Excellent video ! The truth is that I don't understand why it worked with the Porsche RS spyder and why it doesn't work with the 963, it is supposed to be very sophisticated, obviously adding the turbos added to the electrical part that must be much more delicate is causing serious problems. vibrations to those of Porsche, because this is a very big change for an engine. It's almost like designing a new engine.
not rly just change the firing order camshaft(4) and crankshaft the rest is the same if it's a change to the hot V or cold V then that's when u start basically designing a new engine
This subject has been debated for years on motorcycles because its about power pulses and wheel coasting. The tyres need time to slip and grip between power pulses to pull out of corners faster with less tyre wear. Yamaha knows whats up if you look at their cranks. Thanking this channel for great engineering reviews, good work guys.
Yamaha USED to know, just look since 2016-17 Rossi complaining about having no traction and the wheels just spinning while having the LEAST powerful bike in MOTO GP.
@@Random63R400 While it's true that Yamaha has been underperforming, it is worth mentioning that practically every other manufacturer switched to an uneven firing V4.
@@yummyhershey5902 Because you can make more power and they don't have traction issues like Yamaha does (even Suzuki with their inline 4 had more power and control), so the crossplane concept found it's limit or something else cause they aren't the best anymore.
I like the idea. Hope they succeed. But I wonder if they could also decrease the engine stroke a bit, reducing the piston's speed and allowing it to run more smoothly and rev higher AND faster. Sure, they'd lose some displacement, therefore power and torque, potentially, but they could compensate that with more boost or extra power from the electric motors.
@@dylanhaili5646 Yeah, but considering it runs under boost, it's best to keep the bore stock. A larger bore would mean thinner cylinder walls, potentially compromising the block's structural integrity.
Great video as per usual, as a mechanical engineering student in Ireland, having studied for a semester in Darmstadt, DE, your videos are very informative and insightful
I actually heard the Porsche yesterday and it sounded like a cross plane. Cadillac figured that out last year since the engine is attached solidly. The vet has a softer sprung engine so it can use a flat plane. And yes, 180deg headers can change the sound but it doesn’t solve the vibration problem and adds weight. Example: GT40s ---> TMYK.
what are you talking about? Cadillic has never run a flat-plane crank and have aways run a cross-plane and it wasn't until the C8.r that any GM brand entertained a flat-plane crank. They didn't just figure anything out as these issues have been common knowledge for half a century now.
@@rolandotillit2867 I dont think the 90 degree bank angle used by teams because its the most vibration prone engine. It is chosen as it is dictated by the technical rule set. Otherwise any angle other than 120 degrees is either a well thought out compromise (eg. for aero gains and other space constraints) at best and poor design at worst.
Interesting twist there, as the top street versions of Corvette and Mustang recently have been changed in the opposite direction - from cross- to flatplane 😮
They'll have to allow it, otherwise Porsche are likely to pull out. Most series have reliability fix clauses, but they are generally to fix the components that are breaking, not so much a normally functioning component breaking other's, so it's an interesting question!
I hope Porsche will be allowed to switch to a crossplane. They could still use a hot v and route the exhaust gases in a way that the two turbos are evenly loaded with the exhaust pulses despite being a crossplane; BMW did that in a very elegant manner with its hot v street car v8s more than 10 years ago.
I have a thought about the V4 they use on 919. What if they reduced the displacement to 1 liter and used its design to help Yamaha or maybe Aprillia. Though gearbox will be an issue, I think they can pull it of
Wow, the world is coming around to cross plain being the superior configuration, you could almost say the American muscle cars had it right the whole time.
So they had this problem with the 919 Flat four during early testing, and again the same thing ? i know it's hard to predict if a design will generate vibrations, given the fact they all test theire engine in single piston design (so no harmonics), but it's 2024... Honda had the same issue in 2017 in F1.
Someone please explain why this crankshaft change to crossplane WOULD NOT be approved? Porsche isn't increasing displacement, just changing firing order for smoother operation at higher RPMs. Always thought crossplane sounded better anyway, see the Yamaha R1...
It most likely will. ACO is very lenient when it comes to safety or reliability related changes so it’s more than likely they will be able to do this without using one of their evo upgrades.
