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Are you guys impressed with this? I read from smarter people than myself, that 3 cylinder is actually more efficient and logical than 4cylinders. The new Fiesta ST will get about the same output from one less cylinder than the outgoing model and if that's true, the industry will likely go that route going forward. What implications does that have from tuners? Are 3 cylinders less potent than 4 netting lower yields?

I know Mini/BMW made the new Mini with a 3cylinder turbo as well. And if i"m not mistaken, I think Hyundai is coming out with a version of their own in the next year or so.
 

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This is old technology that has been tried once. True, the addition of the single two cycle in the bank is novice, but the laws of physics still remain. If you guys remember the first tiny Honda s that came here. "3" cylinders being odd are a problem over time that cannot be compensated ( Refrence to NVH).

The whole crux of this is the gas mileage craze. It will work fine I'm sure, but it wont be anything that afficionados will flock to. Durabilty over time will be quite suspect I think. I will sit back and watch others for sure.
 

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This is old technology that has been tried once. True, the addition of the single two cycle in the bank is novice, but the laws of physics still remain. If you guys remember the first tiny Honda s that came here. "3" cylinders being odd are a problem over time that cannot be compensated ( Refrence to NVH).

The whole crux of this is the gas mileage craze. It will work fine I'm sure, but it wont be anything that afficionados will flock to. Durabilty over time will be quite suspect I think. I will sit back and watch others for sure.
Gaijin - you hit the nail on the head. Three cylinder engines vibrate themselves apart. Wasn't but 20 years ago the little Chevy Sprint or whatever it was, had a 3 cylinder and GM found they weren't worth producing. Junk.
 

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Gaijin - you hit the nail on the head. Three cylinder engines vibrate themselves apart. Wasn't but 20 years ago the little Chevy Sprint or whatever it was, had a 3 cylinder and GM found they weren't worth producing. Junk.
Even with the new found measures, the problem is mathematical based. You cannot violate laws of mathematics or physics. They are trying to cpmpensate, but I am a wait and see on this one for sure.

It is why I would have a straight 6 over a V6. why a V12 is so smooth. Why the Audi/VW 5 cylinders failed.
 

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So the Volvo 5 pot in the focus rs is a ticking time bomb?


I'm not well versed but it seems lower cylinders with turbos is thr way of the future. Formula1 hybrids are making way more power than their big displacement counterparts. Yes, I know they made 1500hp from 4 cylinders in the 80s? But we're those reliable? Sure there are 2jz Flat six turbos also putting out astronomical figures but again how reliable are they? WRX sti making equally high power gains. All comes down to reliability as a daily driver. Those funny cars that do 3 or 4!second 1/4 miles need rebuilds after each pass, lol.
 

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So the Volvo 5 pot in the focus rs is a ticking time bomb?


I am just stating what has already occurred. Maybe the RS can "overcome" mathematics. Undoubtedly at the outset the RS is impressive. Time will tell.
The horzontally opposed four cylinder boxer engine is the standard for mathematical efficiency. Everyone knows somebody with a subie that has 500,000 miles.
You are correct, fewer cylinders with forced induction.

Also pushing the hp/cc reduces engine life I'm sure. Thats how I have made up my mind to do a full sleeved forged rebuild at 100,000 miles with my little monster.

DPR will be building my motor.
 

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I do not have hands on experience with 3 cylinders, but heck a lot with 2 cylinder (by Fiat) and 5 cylinder (VW).

First the little one.
It was shaky a bit. I admit. Not much of a torque at low end. Easy to stall. But it was very eager. It would rev quickly and was very light. Easy to work on.
One was air cooled - warm up times very short. Overheating basically nonexistent to my surprise. Other one was positioned on its side and was water cooled. A bit weird construction, but was very durable.
Both marked 100k miles without any major issue.

Now, to defend VW 5 cylinder.
It is a very old idea. VW has been making them since what? 1970's?
My fathers Passat had 2.0 I5. Oh man, it was very smooth (for 80's at least), plenty of power and it was indestructible. It put out 300k miles without repair. There was timing belt failure where timing jumped on or two teeth due to harmonic balancer damaging the lock. Hence, head was corrected (two slightly bent valves). Other than that - ignition issues due to failing electronics. I guess the computers were not so durable at that time.
However, mechanically it was solid.

So would 3 cylinder be a problem? I doubt it.
I do not see why Gaijin would say it is mathematical problem. Full revolution is 360 degrees. Therefore, if you got 3 cylinders you can fire them every 120 degrees, or for 5 every 72 degrees. Making two revolutions per cycle: 240 degrees fire or 144 fire. All will be balanced just like it is with 4 or 8 cylinders, I would say my Forte5 engine is less stable at idle than my fathers 1982 VW.

