How Lancia Reinvented A Twin-Turbo Four-Cylinder
2024 ж. 26 Сәу.
118 445 Рет қаралды
- Patreon -
/ visioracer
- Timestamps -
00:00 Intro
01:03 The beginning of turbos
01:27 Racing Lancias
02:13 1,000hp Delta S4 engine
03:35 The canceled Group S
04:28 Experimental Composite Vehicle
05:11 Lombardi’s trickery
05:51 The genius technology
07:24 BMW’s Triflux engine
07:48 The ECV still lives
- Disclaimer -
This video is fair use under U.S. copyright law because it is transformative in nature, uses no more of the original than necessary and has no adverse effect on the market for the original work.
Hey guys, you love these videos and to ensure that you will still have the opportunity to watch new videos, considering your support also through Patreon: www.patreon.com/visioracer
This should be the second part of the Fiat TwinCam engine, i am still waiting for that video VisioRacer. 'Til that moment take a like and added to favorites.
R.I.P. Beppe Volta
Best ever
This should be brought back, and used in a diesel. The extra swirl would do amazing things to keep smog low, while still getting great power. Many 4V diesels have port restrictors to generate swirl, this system could get as much or more swirl, while having more port flow. That would get more power with less weight and less turbo lag.
You’re totally correct. Would work great in a diesel application. It’s too bad manufacturers are obsessed with EVs now. They’re not going to waste time with the development of new diesel technology. Since the VW diesel-gate scandal, diesel cars are being seen as dirty and bad for the environment (even though that is not the case). I wish we could go back to the days when most cars weighed 3,000 pounds or less and got 40mpg without any complex smog and emissions crap. Make the driving tests harder so idiots can’t drive. It will lower the number of car accidents which means cars won’t need as much crash protection. Less crash protection reduces weight and improves economy and performance.
@@portermcsorley Yeah, VW screwed us by faking NOx readings on their non-DEF engines. If VW didn't do that, they wouldn't have screwed up so many diesel sales in the USA. I considered buying a diesel Jetta. I am so glad I didn't, I would be burning with road rage, knowing I would have had a car that was a fraud. VW eventually put DEF in the Jetta and Golf, but then they were exposed for their 2009-2013 variants committing fraud. The Passat always had DEF and didn't have that problem, I think.
@@portermcsorley can't and won't ever agree on less crash protection. No matter how well you drive, people around you won't necessarily be the same, even with proper driving tests. Accidents will always happen and I don't really wanna die or kill my family because my car is just unsafe and some freak accident happened to get me involved. Plain oil on the road in a rainy day could kill a family if cars had less passive crash protection, and that's entirely out of one's control. It is true of course that making them lighter will improve fuel economy, it just might be quite costly keeping the same standards.
There is at least a single diesel that uses a similar technology of the centre intake ports, the BMW M57 if I recall correctly
@VisioRacer and you would be correct.
I'm always blown away Visio Racers content. That engine is amazing, rally engines are so innovative.
Thank you!
Beppe Volta, a true LEGEND. Without him, the ECV would be just a forgotten page in motorsport🙏🙏🇮🇹🇮🇹
I was always fascinated by this engine. It seems to tick all the boxes of being thermally efficient. Yet no one seems to have made it to production. Still wonder why is it so.
Because sometimes what seems good in theory either doesn’t really work any better, or isn’t worth all the trouble. With this I imagine other technologies, like turbos, got better so all the extra complexity wasn’t worth the performance gains.
Cost, mostly. A single turbo on a 4 cylinder engine is good enough for most use cases, especially since turbo tech has evolved greatly since the mid 80s. Additionally, it is very space inefficient, making packaging it into a car difficult.
its the costs
Others have already mentioned cost: you need two turbos, two waste gates, two exhaust manifolds, two intercoolers, two blow-off valves, and so on. Add to that the utter nightmare of trying to package this in a normal road-going consumer car. The special intake plenum just towers straight up from the engine block and the block also needs lots of space on both sides. No problem for a race car, but commercial production cars play by quite different rules.
