently I heard about the Fiat Twin air engines and thout that we may now add even 2-cylinder Engines to this debate. Fiat is launching fiat 500 with a 2-cylinder twinair engine which they claim is far better than a 1.4l 4-cylinder engine in terms of power, performance, economy and emission. As prof, SGIITK explained that we need 5 or more cylinder for smooth power delivery since then power cycles can overlap. Here Fiat is claiming that even in terms of smoothness this engine will at least equal to a 4-cylinder engine.

 

So I think as the technology is advancing, in future we are going to more smaller and smaller engines with higher performance and then restriction of 1200cc for petrol engines for small cars in India will be well justified.

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lets be responsible to our mother nature. we all know what was size of the computer when they were launched 6 decades back . Now we all know the peneration of laptops in our daily lives. Future belongs to lighter, smaller, highly efficient engines. I will not be amazed to drive a single cylinder engine car after 2 decades.smiley17.gif

 

why cann't industry ban engine over 1500cc whats the advantage of high capacity engine- High risk of death, gas guzzler, high carbon footprint, eating non-renewable resources of environment and high intial cost, higher maintenance, wastage of precious man hours during manufacturing as well as after sales. ( just think 0-100 in X secs to save few seconds we are killing our future years to come.... just think...smiley19.gif)

 

For that matter in fact I have increased usage of public transport & walking.smiley4.gif We all can make little effort in saving our planet.

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Yes, Public transport is the best option. But, where will all the car manufectures will go. Further, sufficient power is required for a comfortable drive, not for 0-100 sprints or overspeeding on highways.

You require power to quicky reach the speed limit in city, otherwise the person behind you will not let you stay in right lane and keep honking.

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dear friend , engine size will always depend upon the power a particular company wants it to produce , u can't extract 400 hp from a 1.2 ltr engine and be fuel efficient at the same point of time . A V10 will be more fuel efficient than a 400hp 1.2 ltr.

 

Now you might ask whats the need of so much power ? well sometimes it Mass , imagine a 2.5 ton suv with a 1.2 litre engine , it will do 1 ltr for 500 meters. More powerfull does not always meet less fuel efficient.

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Im sorry, I disagree with your view here tushar. I agree about how we should reduce pollution etc, but that doesnt mean you can stop manufacturers from making high displacement engines. If people have the means to buy it, why stop them?? Makes no business sense now does it? If I had the money, I would have certainly bought a big manly Supercharged V8 gas guzzling beast!

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If I go with the same logic why so called 'Virus' companies ( making cigarettes) are being discouraged Now HongKong is no smoking zone even our Shimla is in no smoking zone category . One can argue my lungs my money why Govt. is bothered if i die because of Cancer.smiley11.gif

 

"We Human being must respect the society we live in, this is our responsibilty to change things which aren't benefiting society at large"

 

 

Im sorry' date=' I disagree with your view here tushar. Makes no business sense now does it? If I had the money, I would have certainly bought a big manly Supercharged V8 gas guzzling beast! [/quote']

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If I go with the same logic why so called 'Virus' companies ( making cigarettes) are being discouraged Now HongKong is no smoking zone even our Shimla is in no smoking zone category . One can argue my lungs my money why Govt. is bothered if i die because of Cancer.smiley11.gif

 

"We Human being must respect the society we live in' date=' this is our responsibilty to change things which aren't benefiting society at large"

 

 

']

@tushar i agree m8 , but your tought that the smaller the better doesn't make sense , with heavier and big cars we need more torque and BHP , extract that from small engine and they are as good as an V6.

 

My 3 series gives me 9-10 kmph in mumbai b2b condition (automatic) and my friends i20 1.2 gives around 8.5 kmph .

 

with latest technologies and innovations big engines can be made fuel efficient also. Add hybrid to that and they pit a small 1.2.

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