Single piston vs dual piston engine

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Nihal86 (Nihal86) 2016-07-22 02:08:44 +0500 #1

salam friends.
i tried to search on the web but could not find a reasonable answer.
what i want to ask from experts is that. lets say there are 2 engines both are 200cc. one is single cylinder while other is dual cylinder.which engine will deliver best?fuel consumption of both?
power of both?
thanx.

nihilist 2016-07-22 02:25:17 +0500 #2

If you mean single vs dual CYLINDER, then you may find your answer in this reddit thread:

https://www.reddit.com/r/motorcycles/comments/2fl2c9/eli5_the_pros_and_cons_of_single_vs_double/

Hope that helps.

p.s. searching for single vs dual piston kept throwing up results for dual piston brake calipers, and I'm assuming that's why you were having trouble finding anything online.

k-four-nine 2016-07-23 09:50:00 +0500 #3

You mean Single Cylinder vs. a Twin Cylinder Engine...?

Well, Twins comes in various shapes & forms...

The most common is "Parallel Twin" which is basically two cylinders side by side... Like an inline-4 you may find in a Civic, only half the cylinders...!

And then there're "V-Twins" (Sometimes called "L-Twin") which is basically two cylinder arranged in a "V" Configuration... It's a more expensive design, hence you won't find it in cheap basic motorcycles, not anymore... But this design is slimmer than a Parallel Twin hence the bike can be narrower & more compact... Besides, it doesn't have the "Rocking Couple" problem of the inline twin, hence they can rev much harder than a Parallel Twin Engine...!!! And 90 Degree or near 90 Degree Designs yield perfect primary balance, hence all Ducati's tend to possess 90 Degree Engines...

This is a typical 45 Degree Engine found in cruisers notably Harley Davidson & Choppers with massive 2,000cc S&S Engines:

This is a 90 Degree Engine from a Ducati:

Notice the 90 Degree Angle... Each cylinder basically muffles other cylinder's vibration, hence they're WAY smoother than a Parallel Twin, and as such can rev as much as 12,000RPMs... You won't find a Parallel Twin that revs more than 10,000RPMs...

DO TWINS CONSUME MORE FUEL THAN A SINGLE...?

Short answer: YES!!!...

But at the benefit of less vibration, more (WAY MORE) Horsepower, and most importantly... GREAT SOUND

I know you asked just for the fuel consumption, but I gave you some basic information regarding twins as I thought you might be interested in engines...

Good Day!

Xulfiqar (Xulfiqar) 2016-07-23 12:29:37 +0500 #4

k-four-nine;5147763:

You mean Single Cylinder vs. a Twin Cylinder Engine...?

Well, Twins comes in various shapes & forms...

The most common is "Parallel Twin" which is basically two cylinders side by side... Like an inline-4 you may find in a Civic, only half the cylinders...!

And then there're "V-Twins" (Sometimes called "L-Twin") which is basically two cylinder arranged in a "V" Configuration... It's a more expensive design, hence you won't find it in cheap basic motorcycles, not anymore... But this design is slimmer than a Parallel Twin hence the bike can be narrower & more compact... Besides, it doesn't have the "Rocking Couple" problem of the inline twin, hence they can rev much harder than a Parallel Twin Engine...!!! And 90 Degree or near 90 Degree Designs yield perfect primary balance, hence all Ducati's tend to possess 90 Degree Engines...

This is a typical 45 Degree Engine found in cruisers notably Harley Davidson & Choppers with massive 2,000cc S&S Engines:

This is a 90 Degree Engine from a Ducati:

Notice the 90 Degree Angle... Each cylinder basically muffles other cylinder's vibration, hence they're WAY smoother than a Parallel Twin, and as such can rev as much as 12,000RPMs... You won't find a Parallel Twin that revs more than 10,000RPMs...

DO TWINS CONSUME MORE FUEL THAN A SINGLE...?

Short answer: YES!!!...

But at the benefit of less vibration, more (WAY MORE) Horsepower, and most importantly... GREAT SOUND

I know you asked just for the fuel consumption, but I gave you some basic information regarding twins as I thought you might be interested in engines...

Good Day!

all hail the duke L engine... its :* and sounds lovely at mid to high rev. At idle the ducati dry clutch has the worst sound in the motorcycling world.