With the improvement in turbocharger design, engine management etc it's not needed, for a production car there are serious issues with packaging and cost.
I'm not a mechanical engineer and I don't have any academic background in the field. But I'm enthusiastic about the subject and some time ago I even drafted a system very similar to this one from Lancia, but it was for a flatplane V8. It's very interesting to know that someone in the past thought of something similar, and the best part is that it's functional and not just a crazy idea from a random person.
Finally, someone who pronounces Lancia correctly.
I was always taught to pronounce it as "Lan-chi-ah", but I am a Slovak, we pronounce every single letter in every word 😆
@@VisioRacer You pronounced that exactly right: Lanča. It really bothers me when someone says they are a fan of that brand and then can’t even pronounce it right. BTW: love your channel.
@@stephmaccormick3195 Thanks, Steph!
For the passionate, Eng. Claudio Lombardi (S4 engine and Delta serie) has recently worked on the remake of the Lancia 037, namely Kimera EVO37.
That is quite a concept! The crossflow looks like it would work well. Stratos is the coolest car ever built.
1 - Never seen that before! So happy to see it + explained so well! 2 - WHOA! four-valves-per-cylinder BUT Middle-out, rather than one-side-to-the-other! 3 - DOUBLE-WHOA! Apparently-twin turbos WORKING AS IF THEY ARE SEQUENTIAL! 4 - 6:13 - wATCHING THE REST OF THE vID... How many more 'Whoas' can there be??? (BRB) 6:52 - I've given up being surprised... Bravo Lancia..!
NO...!...NO..!....!!!.......Bravo FIAT........!!!! that marvelous engine technology is FIAT !!!!.......Technology..!!!!
I built a model of this car back in the 80's.That intake set-up blew my mind.
Wow that BMW engine is sick aswel, really cool that tou mentioned that one!
I was thinking “what about the M10?!?!” as you described the Lancia cross flow head and then … you brought it up to give credit to a design that proceeded Lombardi’s concept by 20 years. Superb work, thank you.
Exactly, whenever i see this kind of head design i'm immediatly thinking "Apfelbeck". XD
Dude I love your content. I have watched you for many many years and you tought me so much about engine technology and what people do with different engine to get different effects. I have watched you for probably 10 years or so and became an engineer because I love to learn about mechanical systems. You're awesome man.
This is very pleasing to hear, Josh! Thank you! I have been doing KZhead since 2015 so it is cool to hear that you've been watching it all that time
Tri-Flux head is a patent of FIAT. This head with a twin Turbo or Turbo plus a supercharger configuration is amazing. Can't understand why it didn't evolve beside costs, piping, etc.. 16 valve DOHC , 1.6, 1.8 Liters can reach tremendous amount of power, and stay cool. Impressive configurations from my youth.
I fricking love this video, keep up man! One day i will be one your patreons 🎉
The company entered rally with the fulvia first but you got close enough. Great vid none the less
Yeaaaah, sorryyyy
@@VisioRacer great video man, very educational!
Excellent video. Thank you. Always learning. Cheers from NZ🇳🇿.
Thanks, Michael!
Great video. Fiat is a very underrated engine producer.
Exept the Fulvia,s and Stratos..........All 4 cylinder engines used by Lancia in rallying .....were FIAT ....engines.....the Intergrale ...and ....Delta S4 ...engines are FIAT ...engines ..!!!!!!! FIAT automotive engineering technology is second to NOBODY....!!!!!!!,,,GOAT..!!!
This video is really amazing and I apreciated it a lot, please do a video on the Lampredi engine too.
Thank you!
@@VisioRacer I watch you from quite some time and your videos are always done with great quality. Please consider the idea of the video on Lampredi.
Great video, brilliant research to make a fascinating production. Well done and keep up the good work!!
Thank you, Ben!
