Porsche doesn't us the same crank pins for opposing cilinders. First animation is a 180° V design, the second one a boxer engine (which is what Porsche uses)
Exactly. Only 180°V that I know of was a Ferrari engine from Testarossa. But that one was a 12 cylinder, and as every V12 is inherently balanced, bocer doesn't have its big advantage at this point.
Boxer engine ... so cool ... two big benefits: needs less space ... less vibrations. The BMW motor bikes still have boxer engines if I remember right. German police used them. Very reliable bikes. Did Porsche use the boxer even without water cooling ? I think the first models had been air cooled, too.
The Porsche engine has a much lower crankshaft mass, also fewer friction because of only 3 main bearings which is in both cases is a sign for a higher achievable number of revolutions per minute. Porsche is famous for its revving engines which gives the car a fast acceleration.
The boxer suffers from high windage and crankcase pressure. This reduces performance particularly in high revving applications. If we are talking two stroke then it’s a different situation. This becomes an advantage.
No sir. It doesn’t suffer from high windage, most motors have a windage tray. And how would their be more crankcase pressure if there is more volume for movement in the crankcase to compensate for a longer crankshaft? 😂😂. Plus! There are pcv systems DESIGNED to regulate the crankcase pressure. Don’t comment so confidently if you don’t know. You are right tho the flat engine is faster BUT your reasons are wrong. There is less material on the crank and it is more balanced (stroke wise) and now that i am seeing it, they look like flat plane cranks too which is always a plus.
@@LowkeyBanger maybe I’m an idiot, but Fritz Indra said so much on an episode of Alte Schule. To paraphrase him: there is a reason we’ve never seen a high performance engine in a boxer configuration.
@@robertmaier8959 really? The 992 911 turbo s has a 3.8l flat 6 and run 10 seconds to the 1/4 mile STOCK. Even the 918 super car has a hard time keeping up. As I said, do your research please before you start yapping. Ya yapperdoodle.
Flat engines and boxer engines are both horizontally opposed engines that have their cylinders arranged in a flat configuration, but there are some key differences between them: 1) Cylinder orientation: In a flat engine, the cylinders are arranged in two banks that are directly opposite each other and lie in the same plane, whereas in a boxer engine, the cylinders are arranged in two banks that are angled towards each other and lie in different planes. 2) Combustion characteristics: Due to the cylinder orientation, the combustion characteristics of the two engine types differ. Flat engines tend to have a more traditional combustion pattern, while boxer engines have a more efficient combustion process due to their angled cylinder layout. 3) Size and weight: Boxer engines are typically larger and heavier than flat engines of the same displacement, as the angled cylinder configuration requires additional space and components. 4) Balance: Boxer engines have a better inherent balance due to the opposing pistons canceling out each other's vibrations, resulting in a smoother operation than flat engines. 5) Sound: Boxer engines produce a distinct, low-frequency rumble, while flat engines produce a higher-pitched sound.
Top engine is simpler with only 3 main bearings, but will suffer from bad vibration. Bottom engine vibrates less but is too long because it has 5 main bearings. Best option is boxer with 3 main bearings.
Dude. How is it more balanced than 1? The cylinder “1,2” moves in tandem then “3,4”. Hence why they need more counterbalances on the crank and much more crank material. On engine 1 “1,3” and “2,4” they are moving in tandem canceling each other out. TH-cam comments can be so silly sometimes. You’re so confident yet wrong.
I don’t see any reason why one would be more powerful than the other. But the bottom has 2 extra mains on the crankshaft to spread the stress out over a larger area, which would make a longer lasting engine.
The subaru engine is more balanced, reducing wear and increasing the potential redline (when modded). Some lunatics made a subaru boxer rev to 12,000 safely
it is the same the only difference is the crankshaft is longer on the Subaru and each connecting rod has its own counterbalance which makes more rotational Force the Porsche makes more power because there's less counterbalancers
With my toddler level knowledge. I’m going to make my best guess and say the top one for three reasons. 1) It obviously weighs less 2) it doesn’t have a section for each piston so wouldn’t there be less moving parts, less friction, less heat and less energy lost. 3) it seems like on the flat engine the pistons are helping each other go up and down whereas the boxer engine, each piston is doing its own work.
almost, but the last one is not really a point as the whole crankshaft is still one piece, so every piston going down pushes a piston up, maybe - some friction and some winding
@Wfsyr739 top engine has cylinder pairs sharing crank pins, meaning the engine vibrates on its cylinder plane as the piston pairs reciprocate. The lower engine each piston has its own crank journal and piston pairs move opposite to one another, canceling each other's momentum, running smoother.