I don’t recall how the upgrades work in LMDh. Are they only permitted reliability upgrades or do they have a certain amount of “jokers” over the duration of the regulations?
Will the 963 ever be allowed to challenge the 919 Lap record on the Nürburgring? Any thoughts on this? Naturally only once it's not in the racing business that is. They could also go off and do anything needed to beat that incredible record held.
@@Explosivo93 Time will tell. The 919 was totally unconstricted and prepped for the Ring. Had over 1100 hp afaik. This could be achieved with the 963 if they will do to it what they did with the 919. But who would drive it in 10 years?
I really doubt. The older LMP1 class was much faster than the actual LMh around the track. To be precise, the Toyota GR010 is almost 8,5s slower around Bahrain gp circuit compared to the TS050. So is fair to say that, even with fully unlocked specs, the LMh/LMDh cars cannot compete against the older LMP1, even if the overall power output could be matched, the older chassis was much more sophisticated, and so were the hybrid system and aero package.
This strikes me as being the equivalent to putting in an entirely new engine which would be against the rules. If this was a problem they had had previously and knew about it then perhaps it was arrogance that overruled common sense.
The firing order has nothing to do with smoothness i.e. lack of vibration, and all to do with secondary moment vibration which is created be the different displacement profiles of the cylinders when going up vs down. For a flat plane crank these secondary vibrates are present due the pistons being 180 deg apart, however the cross plane is 90 deg apart so the seconday moments are canceled out thus making it smoother. Whilst cross plane doesnt have secondary vibrations like a flat plane, it is heavier so cant rev/accelerate as fast, and its firing order give odd firing on each bank which results in uneven exhaust scavaging so not all cylinders perfrom as well i.e. some cylinders will have higher volumetric efficiency than others, which means less torque & power than a flatplane crank for the same engine.
That's really a surprise. I am not aware of, I would have to check, European engines that are cross plain. I like flat plane because they are simple and work well for high RPM. But as an American, I also like the torque created with cross plane designs. Good luck too Porche if the change is allowed.
@@syntropy3020 Are you sure? Also, inertia is a result of weight. Flat plane crankshafts typically have reduced counterweights. Less weight. They don't really need them like a cross plane does. I would have to recheck which vibrations are which. With a flat plane, imagine a line and there is a crank pin for a rod on each end. Now imagine there is another line that passes through that creates a cross shape. You dont think that a cylinder that gives leverage every 90 degrees is not going to create more torque compared to a cylinder that fires every 180 degrees? I suppose it could depend on your logic as they are both V8s, there is actually a cylinder that fires every 45 degrees, but where those cylinders are in relation to the crank does matter for torque.
@@robertmoore119 yes I'm sure. The reason a crankshaft has counter weights is to counter the primary vibration i.e. the direction of the piston. A flat plane crank doesn't need any where near as much since it's pistons on each 4 cylinder bank are 180 deg apart so the primary vibration cancels within each bank. What it doesn't cancel is the secondary vibration which is cause by the different displacement profiles pistons have as they go up vs as they go down. Cross plane cranks cancel secondary vibration by having the pistons on each 4 cylinder bank 90 deg apart so the net difference in 2nd rate of change i.e. acceleration, of the cylinders going up and down is neutral for each 4 cylinder bank. Both flat and cross plane v8's have a cylinder fire every 720deg/8 = 90 deg, the only difference is the order it happens in which makes no difference to vibration directly, but does make a difference to exhaust scavenging when each 4 cylinder bank has it's exhaust runners joined. Flat plane have even pulsing on each 4 cylinder so if each exhaust runner is the same length then all cylinders will have the same scavaging across all rpm and thus each cylinder will have the same volumetric efficiency across all rpm. This results in a more peaky torque curve at the peak torque will be at the rpm that resonance occurs in the exhaust runner. Typically for performance/race engines this is at high rpm resulting in less torque down low, but it doesn't have to be. For a cross plane crank each 4 cylinder bank has odd firing resuling in different in uneven pulses so each cylinder has different scavaging at all rpm regardless of if the exhaust runners are equal length or not. This results in a flatter torque curve since each cylinder will have a peak volumetric efficiency at different rpm. So in general a flat plane crank will always performed better at the desired tuned rpm, and cross plane makes a sacrifice to give a flatter torque curve across all rpm. This is why flat planes are typically chosen for race applications. Also since flat planes have the same volumetric efficiency on all cylinders it gives a smoother torque at any rpm, where as the cross plane will give different force pulses from each cylinder, but this is pretty insignificant in the scheme of things.