It's a good Saturday morning when I see VisioRacer upload
its already early sunday here... 🐱👍🏿
It's early evening here in central Europe
Should note Lancia started rally racing with the Flavia and Fulvia, as well as the Beta Coupe before the Stratos.
I thought of this in highschool. Thought it was revolutionary. Glad to know 15 years later it was already done 30 years ago ..learn something new everyday.
That Lancia engine sounds so uniquely pissed off! Like it's pissed, it just wants to destroy air and fuel!
I'm so glad this guy is still making content. I remember like 5-6 years ago when he first started out. Still making insanely entertaining content to this day.
That guy is very pleased with such a comment.
Nice video, today you also nailed the italian pronunciations!
Oh, wow, thanks!
Packaging is probably the biggest issue with this. The intake design makes for a much taller engine. Not such an issue for a mid-engined car but for a front-engined car the hood would have to be quite tall, even with the engine leaned over at an angle.
VW has already done it with the 1.4 TSI (Twin Charged, Turbo and Supercharged)
Very interesting. Thanks for sharing.
Great video!
Thank you so much for this content! This engine was supposed to run in the Monte Carlo Group 5 Silhouette but never did. Apparently Volta has 5 or 6 engines sitting on shelves collecting dust although that might just be a rumor.
I think that Beppe Volta bought a whole bunch of engine parts and leftovers from factory, when they shot down the racing department in Lancia! So it all sits somewhere..
That trifle head is awesome, imagine a modern LS or LT engine with heads like This, with about 6.3--6.6L a 6.3L two versions, one for light truck, and one for cars, the car version having 3.375" stroke, and 4.25" bore, the truck version having 3.80" stroke and 4" bore, both being near equal displacement, with the truck possibly making much more low end TQ, the performance "car" version designed for more high rpm HP, revving about 1500-2k RPM higher, 8500 rpm redline, direct injection, quad turbo, and naturally inspired power, the center exhaust crossing the valley and exiting behind the head and down, or in front ina similar exit , using a oval pipe about 1.25" x 1.5" with a cast steel header with 1.5" internal ports, with wall thick enough to open it up to 1.7" or 1.8" non turbo, without modification, (welding the exterior,). With a rocker system allowing pushrod cam in the valley, with roller lifters, and direct injection , dual pumps, dual injectors, a in valley set, as well as a outer set, the intake vales divided one on one side one on the other, should increase swirl a ton, especially if the port has any features to induce swirl, possibly add a feature to introduce tumble as well, a pair of 1.5" exhaust valves. And 1.7" - 1.8" intake should be fitting, with long 6mm stems, conical springs, the truck version should be capable of near 600 HP, at 6250-6500, and the other should be capable of near 750 at 8200, natural HP, and 1000hp, and 1600 HP with 15-16 psi boost, definitely use a cast steel block, with wet liners, 6 bolt. Mains, 4340 crank and rods, 6.250'' rods coated forged Pistons with 10:1-11:1with boost, , and 12.5-13.5:1 without boost, and use additional fuel injectors at mid runner, to chill the air, e85-E100 recommended, 3 injector per cylinder should supply enough fuel!! A C8 Vette would be a fitting engine for that, as well as a Camaro or a modern version of the GTO from the 2000's maybe a modern 70 z28/ss Camaro, it would be awesome, the split bumper can look how designers intended it!! That grill with no bumper disturbing the looks, and modern LED lighting, with tail lights made up of LED rings , inside of rings, with a single 3-5 watt led in the center, with a 5-10 watt white led in the center of the outer, or inner pair of round tail lights, with the headlights similar, with a 50 watt projector led and 20 watt DRL plus a 5-10 watt halo, white and amber, with turn signals with halo in side halo, with the outer , the moving inward to the center for each flash with just like the tail lights, with the outer ring for running lights and the center as well as all rings lit for brake lights, with a high mount center brake light made of 3rows of LEDs, that grow from the center out when the brakes are hit then flash, alot like a bulls eye. 🎯 Only flat, it would be a cool car, also offer a 4cylinder turbo version, with a 25kw electric motor connected to the rear diff, with a 100 mile range, a basically k24 turbo, with 6speed manual, or 8 speed automatic, only a larger engine, 2.6L maybe a 5 cylinder 3.0L , and using the electric motor with the engine , it should be qual to a 650 HP engine, the maybe use the triflow making an additional 250 with boost!! Sorry to ramble!!