The difference has nothing to do with "power". The larger engine is more powerful regardless of the type. Having said that, boxer engines have a lot less radial vibrations because each couple of close pistons move constantly in opposite directions.
A little study on the flat, shows me there might be some room for optimization. Boxer relies upon full separation, which might demand strengthening of displacement along the longitudinal axis of the drive shaft. The goal of all this is to minimize this while providing resistance to create vectoring into torque.
I know that the little air cooled vw flat motor was almost bulletproof. A short, forged crank, not cast. Unfortunately not enough counterweight for reliable high revs in a magnesium case. So you weld extra weight on the crank. Some go full circle. No head gasket to worry about on the a.c. motor. A 1600cc motor can be taken out to about 2.5 litres. But with a small crankcase you can get alot of oil leaks because of windage. They were basically like a detuned motorbike engine, with alot of potential.
You guys all must be joking right the porsche engine obviously has more power and less weight, but it depends what you want low rpms or high rpms the porsche engine is good at getting to high rpms where as the boxer engine excells at reliability and lower rpms
What we can learn on tiktok surprises me every day.😮 Didnt know subaru used boxers. Only know this car brand from ralley sports being very successful in world championships
The top engine will rev's quicker. Due to less internal inertia... The bottom engine has more torque. Due to more internal momentum. The Top engine will hit max power sooner, but the bottom engine will have more total power later. Giving the Bottom more average total power across the total power band.
Power has everything to do with size displacement. Which ever displaces more will have more power, the different setups have more to do with vibrations. The top will be lighter but probably have more flex. The bottom might have more toque it's hard to say.
From a weight stand point the bottom will defiantly weigh more so total power could be affected if weight is an issue. I do agree the top would rev quicker. The bottom would probably have more torque.
@@Phantom8589 The more abundant counter weights on the bottom engine, means more moment... Angular momentum to be exact... Torque is simply the rate of change in angular momentum.
Boxer engines Or flat depending who ur talking to Pros Low center of gravity Decent torque Decent economy Cons Short lifespans due to design making oiling efficiency poor, avg life 120k miles with regular maintenance
The first ones more like the continental engine does 150hp na while subs do 120hp na …. Hence lighter internals is the way for more power na … but if you want to boost it, go with the boxer its got the strength
Flat Engines more Powerful . less components , less moving parts and opposing combustion system , simple mechanical application , and finally : less weight .
top can probably run on less compression ratio with lower grade gasoline perhaps? and also its space efficient so u can add more cylinder and rev high rpm much faster but redline quicker, not an engineer either feel free to correct me if im wrong
The Subaru boxer engine is better at performing on high RPM caused by that 2 piston's fire simultaneously and the resulting down forces "help"the piston on the opposite side👍 also the sound is crazy
Yeah but no. A 180° V engine is also called flat engine. Boxer means that every piston have its own bearing, and of course it is also a flat engine but the first one is a flat engine too. Although this fact, the video is false. Porsche is not using regular flat engines, nor 4 cylinder ones. This kind of V makes no sense in a 4 cylinder engine because of the horrible balance it has.
With periods like this porshes must have less vibrations, besides it should be lighter as whole mechanism takes less place and therefore less metal needed so more ptwr
1 would have more angular stress on crank, however it has less weight to turn. Maybe 1 rev. faster with slightly more vibration. But the shorter crank shaft would help compensate for uneven forces. - But 2 might be a better design for longevity and may rev just as fast considering it does not need to be as strong and heavy to deal with angular apposing forces. 2 may in fact last longer. With more bearings to stread out the forces.
Its the same... What you tryna prove and since we doing this, add the VW Beetle 1303S and whatever that one Alfa Romeo was with a boxer engine. Porsches calls it flat engine cuz they want the quirky
Both are good, but there are pros and cons with each design. I get the impression that the top one is more energy efficient, but if there's ever a problem with one of the cylinders, another will effected. With the bottom one, power and force will be evenly distributed throughout the engine, but it just won't be as powerful. Still good design though. I get the impression I'd get more power from the top one, but at the same time, more problems if something got damaged
Lower one lasts longer. You could still increase the bore, less cooling issues. Don’t need to worry about block facility as much as the one above. The upper one is more efficient. Weighs less. Won’t last as long.