@@robertmoore119 Torque is just a matter of trapping efficiency, peak trapping efficiency for a single combustion happens slightly after peak torque (due to friction loss that increase with rpm). If there's a design flaw/limitation in the intake or exhaust that reduces trapping efficiency due to firing order then it could make a difference between the two crank designs, but not otherwise. 🙂
All this makes me seriously question why they didn't change the engine this way before homologating the car. If they had this issue before on the similarly complex and sophisticated turbocharged 919. Seems like a waste of the "development joker" in hindsight.
Just hope they can change it in time for the 6H of São Paulo, so that I can hear a crossplane 963 irl. Think itll sound much better, I personally prefer a rumbly american sounding crossplane V8
So, this also applies to Ferrari's 499P (a Dallara dressed as a Ferrari)? Besides, the 963's chassis is built with Multimatic (the sponsorship on the tail of the Penske cars explicitly showed their name below the wing).
the fault is on the stupid restrictions! heavy batteries, lame hybrid ev soulles garbage, tiny engines and mfkin flatplane crankshafts! i hate flatplane engines, i just want a reliable fast prototype racecar as i want a fast, fun and great sounding streetcar. big 5.5l, 6.2l. 7l or more cui rumbling v8 and not a crappy 2l v4 or i4 with a heavy electro vacuumcleaner. porsche v8 or corvette v8 or ford gt v8 or amg v8 are the best engines. and they can make tons of power! no need for cucked hybrid crap! if we would build lmp1 or other fast cars like we used to with 2024 tech, we could beat the 919 or 956 bellof records! we just need to get rid of stupid politicking ruining our fun!
Something tells me you're quite misinformed on hybrid race cars: they can actually sound good if you give them the proper engine (I mean, look at Cadillac's V-Series.R or apr's Toyota Prius racer in Japan's Super GT series back in the 2010's). Oh, and about going faster, there's gonna be expenses - LMP1 died partly because of it.
You're channel is so damn good, very under-rated. I wish you more success in this new year.
Thanks a lot!
is the new Kshaft already in the Daytone 963?@@BSport320
It's it a greddy crank saft?
24h Daytona Winner! What a finish!
I just stumbled across your channel and this is probably the cleanest descriptions of car tech I’ve seen. Thank you!
Glad you liked it!
Excellent video ! The truth is that I don't understand why it worked with the Porsche RS spyder and why it doesn't work with the 963, it is supposed to be very sophisticated, obviously adding the turbos added to the electrical part that must be much more delicate is causing serious problems. vibrations to those of Porsche, because this is a very big change for an engine. It's almost like designing a new engine.
Bigger displacement. Simply that adds more vibrations.
not rly
just change the firing order
camshaft(4)
and crankshaft
the rest is the same
if it's a change to the hot V or cold V
then that's when u start basically designing a new engine
Excellent and extremely informative content. You have a great way of explaining concepts without “talking down” to the viewer. Thank you very much!
This subject has been debated for years on motorcycles because its about power pulses and wheel coasting. The tyres need time to slip and grip between power pulses to pull out of corners faster with less tyre wear. Yamaha knows whats up if you look at their cranks. Thanking this channel for great engineering reviews, good work guys.
Yamaha USED to know, just look since 2016-17 Rossi complaining about having no traction and the wheels just spinning while having the LEAST powerful bike in MOTO GP.
@@Random63R400 While it's true that Yamaha has been underperforming, it is worth mentioning that practically every other manufacturer switched to an uneven firing V4.
@@yummyhershey5902 Because you can make more power and they don't have traction issues like Yamaha does (even Suzuki with their inline 4 had more power and control), so the crossplane concept found it's limit or something else cause they aren't the best anymore.
On motorcycles it was about tyre performance. This here is about avoiding vibrations that cause issues in endurance racing.
Great technical insight as always. Many thanks sir. G.