Just imagine that tri-flux design on an I-6 with four turbos..
i don't want to imagine, 4strokes are pretty efficient with a turbine each three cyls. so two turbines for I6 is really good. 4 cyls is not divisible by 3 as can tell. so they have to invent stuff to accomodate, like double ports. but never is as good as a simple turbine with 3 cyls.
@@Xayuap But you would have 3 cyls feeding two turbines. Smaller turbines, less lag, more boost with better flow/efficiency. Adding to that the 6-cyl duty cycle and balace by design.. It could make a solid 1000+ hp from 3200 to 17500 RPM
@@oikkuoek you don't need that because exhaust pulses don't overlap for three 4strokes cyls. Just one turbo each cyl would do. Ask to the RB26DETT
@@Xayuap I personally don't need any of that, but it would still work better than just having two valves per side opening simultaneously. You can feed one big single with an I-6 up to four digits, but having four, or six as compound 3 per side, with the added swirl and better overall runner design, it would make heaps more power. I-6's choking points are the runner openings in the head. Even though the valves would flow, the opening and the valley between the opening and the valves disrupts the flow, on both sides. Tri-flux design overcomes that turbulence completely, filling and flushing the combustion chamber significantly more efficiently than conventional 4-valve cross-flow head design. And the mentioned heat distribution would benefit I-6 even more than I-4, and the power stroke overlap on I-6 would require less stroke, rising the redline easily to 5 digit range. (Honda CBX)
well, maybe three turbs with dat tech
Really cool to see how the engine worked with those shots you found of the cylinder head. And also very cool to hear some of the other engines you talked about! Am I wrong in thinking Lancia got back into Rallying with the Fulvia before the Stratos though?
Thank you for this! Excellent work as usual.
I appreciate it very much, thanks!
The turbos weren't shut down, they were different sizes, a smaller one that would spin up and give good boost at lower RPM and gas flows, and at higher RPM/power level the second would provide the additional air as it had spun up by then.
That 222d is beautiful
An effect of the diagonally opposed valve pairs is that each camshaft runs both intake and exhaust valves, so the cam phase control techniques used now would not work.
that's amazing
I see Visio and Lancia. I click. I am happy.
That makes me happy too!
Very straight intake port with just enough bend to mitigate valve shrouding, vortex in the cylinder due to the valve configuration, excellent thermal characteristics... What a design. The plumbing is extremely complex though.
Very cool
Great Content, as always. I loved the Stratos, but always thought the S4 / Delta / Integrale were always butt ugly, and never appreciated the engineering behind these not-so-pretty, but damn fast cars.
you are not the only one.......people that knew nothing about cars .......always had a lot to shoot their mouths off ......but all these World rally Championship Lancia,s......the ,,...S4 Delta included.....all 4 cylinder motors were FIAT MOTORS ....Hard to believe hey ...???.......all this "' ugliness "' you saw ...was design orientated....and it worked ....that is why LANCIA is the most successful rally marque.....ever....( Although with help from their brother...FIAT ...!!!)
The world is a lesser place without the bonkersness of the lunatics at Lancia. 😔
I really love sound turbo and supercharger on one engine this setup needs be in modern cars.
6:56 how camshaft work?
Lancia made the Delta S4 silhouette body of ultra thin carbon fibre, chassis of bike frame tubing and an aluminium roll cage ! I'm really glad Group B was banned before more drivers died !!
What engine is it twards the beginning? It has such a scazy small stroke!