Top, Porsche builds some of the BEST flat 4's... and no, its not a "boxer" engine, a boxers pistons dont move away from each other, a boxers pistons move twd eachother hence the name BOXER, it looks like 2 sets of pistons are BOXING eachother...
Porsche doesn't us the same crank pins for opposing cilinders. First animation is a 180° V design, the second one a boxer engine (which is what Porsche uses)
I love misinformation. Let’s all play the telephone game.
Exactly. Only 180°V that I know of was a Ferrari engine from Testarossa. But that one was a 12 cylinder, and as every V12 is inherently balanced, bocer doesn't have its big advantage at this point.
A boxer engine has 2 pistons sharing the same cylinder heading twds eachother, hence the name boxer...
Porsche 919…
WHAT?
Boxer engine ... so cool ... two big benefits: needs less space ... less vibrations. The BMW motor bikes still have boxer engines if I remember right. German police used them. Very reliable bikes. Did Porsche use the boxer even without water cooling ? I think the first models had been air cooled, too.
yes, the early boxer engines by porsche/vw back in the day were all air cooled.
The amount of spaces used here is crazy
Flat v would take less space 2 cilinders for every crank
The VW Beetle was also air cooled
Less space?
Bottom. Better balance and less stress. It’s the stronger engine. Two extra crank bearings. Less flex. Can make more power.
🤔Ya sure about that? The Subaru engines don't like high rpm's where as the Porsches are known screamers!
@@mayhemmike1789screamers... But not more power.
Top end performance proves the opposite is in fact true! 🥃
The Porsche engine has a much lower crankshaft mass, also fewer friction because of only 3 main bearings which is in both cases is a sign for a higher achievable number of revolutions per minute. Porsche is famous for its revving engines which gives the car a fast acceleration.
Pretty sure a longer crank causes more flex
The boxer suffers from high windage and crankcase pressure. This reduces performance particularly in high revving applications. If we are talking two stroke then it’s a different situation. This becomes an advantage.
No sir. It doesn’t suffer from high windage, most motors have a windage tray. And how would their be more crankcase pressure if there is more volume for movement in the crankcase to compensate for a longer crankshaft? 😂😂. Plus! There are pcv systems DESIGNED to regulate the crankcase pressure. Don’t comment so confidently if you don’t know. You are right tho the flat engine is faster BUT your reasons are wrong. There is less material on the crank and it is more balanced (stroke wise) and now that i am seeing it, they look like flat plane cranks too which is always a plus.
@@LowkeyBanger maybe I’m an idiot, but Fritz Indra said so much on an episode of Alte Schule. To paraphrase him: there is a reason we’ve never seen a high performance engine in a boxer configuration.
I was wondering what country haa the 2 stroke subaru.
@@robertmaier8959 really? The 992 911 turbo s has a 3.8l flat 6 and run 10 seconds to the 1/4 mile STOCK. Even the 918 super car has a hard time keeping up. As I said, do your research please before you start yapping. Ya yapperdoodle.
@@LowkeyBanger less rocking moment to sap energy
Flat engines and boxer engines are both horizontally opposed engines that have their cylinders arranged in a flat configuration, but there are some key differences between them:
1) Cylinder orientation: In a flat engine, the cylinders are arranged in two banks that are directly opposite each other and lie in the same plane, whereas in a boxer engine, the cylinders are arranged in two banks that are angled towards each other and lie in different planes.
2) Combustion characteristics: Due to the cylinder orientation, the combustion characteristics of the two engine types differ. Flat engines tend to have a more traditional combustion pattern, while boxer engines have a more efficient combustion process due to their angled cylinder layout.
3) Size and weight: Boxer engines are typically larger and heavier than flat engines of the same displacement, as the angled cylinder configuration requires additional space and components.
4) Balance: Boxer engines have a better inherent balance due to the opposing pistons canceling out each other's vibrations, resulting in a smoother operation than flat engines.
5) Sound: Boxer engines produce a distinct, low-frequency rumble, while flat engines produce a higher-pitched sound.
U used chatgpt to write this
@@ethancampbell2762 you german people?