I like the idea. Hope they succeed. But I wonder if they could also decrease the engine stroke a bit, reducing the piston's speed and allowing it to run more smoothly and rev higher AND faster. Sure, they'd lose some displacement, therefore power and torque, potentially, but they could compensate that with more boost or extra power from the electric motors.
I don't think they're allowed to use the electric motors like that. Their use is very restricted.
Can't do it with electric motor since in lmdh that's a spec part which produces a set power
@@scordatura9259 @wiegraf9009 Had forgotten about that. 🤦♂️ Then more boost it is, but this could add more thermal stress to the engine.
They could reduce the stroke and increase bore size
@@dylanhaili5646 Yeah, but considering it runs under boost, it's best to keep the bore stock. A larger bore would mean thinner cylinder walls, potentially compromising the block's structural integrity.
Great video as per usual, as a mechanical engineering student in Ireland, having studied for a semester in Darmstadt, DE, your videos are very informative and insightful
Thanks for sharing
I actually heard the Porsche yesterday and it sounded like a cross plane. Cadillac figured that out last year since the engine is attached solidly. The vet has a softer sprung engine so it can use a flat plane. And yes, 180deg headers can change the sound but it doesn’t solve the vibration problem and adds weight. Example: GT40s ---> TMYK.
what are you talking about? Cadillic has never run a flat-plane crank and have aways run a cross-plane and it wasn't until the C8.r that any GM brand entertained a flat-plane crank. They didn't just figure anything out as these issues have been common knowledge for half a century now.
GT40 is a crossplane crankshaft.
@@ExileXCross More like a whole century!
Missed you! This content is so awesome and appreciated!
Do a video on the 919 and the issues it had
I dont care about the issues it had. I care about the fact it was 10 years ago. Schumis Ferraris are 10 years old in my head, not the 919
One would think that after 100 years of expertise on V engines we would have vibrations mastered...
F1 uses the most vibration prone engine combination possible. 90 degree V6.
@@rolandotillit2867 I dont think the 90 degree bank angle used by teams because its the most vibration prone engine. It is chosen as it is dictated by the technical rule set. Otherwise any angle other than 120 degrees is either a well thought out compromise (eg. for aero gains and other space constraints) at best and poor design at worst.
With all that mass rotating at the speed of sound, you’ll never fully solve it.
@@4rdF1Hunny Mean piston velocity in F1 ~50 m/s @ 12k rpm. That crank needs to go 6x faster (72k rpm) to go supersonic.
@@rolandotillit2867 It was only a bit of an exaggeration.
They could bring it but how will that affect their BoP?
Interesting twist there, as the top street versions of Corvette and Mustang recently have been changed in the opposite direction - from cross- to flatplane 😮
But the engine isnt a structural part there, so the vibrations can be mittigated with the mounts.
They'll have to allow it, otherwise Porsche are likely to pull out. Most series have reliability fix clauses, but they are generally to fix the components that are breaking, not so much a normally functioning component breaking other's, so it's an interesting question!
I hope Porsche will be allowed to switch to a crossplane. They could still use a hot v and route the exhaust gases in a way that the two turbos are evenly loaded with the exhaust pulses despite being a crossplane; BMW did that in a very elegant manner with its hot v street car v8s more than 10 years ago.
So you're saying that Porsche solved the vibration problem with *FREEDOM*.
I think it worked lol
RAAAAAH CROSSPLANE NUMBER 1 🇺🇸
china number 1
Well good luck to them!
You could say they fixed the vibration issue ;)
I hope this does happen. I want to hear what it'll sound like.
Porsche and Audi race teams are so good at problem solving
I have a thought about the V4 they use on 919. What if they reduced the displacement to 1 liter and used its design to help Yamaha or maybe Aprillia. Though gearbox will be an issue, I think they can pull it of
Hell yeah more crossplanes
I dont like the idea, but i understand it was the most efficient way to solve this problem.
It`s very funny when one people say that flat crank is better, others say cross is better. It`s like agrue between left or right sticks of "twix"
How did Porsche overcome vibration problem with V4 engine?
In the video he says they changed the crankshaft to lessen the vibrations. I do wish we knew what those changes were.