Xulfiqar (Xulfiqar) 2016-07-23 12:39:07 +0500 #5

you forgot this one,

BMW boxer twin - torque ki bharmaar

margallar (margallar) 2016-07-23 14:13:48 +0500 #6

wot dafuq, alternator on a bike engine

Hassan1991 (Electrical Engineer ) 2016-07-23 17:42:37 +0500 #7

180' Porsche style....

a4anees (a4anees) 2016-07-24 10:00:04 +0500 #8

Please clear my confusing mind.
If a engine with 1 piston contains 4 valves, by 4 i mean 2 intake & 2 exhaust.
And second engine contains 2 pistons with 2 valves in each piston's top like CD200.
Which egine will generate more power.

Hassan1991 (Electrical Engineer ) 2016-07-24 10:41:11 +0500 #9

Power depends upon displacement and valves diameter where's 1 piston contain 4 valve remain more cool and perform better...

saboor73 (Saaboor A saad) 2016-07-24 11:16:23 +0500 #10

Depends upon lot of thing but if we just take valves in account a engine with 2 valve will prouce good torque on low rpm and will lose all its power on rpm and a 4 valve engine would prpduce less torque on low rev and more hp on high rpm

Hassan1991 (Electrical Engineer ) 2016-07-24 11:24:36 +0500 #11

Don't understand how 2 valves (one for intake and one for exhaust) produces more torque at low rpm???

k-four-nine 2016-07-26 10:01:10 +0500 #12

Well, in a sense; a Boxer is basically a V-Twin with a 180 Degree Angle...! But yes, I did forget about it...!

And I also forget about this:

Longitudinal mounted V-Twin, a signature of Italian Moto Guzzi...

Yes, it does sounds LOVELY... Like a V-Twin, correct?

Most New Parallel Twins sounds lovely...!!! Whereas old Parallel Twin sound pretty dull, right?

Take Yamaha FZ-07 for example, its a Parallel Twin and yet it sounds more like a Ducati...!!! WHY???

Because of the crank firing order...!!!

Thing is, brother... Old Twins (Notably vintage Triumphs, Nortons, & BSA etc) used to have a 360 Degree Crankshafts a.k.a THE BIG-BANG FIRING ORDER... The reason is because in this configuration, BOTH pistons move at the same time...!!! They've virtually identical TDC (Top Dead Centre) & BDC(Bottom Dead Centre) hence these engines sounds more like a SINGLE than a TWIN, couldn't make as much power as a V-Twin and wouldn't rev as hard... On the plus side; both cylinders could be fed by the same carburetor... Our CD200 & CD175 is a good example of this kind of Parallel Twin...

Then Japanese took over this British Design, and gave cylinders a 180 Degree Crankshaft firing order... Which basically means that when the one cylinder is at its TDC, the other is at the bottom of the cylinder or BDC... It created more power than The "Big Bang" Engine because of less vibrations, although this firing order offsets the crank hence it causes a "phenomenon" (LOLz!!!) called "Rocking Couple" so the whole engine shakes side ways and make violent vibrations at high RPMs... Kawasaki Ninja 250R is a prime example of this type of Parallel Twin... And since the pistons don't move together, each cylinder must be fed by separate carburetors... Hence Ninja 250R has TWO Carbs...!

Recently; manufacturers have come with a REVOLUTIONARY design (To me, anyway!)... It's not 360 Degree, neither 180 Degree... It's a 270 Degree...!!!

In a 270? engine, one piston follows three quarters of a rotation behind the other, hence create a RUMBLE like a 90 Degree V-Twin (a.k.a DUCATI!!!)... Hence when you hear an FZ07 (or any other bike with such a firing order like Triumph Scrambler, Honda NC750, CRF1000) with eyes closed, you would swear you're hearing a Ducati Monster or a Suzuki SV650...!!!

This technology made its debut in mid-late 90s and is now pretty popular as most Parallel Twins are coming with 270 Degree Crankshafts now...

Good Day!

k-four-nine 2016-07-26 10:25:25 +0500 #13

There are so many factors to consider... Saying ALL 4 Valve per Cylinder engines makes LESS torque than a 2 Valve per Cylinder Engines would be an overstatement...

Here, take Triumph Thunderbird Commander for example:
2014 Triumph Thunderbird Commander specifications and pictures

DOHC... Check.
8 Valves... Check.
Liquid Cooling... Check.
Fuel Injection... Check.
6 Gears... Check.
Dual Crank Pin... Check.
270 Degree Crank... Check

It's got all the "Stuff" one might find in a Yamaha R1... (Excluding the number of cylinders, of course!)

And yet it makes MONSTROUS torque: "146.00 Nm (14.9 kgf-m or 107.7 ft.lbs) @ 2750 RPM" and redlines at just about 6,000RPMs

Trust me, brother... That's more torque than a Harley Davidson with an OHV 4 Valved 45 Degree Air-Cooled V-Twin with a displacement of 1,640cc and a single crank-pin design (ANCIENT!!!)...