@@erika9605 wut
Wow...technology 🎉🎉
@@ethancampbell2762 what?
Correct question is which will blow head gaskets quicker?
I approve this message
Most underrated comment😂
💯 😂
Answer?
@@chadbrown5541i bet on the top one.
Which number is higher 175 or 230
my brother owns a Subaru. a lot of power comes out of their relatively small engines
Flat less weight more reliable
Toper one for speed lower one for torque
Top engine is simpler with only 3 main bearings, but will suffer from bad vibration. Bottom engine vibrates less but is too long because it has 5 main bearings. Best option is boxer with 3 main bearings.
The question isnt whats better, its what is more powerful, both equal
The below one is more powerfull, beside it has less vibration and distributes force and equalized vector
Yeah, Porsche is definitely more powerful then Subaru... u must not know much about how Porsche builds there motors
Dude. How is it more balanced than 1? The cylinder “1,2” moves in tandem then “3,4”. Hence why they need more counterbalances on the crank and much more crank material. On engine 1 “1,3” and “2,4” they are moving in tandem canceling each other out. TH-cam comments can be so silly sometimes. You’re so confident yet wrong.
What's your vector victor😂😂😂😂 Z Germans will always out do the jdms
Longways for results sideways for attention
top one for speed lower one for strong
Boxer has better primary balance and can theoretically rev higher for more power so that one
Flat engine produced way more compression, better stroke. Overall better design.
I think the torque of the top will be higher and the speed of the bottom one will be higher.
Subaru uses its entire stroke, and has the rods on their own bearings and not sharing with another rod
So does everything else
@@donniebaker5984the flat engine in video doesn't have that.
How can a engine not use its entire stroke😅?
porsche flat is compact + no vibration + powerful.
Never seen such bs before. Porsche is THE manufacturer of Sechszylinder Boxermotoren in all their 911s.
I don’t see any reason why one would be more powerful than the other. But the bottom has 2 extra mains on the crankshaft to spread the stress out over a larger area, which would make a longer lasting engine.
The subaru engine is more balanced, reducing wear and increasing the potential redline (when modded). Some lunatics made a subaru boxer rev to 12,000 safely
There's less reciprocating mass and it can rev higher
Smaller counterbalance means faster revolution but more vibration. Perhaps subaru adds more CB for smoother in compromise to slower revving.
I'd say the flat one is stronger, but the boxer is more stable so it would be a better option for safety
Opposed piston should be with scavenging and ventilating mechanically forcing😊
The first one, it has less weight
it is the same the only difference is the crankshaft is longer on the Subaru and each connecting rod has its own counterbalance which makes more rotational Force the Porsche makes more power because there's less counterbalancers
A strong crank isn't worth crap of you can't keep a head on it .
Or rings.
With my toddler level knowledge. I’m going to make my best guess and say the top one for three reasons. 1) It obviously weighs less 2) it doesn’t have a section for each piston so wouldn’t there be less moving parts, less friction, less heat and less energy lost. 3) it seems like on the flat engine the pistons are helping each other go up and down whereas the boxer engine, each piston is doing its own work.
almost, but the last one is not really a point as the whole crankshaft is still one piece, so every piston going down pushes a piston up, maybe - some friction and some winding
Subaru design layout is much better I think...
“Corporate needs you to find the difference between this picture and this picture.”
“They’re the same picture.”
That's what a blind person would say.
@@andreazoninThey+re the sma epkctue
No, top engine has 2 cylinders firing together, bottom each of the 4 fire separately with much less vibration and more power
@Wfsyr739 top engine has cylinder pairs sharing crank pins, meaning the engine vibrates on its cylinder plane as the piston pairs reciprocate.
The lower engine each piston has its own crank journal and piston pairs move opposite to one another, canceling each other's momentum, running smoother.
Well no, the top one has 2 pistons interconnected for both, and the bottom has an independent piece for each.
Flat engine, because this is more smooth and almost straight than the other
NO . 2 Larger engine longer
cam .
Boxer vs flat is irrelevant to power. Boxer has better balance, but power depends on a bunch of other factors aside from this one aspect.
1st design 🎉
The difference has nothing to do with "power". The larger engine is more powerful regardless of the type. Having said that, boxer engines have a lot less radial vibrations because each couple of close pistons move constantly in opposite directions.
