Flatplane vs Crossplane - Which Is Best?

[@oscar_bru8455]

flatplane inline 4's don't have issues with primary imbalance. they do however have realy bad secondary imbalances.

[@vasilisgreen]

This! Isn't a 90° angle going to eliminate the secondary vibrations in a v8 though?

[@ahimeirhadad4836]

Right, not a flat plane in inline 4 rather in twin cylinder 180 degree and V4 Aprilia (Motorcycles).

[@advxyz1877]

Bro that is untrue, inline 4's are have perfect primary balance, but they have ok-ish secondary imbalance, I say this because when all pistons are at either TDC or BDC, they have a net upward force (Because all pistons will have upward secondary forces), whereas when they are all at 90 or 270 degrees through their stroke they have a net downward force (Because all pistons will have downward secondary forces). Even though they do not balance out, they are considered fine and not "really bad" in their secondary imbalance as they do not produce a rocking couple.

[@johnnysodak7261]

@@advxyz1877 and that ladies and gentlemen is a reason why we rarely see I4 bigger than 2,5 or FPV8 over 4,5 l of displacement. Because those OKish secondary vibrations would shake them or the car apart.

[@ClassicTVMan1981X]

I prefer the crossplane V-8 sound myself... nothing else comes near! Detroit Diesel also used a crossplane crank for its 4-71 inline-4 two-cycle diesel engine!

[@77PacerStudios]

I happen to be more fond of the cross-plane V8! I can't think of an engine that can produce a sound as good as a cross-plane V8!

[@danmaycock9238]

What about a crossplane V8 with UELs?

[@themacsthecameraman5383]

One example in video for everything - Ferrari V8!!!! NOTHING sounds better than Ferrari V8 ... US V8 aren't even close!

[@highskale]

I agree! 100% nothing sounds as good as a cross plane crankshaft v8 engine.

[@geoffpace8981]

very interesting ,those flashing lights and speeding up the timing works well .

[@vasilisgreen]

So much misinformation. A flat plane crank has PERFECT primary balance. The secondary imbalance is caused by the stroke itself because the piston doesn't move with a constant speed and instead the connecting rod itself pulls on it and then pushes on it because of its angle. A flat plane crank shaft has BOTH primary AND secondary imbalances and it's actually HARDER to balance out and that's why a cross plane crank shaft is thicker and heavier with various balance shafts. In a v8 configuration, the cross plane will achieve secondary balance IF it's a 90° V but its primary balance will still be shitty and require heavy counterweights. The reason that cross plane exists in i4 engines is to space out firings and give tyres more time to recover similar to a shared pin v4. In v8 engines the only advantage of a cross plane is the lack of secondary vibrations. Exhaust pulses have nothing to do with what RPMs the engine is happy at and crankshaft design has nothing to do with where the torque comes in. You can make a flat plane engine have torque down low and a cross plane to have all its power at peak RPMs. Exhaust scavenging works to enhance the power band of an engine and maybe even broaden it, it doesn't change it. What is inherent to crankshaft design is peak RPM, not the powerband. While a cross plane will peak at around 7 to 7.5k RPM, it can be set to have its power come that high and at the same time a flat plane will naturally rev to 9.5-10k RPM but it can be set to have its power come in much lower in the power band, it's just not optimal. Firing interval is different in i4 engines between flat and cross plane but in a 90° v8 engines, both crank shaft designs have a firing pulse every 90° of crank shaft rotation, it's just that the interval is irregular per bank and that's why exhaust scavenging is sub optimal in cross plane v8s, because the headers are split into two banks. If you join the exhaust headers down the line into one pipe, both engines will sound the same. A cross plane crank i4 does not have a smoother power delivery, it has a more docile power delivery, because of the irregularly spaced power pulses, contrary to a flat plane, which has evenly spaced power pulses and it does indeed have a smooth power delivery. The advantage of the cross plane is that, like mentioned above, it gives the tires more time to recover grip because of the longer pause and helps manage the power easier than the constant power stream of a flat plane. This advantage only applies to motorcycles because they have very limited grip. In v8 engines both crank shaft configurations have the same power delivery. Seriously, do not spread so much misinformation.

[@geoff2176]

That is real thorough explanation,thanks

[@GoingtoHecq]

I was looking at the times very carefully on the cross plane one. The pistons are staggered much more. Beyond that it was hard to know anything but my experience with engines suggesting that more torque from this is maybe not something I expect.

[@vasilisgreen]

@@GoingtoHecq The torque of an engine is only a product of the force pushing down the piston times the length of the crank throw. It has nothing to do with engine layout.

[@Freebyrd1991]

"A flat plane crankshaft has perfect primary balance"...."A flat plane crankshaft has BOTH primary and secondary imbalances" I think you need to edit again otherwise you are spreading misinformation too.Not trying to be an asshole, just something I noticed.