Manufacturers can tune the engine they way they see it fit (And also considering the intended application, of course!)...

Hope it helps...

saboor73 (Saaboor A saad) 2016-07-26 11:39:40 +0500 #14

k-four-nine;5150961:

There are so many factors to consider... Saying ALL 4 Valve per Cylinder engines makes LESS torque than a 2 Valve per Cylinder Engines would be an overstatement...

Here, take Triumph Thunderbird Commander for example:
2014 Triumph Thunderbird Commander specifications and pictures

DOHC... Check.
8 Valves... Check.
Liquid Cooling... Check.
Fuel Injection... Check.
6 Gears... Check.
Dual Crank Pin... Check.
270 Degree Crank... Check

It's got all the "Stuff" one might find in a Yamaha R1... (Excluding the number of cylinders, of course!)

And yet it makes MONSTROUS torque: "146.00 Nm (14.9 kgf-m or 107.7 ft.lbs) @ 2750 RPM" and redlines at just about 6,000RPMs

Trust me, brother... That's more torque than a Harley Davidson with an OHV 4 Valved 45 Degree Air-Cooled V-Twin with a displacement of 1,640cc and a single crank-pin design (ANCIENT!!!)...

Manufacturers can tune the engine they way they see it fit (And also considering the intended application, of course!)...

Hope it helps...

And the reason yamaha r1 have so much torque because of crank design every cylinder is 90 degree apart unloke many engine which are 180 degree a part this makes power stroke closer on down sidw wngine losses all it smoothness

Xulfiqar (Xulfiqar) 2016-07-26 12:57:50 +0500 #15

yes - BMW boxer - it also has a clutch and pressure plate like your car.

Xulfiqar (Xulfiqar) 2016-07-26 13:07:20 +0500 #16

k-four-nine;5150961:

There are so many factors to consider... Saying ALL 4 Valve per Cylinder engines makes LESS torque than a 2 Valve per Cylinder Engines would be an overstatement...

Here, take Triumph Thunderbird Commander for example:
2014 Triumph Thunderbird Commander specifications and pictures

DOHC... Check.
8 Valves... Check.
Liquid Cooling... Check.
Fuel Injection... Check.
6 Gears... Check.
Dual Crank Pin... Check.
270 Degree Crank... Check

It's got all the "Stuff" one might find in a Yamaha R1... (Excluding the number of cylinders, of course!)

And yet it makes MONSTROUS torque: "146.00 Nm (14.9 kgf-m or 107.7 ft.lbs) @ 2750 RPM" and redlines at just about 6,000RPMs

Trust me, brother... That's more torque than a Harley Davidson with an OHV 4 Valved 45 Degree Air-Cooled V-Twin with a displacement of 1,640cc and a single crank-pin design (ANCIENT!!!)...

Manufacturers can tune the engine they way they see it fit (And also considering the intended application, of course!)...

Hope it helps...

Yam also have their odd firing inline 4 with strange looking counter balancers on their new R1 - it gives the bike the initial to midrange punch of a V twin and the peak of an inline 4 all while being able to not spin the rear wheel hopping mad. (<==== traction = win)

But - in personal experience, a BMW twin torques like a turbo diesel (I like that), you ride the wave of torque, if you want to pass you just twist and shoot, in Guzzis - you feel like you are trying to handle a stupid yet powerful horse, its got the punch alright - but the damn throttle is so hard to rotate that your wrist starts to hurt, same with the clutch. But its fun nonetheless for a while just like dukes - I think it has to do with being built in Italy where longer highways are non existant.

btw - the triumph thunderbird is truly a masterpiece - I tested one but didnt buy (because to buy one means I have to choose between family or machine).. The way a thunderbird can go is.... - I have no words, sorry Im not a poet.

yes it is known that engine torque range is not just limited to valving, its about how the bottom end is built, how far apart are the firing angles, the rod/stroke ratio, the borexstroke ratio etc. - all this leads to unique engine operating characteristics - e.g. a chevy LS1 is an oldschool american style offbeat V8 engine - this is an advantage and a curse for it at the same time, its the balance of the two where the buyer looks at which side are the scales tipping for decision of purchase.

offsetting the cranks has been done for quite a while now - and its not just limited to motorcycle engines. e.g. the car I drive has a 90 degree V6 but with additional 12 degrees offset on the big ends and a counterbalancer in the valley because the engine firing order is a bit odd, All this leads to major torque punch in the midrange right where the gearshifts occur.