@@yummyhershey5902 I don't think it's possible with the help of only a crankshaft. For example my Zaporozhets have V4 engine with balancer shaft
A video about the history of the 919 engine is on my list
Wow, the world is coming around to cross plain being the superior configuration, you could almost say the American muscle cars had it right the whole time.
Wait crossplane? The ones that american muscle cars use?
Yep, thats the one.
So they had this problem with the 919 Flat four during early testing, and again the same thing ? i know it's hard to predict if a design will generate vibrations, given the fact they all test theire engine in single piston design (so no harmonics), but it's 2024... Honda had the same issue in 2017 in F1.
Someone please explain why this crankshaft change to crossplane WOULD NOT be approved? Porsche isn't increasing displacement, just changing firing order for smoother operation at higher RPMs. Always thought crossplane sounded better anyway, see the Yamaha R1...
It most likely will. ACO is very lenient when it comes to safety or reliability related changes so it’s more than likely they will be able to do this without using one of their evo upgrades.
I don’t recall how the upgrades work in LMDh. Are they only permitted reliability upgrades or do they have a certain amount of “jokers” over the duration of the regulations?
They have "joker" for performance related updates
Will the 963 ever be allowed to challenge the 919 Lap record on the Nürburgring? Any thoughts on this? Naturally only once it's not in the racing business that is. They could also go off and do anything needed to beat that incredible record held.
It wont even be able to come close to it
@@Explosivo93 Correct. It has nowhere near enough power.
@@Explosivo93 Time will tell. The 919 was totally unconstricted and prepped for the Ring. Had over 1100 hp afaik. This could be achieved with the 963 if they will do to it what they did with the 919. But who would drive it in 10 years?
I really doubt. The older LMP1 class was much faster than the actual LMh around the track. To be precise, the Toyota GR010 is almost 8,5s slower around Bahrain gp circuit compared to the TS050. So is fair to say that, even with fully unlocked specs, the LMh/LMDh cars cannot compete against the older LMP1, even if the overall power output could be matched, the older chassis was much more sophisticated, and so were the hybrid system and aero package.
@@jamarcus_OG you have some very sound arguments.
They won 24hr of Daytona
This strikes me as being the equivalent to putting in an entirely new engine which would be against the rules. If this was a problem they had had previously and knew about it then perhaps it was arrogance that overruled common sense.
They just want the Cadillac fans attention 🤫
The firing order has nothing to do with smoothness i.e. lack of vibration, and all to do with secondary moment vibration which is created be the different displacement profiles of the cylinders when going up vs down. For a flat plane crank these secondary vibrates are present due the pistons being 180 deg apart, however the cross plane is 90 deg apart so the seconday moments are canceled out thus making it smoother.
Whilst cross plane doesnt have secondary vibrations like a flat plane, it is heavier so cant rev/accelerate as fast, and its firing order give odd firing on each bank which results in uneven exhaust scavaging so not all cylinders perfrom as well i.e. some cylinders will have higher volumetric efficiency than others, which means less torque & power than a flatplane crank for the same engine.
Atleast the Reliability is improved
That's really a surprise. I am not aware of, I would have to check, European engines that are cross plain.
I like flat plane because they are simple and work well for high RPM.
But as an American, I also like the torque created with cross plane designs.
Good luck too Porche if the change is allowed.
Most European V8s in street cars are cross plane.
Cross plane doesn't increase torque. It just reduces secondary vibrations at the concequence of higher intertia and reduces exhaust scavaging.
@@syntropy3020 Are you sure? Also, inertia is a result of weight. Flat plane crankshafts typically have reduced counterweights. Less weight. They don't really need them like a cross plane does. I would have to recheck which vibrations are which. With a flat plane, imagine a line and there is a crank pin for a rod on each end. Now imagine there is another line that passes through that creates a cross shape. You dont think that a cylinder that gives leverage every 90 degrees is not going to create more torque compared to a cylinder that fires every 180 degrees?
I suppose it could depend on your logic as they are both V8s, there is actually a cylinder that fires every 45 degrees, but where those cylinders are in relation to the crank does matter for torque.