I have a v6 with way more power than a much larger v8. How did that happen lol?😂
@@thehulkamaniabrother2.089 - Here we compare flat vs. boxer and you come to compare the number of cylinders? Have a better look at the video, dude...
This guy know how to start an argument over the Internet all I'm saying
A little study on the flat, shows me there might be some room for optimization. Boxer relies upon full separation, which might demand strengthening of displacement along the longitudinal axis of the drive shaft. The goal of all this is to minimize this while providing resistance to create vectoring into torque.
I know that the little air cooled vw flat motor was almost bulletproof. A short, forged crank, not cast. Unfortunately not enough counterweight for reliable high revs in a magnesium case. So you weld extra weight on the crank. Some go full circle. No head gasket to worry about on the a.c. motor. A 1600cc motor can be taken out to about 2.5 litres. But with a small crankcase you can get alot of oil leaks because of windage. They were basically like a detuned motorbike engine, with alot of potential.
上のは180°V型エンジンでボクサーエンジンではない。
ポルシェのエンジンではない。
ポルシェのエンジンとスバルのエンジンは同じ動き。
Looks like there’s less energy lost with the first one. Wish the answer were shown at the end of the video
Subaru because it has a fly wheel and runs smoother
You guys all must be joking right the porsche engine obviously has more power and less weight, but it depends what you want low rpms or high rpms the porsche engine is good at getting to high rpms where as the boxer engine excells at reliability and lower rpms
As much as I’m a Porsche fan, the Subaru’s boxer looks promising and efficient.
What we can learn on tiktok surprises me every day.😮 Didnt know subaru used boxers. Only know this car brand from ralley sports being very successful in world championships
The top engine will rev's quicker. Due to less internal inertia... The bottom engine has more torque. Due to more internal momentum. The Top engine will hit max power sooner, but the bottom engine will have more total power later. Giving the Bottom more average total power across the total power band.
Power has everything to do with size displacement. Which ever displaces more will have more power, the different setups have more to do with vibrations. The top will be lighter but probably have more flex. The bottom might have more toque it's hard to say.
From a weight stand point the bottom will defiantly weigh more so total power could be affected if weight is an issue. I do agree the top would rev quicker. The bottom would probably have more torque.
@@Phantom8589 The more abundant counter weights on the bottom engine, means more moment... Angular momentum to be exact... Torque is simply the rate of change in angular momentum.
I would guess that the upper engine is more powerful
Porsche also will you a BOXER 6, so though Subbies are sick, there's no replacement for displacement
Boxer engines
Or flat depending who ur talking to
Pros
Low center of gravity
Decent torque
Decent economy
Cons
Short lifespans due to design making oiling efficiency poor, avg life 120k miles with regular maintenance
Bottom one should be better because if you look from the side movements are more smooth and torque is better
WRONG.
I don’t know which one but I love Porsche.
The first ones more like the continental engine does 150hp na while subs do 120hp na …. Hence lighter internals is the way for more power na … but if you want to boost it, go with the boxer its got the strength
Flat Engines more Powerful .
less components , less moving parts and opposing combustion system , simple mechanical application , and finally : less weight .
Not an engineer, but to me it looks like the top has less inertia, making it more efficient in real use.
top can probably run on less compression ratio with lower grade gasoline perhaps? and also its space efficient
so u can add more cylinder and rev high rpm much faster but redline quicker,
not an engineer either feel free to correct me if im wrong
Flat is more powerful but boxer is smoother.
Which one is more efficient ?
Impossible to say without bore,stroke informatio
The Subaru boxer engine is better at performing on high RPM caused by that 2 piston's fire simultaneously and the resulting down forces "help"the piston on the opposite side👍 also the sound is crazy
Subaru is not a big bang engine. 2 cylinders do not fire at the same time
Subaru isn't a boxer! It's a v 180! 🙄
@@NickTheQuick82 Wdym? Subaru uses boxers?
@@NickTheQuick82
It's a boxer.
boxer engine - the crank shaft can break if one piston seizes due to torqueing..flat wil not break
Só que na primeira versão vai forçar bem mais o eixo. Mais funciona se for mais grosso e reforçado
Porsche use Boxer configuration, "Flat engine" is just for naming
Depends on intake ,number of valves
Bore x stroke
Fuel type supercharged or not …
Depends on the cam and displacement.