[@amisfitpuivk]

Good read. It makes sense with the V8s that they aren't nearly as different compared to the flat plane inline 4 vs Yamaha's crossplane. V8 has the cylinder count where flat and crossplane can both evenly fire, and that's interesting that if you pipe the exhaust a certain way they'd both sound the same, it makes sense since the spacing between firing is the same and should produce the same frequency sound if the piping converges evenly. I'm guessing it's just impractical to do that and the pipe would be huge.

[@causeimbatmaaan]

Cross plane was the answer to weak flat plane cranks in the first place. Cross plane crank engines are capable of more overall power by about double no matter how well suited materials become. It's just a superior design durability wise. With low power engines you may as well save on material quantity so a flat plane will do.

[@jonelford]

Cross plane crankshafts are used for balance reasons, not for power handling.

[@causeimbatmaaan]

@@jonelford For both actually.

[@jonelford]

@@causeimbatmaaanA property built flat plane will handle just as much power as a cross plane crank.

[@causeimbatmaaan]

@@jonelford No. Just...no.

[@jonelford]

@@causeimbatmaaan You seem so confident. There must be some reason for that.

[@C100pro.guy.]

That dyno vid of that stang is a flat plane crank engine 5.2 foodoo coyote

[@Nam_9456]

I was just thinking that lmao

[@sma7530]

I learnt a lot today. Thanks

[@Lotusvvc]

Hi. Very good video - thanks for that. Could you include a simulation - and the soundtrack - of a V12 (e.g. Jaguar V12) in a future video, please? Thanks. Peter

[@genius.stream]

Thank you, very informative

[@Latuya-y1n]

Inline 6 4 to 2 crankshaft compression instead 222 to get full engine compression two spins instead of 3 n v8 4 to 4 crankshaft

[@leximatic]

I like the more growling sound of the crossplane.

[@SeatLeonMK2]

Crossplane makes 4 torque rotations and flatplane 2, this can be an advantage or disadvantage

[@vasilisgreen]

what?

[@johnnysodak7261]

what are you talking about ?

[@SeatLeonMK2]

every rotation of the crankshaft gives 4 pulls flatplane 2 because of 180 degree

[@vasilisgreen]

@@SeatLeonMK2 you either have no clue about the topic or you need to go to school to learn proper English.

[@jonelford]

@@SeatLeonMK2No. Both give 4 power pulses per crank revolution.

[@michaelbrunson3636]

you showed a gt350 during the sound display but a Gt350 is a flat plain crank engine

[@AntonioMorales-sk3df]

I came looking for this

[@ArneChristianRosenfeldt]

Why isn’t there a poll?

[@ahimeirhadad4836]

2:45 Sorry, not a flat plane crank i4 rather in twin cylinder 180 degree and V4 of the Aprilia but if is car the best sound = twin cylinder 180 degree and V4 Aprilia (Motorcycles). 3:41 Half crossplane (Engine Sound) half flatplane (Exhaust Sound)!

[@advxyz1877]

Bro Inline 4's have perfect primary balance.

[@TineFangaming]

Yamaha R1

[@ar2043]

Cross plane all the way!!!

[@mynameisPhoenixSteele]

That Mustang has a flat plane. Most of this video was incorrect.

[@TheTbet]

Crossplane are a mess is balance and firing order, they cannot rev over 6000rpm, giant counterbalance on giant crankshaft, big space big weight, they got nice sounds for the consecutive double firing per bank.

[@kimnielsen3111]

I will always be crossplane fan its my favorite 👌🤤

[@noanyobiseniss7462]

That was on shitty sounding v8, you should have used a chevy.

[@adrianwolff2007]

Wrong information

[@jesusperezerazo]

I prefer wankel engine

[@SeatLeonMK2]

that's a not so smart choice

[@johnnysodak7261]

I4 doesnt have primary vibration issue, secondary vibration not caused by "crankpin weight" and crossplane i4 doesnt have "smoother power delivery" - quite the opposite in reality. Uneven pulses = uneven torque delivery... wtf is this nonsense :D

[@amisfitpuivk]

Maybe the crossplane R1 power delivery doesn't appear smooth on paper/rhythmically, but in practice that innate traction control from the gap in the firing interval could make the power feel smoother, especially at lean where it counts most. So it could be smoother with all things considered even though in a vacuum it looks stuttery. Only a professional racer with experience on a lot of bikes could answer that one though

[@johnnysodak7261]

@@amisfitpuivk Yes, the feeling on motorbike can be like you said (thats the primary reason tehy are doing it anyway) but if you ask me if uneven firing straight 4 has smooth power delivery, the response is no. Ask the transmission.. :D

[@trueno8663]

Flat plane V8's sound like glorified 4 cylinders. The Ferrari flat plane V8 sound does nothing for me.

[@slavtrooper3851]

They literally are glorified 2 cylinders sound-wise. The real difference is the cross plane is growly and flat plane screaming. I'll always take the flat plane over the cross but that's down to personal preference.

[@TetraHax]

Crossplane I4's have poor primary and secondary balance