@@robertmoore119 yes I'm sure. The reason a crankshaft has counter weights is to counter the primary vibration i.e. the direction of the piston. A flat plane crank doesn't need any where near as much since it's pistons on each 4 cylinder bank are 180 deg apart so the primary vibration cancels within each bank. What it doesn't cancel is the secondary vibration which is cause by the different displacement profiles pistons have as they go up vs as they go down. Cross plane cranks cancel secondary vibration by having the pistons on each 4 cylinder bank 90 deg apart so the net difference in 2nd rate of change i.e. acceleration, of the cylinders going up and down is neutral for each 4 cylinder bank.
Both flat and cross plane v8's have a cylinder fire every 720deg/8 = 90 deg, the only difference is the order it happens in which makes no difference to vibration directly, but does make a difference to exhaust scavenging when each 4 cylinder bank has it's exhaust runners joined. Flat plane have even pulsing on each 4 cylinder so if each exhaust runner is the same length then all cylinders will have the same scavaging across all rpm and thus each cylinder will have the same volumetric efficiency across all rpm. This results in a more peaky torque curve at the peak torque will be at the rpm that resonance occurs in the exhaust runner. Typically for performance/race engines this is at high rpm resulting in less torque down low, but it doesn't have to be.
For a cross plane crank each 4 cylinder bank has odd firing resuling in different in uneven pulses so each cylinder has different scavaging at all rpm regardless of if the exhaust runners are equal length or not. This results in a flatter torque curve since each cylinder will have a peak volumetric efficiency at different rpm.
So in general a flat plane crank will always performed better at the desired tuned rpm, and cross plane makes a sacrifice to give a flatter torque curve across all rpm. This is why flat planes are typically chosen for race applications. Also since flat planes have the same volumetric efficiency on all cylinders it gives a smoother torque at any rpm, where as the cross plane will give different force pulses from each cylinder, but this is pretty insignificant in the scheme of things.
@@robertmoore119 Torque is just a matter of trapping efficiency, peak trapping efficiency for a single combustion happens slightly after peak torque (due to friction loss that increase with rpm). If there's a design flaw/limitation in the intake or exhaust that reduces trapping efficiency due to firing order then it could make a difference between the two crank designs, but not otherwise. 🙂
Porsche’s expertise is boxer engine, so why go V style.
Porsche's last Le Mans wins were done using the Vee configuration when they raced the 919 Hybrid.
All this makes me seriously question why they didn't change the engine this way before homologating the car. If they had this issue before on the similarly complex and sophisticated turbocharged 919. Seems like a waste of the "development joker" in hindsight.
Just hope they can change it in time for the 6H of São Paulo, so that I can hear a crossplane 963 irl. Think itll sound much better, I personally prefer a rumbly american sounding crossplane V8
Still turbocharged but yeah
@@wiegraf9009 yeah, it still sounds good imo, the second best sounding LMH/LMDh imo, behind the Chadillac of course
Its NOT a Porsche, its a Dallara dressed up as a 'Porsche' Sorry.
So, this also applies to Ferrari's 499P (a Dallara dressed as a Ferrari)?
Besides, the 963's chassis is built with Multimatic (the sponsorship on the tail of the Penske cars explicitly showed their name below the wing).
slowlier, smoofer, with 2 crank shafts.
the fault is on the stupid restrictions!
heavy batteries, lame hybrid ev soulles garbage, tiny engines and mfkin flatplane crankshafts!
i hate flatplane engines, i just want a reliable fast prototype racecar as i want a fast, fun and great sounding streetcar.
big 5.5l, 6.2l. 7l or more cui rumbling v8 and not a crappy 2l v4 or i4 with a heavy electro vacuumcleaner.
porsche v8 or corvette v8 or ford gt v8 or amg v8 are the best engines.
and they can make tons of power!
no need for cucked hybrid crap!
if we would build lmp1 or other fast cars like we used to with 2024 tech, we could beat the 919 or 956 bellof records!
we just need to get rid of stupid politicking ruining our fun!
Something tells me you're quite misinformed on hybrid race cars: they can actually sound good if you give them the proper engine (I mean, look at Cadillac's V-Series.R or apr's Toyota Prius racer in Japan's Super GT series back in the 2010's).
Oh, and about going faster, there's gonna be expenses - LMP1 died partly because of it.