I bet that Fiesta with 3 cylinders would be somewhere 1.2 l, huh? I did not search the article yet, but that's what I suspect.
Also, one cylinder less - more room, less weight.
 

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I do not have hands on experience with 3 cylinders, but heck a lot with 2 cylinder (by Fiat) and 5 cylinder (VW).

First the little one.
It was shaky a bit. I admit. Not much of a torque at low end. Easy to stall. But it was very eager. It would rev quickly and was very light. Easy to work on.
One was air cooled - warm up times very short. Overheating basically nonexistent to my surprise. Other one was positioned on its side and was water cooled. A bit weird construction, but was very durable.
Both marked 100k miles without any major issue.

Now, to defend VW 5 cylinder.
It is a very old idea. VW has been making them since what? 1970's?
My fathers Passat had 2.0 I5. Oh man, it was very smooth (for 80's at least), plenty of power and it was indestructible. It put out 300k miles without repair. There was timing belt failure where timing jumped on or two teeth due to harmonic balancer damaging the lock. Hence, head was corrected (two slightly bent valves). Other than that - ignition issues due to failing electronics. I guess the computers were not so durable at that time.
However, mechanically it was solid.

So would 3 cylinder be a problem? I doubt it.
I do not see why Gaijin would say it is mathematical problem. Full revolution is 360 degrees. Therefore, if you got 3 cylinders you can fire them every 120 degrees, or for 5 every 72 degrees. Making two revolutions per cycle: 240 degrees fire or 144 fire. All will be balanced just like it is with 4 or 8 cylinders, I would say my Forte5 engine is less stable at idle than my fathers 1982 VW.

I bet that Fiesta with 3 cylinders would be somewhere 1.2 l, huh? I did not search the article yet, but that's what I suspect.
Also, one cylinder less - more room, less weight.
Hey, I'm not statig it. Just repeating it. It was explained to me by a mechanical engineer who works for Cummins engine here in Columbus. He said odd banks of cylinders cant help but produce NVH. One can dampen it,, balance it, but over time it gets to the motor.
He noted that its why so many high powered heavy equipment turbo diesel motors for heavy duty applications are straight 6s.
He was invloved in developing Nissan/ Cummins V8 turbo diesel for the Titan XD.
***I do find it interesting that the problem you did have was produced by problems from a harmonic balancer. Again NVH and its side effects.
 

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He noted that its why so many high powered heavy equipment turbo diesel motors for heavy duty applications are straight 6s.
I would disagree with his statement per NVH. All engines create NVH. Period. Even 4 cylinder, or 6 cylinder, or W16 - all must be balanced. It might be easier to balance them when the number of cylinders is even, but mathematically and mechanically I do not think number of cylinders would make it impossible.

As per I6. This is the longest engine that can be made. Well, for "regular cars" application. Six inline has very long crankshaft and it is very heavy. V6 would be about 2/3 or less of I6 length. Hence, less weight.
The counter weight of the shaft makes it so smooth. Therefore, heave powered engines, producing lots of power from cylinder, need heavy duty shafts. You can fit many bearings there. You can make it very stable. Inline 6 is nothing more, but two I3's. Am I right? Just like V6. Two I3's on two sides.

Of course inline 2 or 4 will be much easier to make that inline 3, so car makers did not even bother to develop this one. Just like inline 5 or V5. If you can make power from 2 cylinder, increase a bit more... and then just jump to well known 4 cylinder.
In two cylinder you get one coil controlling two cylinders. Coil is firing every revolution, so timing control is minimal. In 4 cylinder you get two coils. In 3 cylinder you need 3 coils... so that is already disadvantage. And many more items.

But I still cannot really justify NVH if you distribute firing order and properly counterweight the pistons using crankshaft. Just like it is done with many engines.

***I do find it interesting that the problem you did have was produced by problems from a harmonic balancer. Again NVH and its side effects.
I did not want to make long story from it. The balancer was missing a washer. A mechanic who was working on it "forgot" to install it. As a result the bolt, despite being torqued correctly, did not hold tight enough and after several thousands of km the lock got weaken to the point it let the balancer to shift (that was still unnoticed) and damage the lock even further what finally let the timing sprocket shift. And that was noticeable. :)
 

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I agree with the older technology statement. There is a reason you don't see this type of engine out there, same for the dreaded rotary engine... Who knows, maybe technology will come out later down the road that will support these types of motor. Being optimistic but unlikely, lol
 
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