I would assume they are using the same cams and displacement for scientific observation.
Depends upon the firing order.
Every 90 degrees or 180 degrees.
You mean flat 180° V-engines. Porsches "flat" is a boxer engine, so the pistons working against each other. The top one is a V 180°, not a flat/boxer
The number of shorts like this, completely fake 🙄
Yeah but no. A 180° V engine is also called flat engine. Boxer means that every piston have its own bearing, and of course it is also a flat engine but the first one is a flat engine too. Although this fact, the video is false. Porsche is not using regular flat engines, nor 4 cylinder ones. This kind of V makes no sense in a 4 cylinder engine because of the horrible balance it has.
Your eyes are crossed ..you should get something done about that
How many v's do you guys see that are flat ???
A boxer engine is always a flat engine. But a flat engine isn't always a boxer engine.
Top, bottom would have more tensions… honestly the quality and kind of metal not implied kind of alternates my decision…
same,because all this motion was balance.the only different ~size &cost &metal strength.
I don't know which one is more powerful but I know which 1 will fit into a smaller space
المحرك الصندوق اختراع سوبارو بالأساس لكنها أعطت ترخيص لبورش لاستخدامه في سياراتها
With periods like this porshes must have less vibrations, besides it should be lighter as whole mechanism takes less place and therefore less metal needed so more ptwr
1 would have more angular stress on crank, however it has less weight to turn. Maybe 1 rev. faster with slightly more vibration. But the shorter crank shaft would help compensate for uneven forces.
- But 2 might be a better design for longevity and may rev just as fast considering it does not need to be as strong and heavy to deal with angular apposing forces.
2 may in fact last longer. With more bearings to stread out the forces.
WRONG
Оппозит, невероятно тяговитый💪
Its the same... What you tryna prove and since we doing this, add the VW Beetle 1303S and whatever that one Alfa Romeo was with a boxer engine. Porsches calls it flat engine cuz they want the quirky
I have no clue tbh. Both look intriguing though.
Igual, si la gestión del motor es la misma. Solo cambia la torsión del cigüeñal
Flat has three main journals so the crank is inherently weaker. Boater has 5 so you can crank up the power with impunity
Remember!...who is the greatest at lemans
Porsche no longer uses the top engine but they didn't use it for power they used it to save space and make the engine lighter
Both share the benefits of a flat plane design. And the detriments.
Na górze mamy silnik w układzie V a na dole Bokser. Myślę że bokser zawsze mocniejszy.
boxer, since it has less vibration
Option 1: = high Kw
Option 2: = more talk
Both are good, but there are pros and cons with each design.
I get the impression that the top one is more energy efficient, but if there's ever a problem with one of the cylinders, another will effected.
With the bottom one, power and force will be evenly distributed throughout the engine, but it just won't be as powerful. Still good design though.
I get the impression I'd get more power from the top one, but at the same time, more problems if something got damaged
Lower one lasts longer.
You could still increase the bore, less cooling issues. Don’t need to worry about block facility as much as the one above.
The upper one is more efficient.
Weighs less. Won’t last as long.
The boxer sounds nicer
1st with two big turbos. Basically my car lol
Flat engine would have way less vibration
Second one. Because freely moving
ещё лучше когда толкатели на одной оси
Top, Porsche builds some of the BEST flat 4's... and no, its not a "boxer" engine, a boxers pistons dont move away from each other, a boxers pistons move twd eachother hence the name BOXER, it looks like 2 sets of pistons are BOXING eachother...
Bottom one has more power but top is more reliable in long term. Less moving parts, less to break
The music is a deterrent
I realized that the crankshaft of a boxer engine moves in the same way as an inline four-cylinder engine
Awesome 💯
Flat
If the Porsche ones are connected to the same thing anyway couldn’t they be opposite each other?
Idk about power, but top one is mpre stable
Team boxer
One definitely spins faster and since HP is proportional to RPM. The one that spins faster is probably more powerful
Subaru.
Boxers have better balance and it's perfect but flat doesn't have perfect balance
I’m assuming the top one is more powerful because of its compact design leading to less mass for the pistons to move
😮Subaru offer more balancing😊
More balancing ? Its eIther balanced or its not ...the number or configuration of pistons can be dynamically balanced
More information is needed... also what years are these motors?