Amazing video! I always loved the lancia s4
Ever heard of an 80s oldsmobile 4 cylinder with double exhaust?
I showed this video to my 1974 Fiat 124 Spider. She was so proud, she leaked a little!
With Apfelbeck design you can put bigger valves on a small bored engine, but when the flows comes into the combustion chamber, they are face to face?
The question is whether, today, this double supercharging of the engine is cost-effective for manufacturers. Volkswagen has already demonstrated with its 2006 Golf V 1.4 TSI 170cv GT Sport DSG 170CV that it was not. It only lasted 2 years on the market. There have been today, for quite a few years now, more efficient solutions to find engine torque and power at low revolutions in turbo engines such as the "twin scroll" or variable geometry for diesel engines (205 T 16 E2 had a similar system) or the "bang bang" anti-lag in rallies. Although Lancia's idea was good, at that time there was not enough advanced electronics to manage the combination of the Turbo and the Volumex and the power delivery was too abrupt and driving the car was quite complicated (said by Alén and Biasion, I'm not making this up).
Just a couple mistakes : the S4 engine is not a Fiat block : the 90 mm bore spacing of the Lampredi iron block (that was used in the 037) would be insufficient for the 88.5 mm bore and the extreme pressures. And , only the road version had an open front differential : the racing one had an LSD that could lock up to 40% (in the rear , it was 60%). And , the Group S never had a 300 hp limit : that was the Group A!
The S4 engine was a completly redesigned block by FIAT ......Lancia belongs to FIAT ..and they use all FIAT engines ...parts ...components etc ..etc...Where did you think Lancia got that engine ????......China ...???lol.
@@kingalfred3902 No need to say that. I already know. Point is : it's not the same block , it's not the same engine. The ATR18S is not a Lampredi.
@@giuseppec8158 Nobody said that the S4 Engine was a Lampredi ...!!!.....The S4 engine was still a Fiat designed engine ..!....The triflux head was FIAT ...designed..........The only non Fiat engined....... Lancia,s.......was the Fulvia,s ...and Stratos ....ALL other Lancia,s used FIAT engines .!!.....Some .people just hate it when FIAT achieves success ...dont they ...?........they cannot accept the fact that the so called ..."'.unreliable ''...FIATs are world beaters .!!!
If l recall correctly the Russians had an inline V-12 aeroengine with intake valves and exhaust valves with one of each inboard and outboard in each cylinder. Unfortunately i cannot find the website right now.
Kimlov M-105 and VK-107. They actually had an even stranger layout, the valves are rotated 45 degrees from normal. For each cylinder, on the inside of the V there is just one exhaust port. On the outside, an exhaust, a normal inlet port coming from a blow through carb (total of 6 carbs on the engine, they are shared between cylinder pairs) and a port that takes uncarburretted air direct from the blower. The exhaust from the inner ports was collected by a pair of manifolds that ran forward and exited in front of the outer ports, leading to seven exhaust stubs on each side of the engine.
Pretty sure I'd give up a limb for that Martini Livery ECV...
it's however not howether, besides that great video keep it up
Twin-Turbo 👌
Bro, do a 90degree belt engines please..
It's easy to produce more power , it's harder to do it and meet government fuel economy regulations . A rotary engine is tiny compared to anything that produces the same amount of power as it . But it sucks back fuel like a big block V8 .
The other challenge is making the rotary smog legal and durable.
Same thing with two strokes 🤷😟
You made a little mistake, lacia actually entered rally before the stratos, they entered rally with at least 1 car before it. That car was the fulvia
Yes yes, my bad. Totally forgot about the Fulvia
@@VisioRacer hahah no worries I just wanted to point it out. Nice video though 👍👍
Lancia nel ❤.....
i thought Lancia started rallying with the fulvia? or was that not official lancia racing?
Lancia rallyed with many cars. The Fulvia, Delta, 037, Stratos…
@@VisioRacer exactly….so your video is wrong…
@@tsb3093 It's not the whole video wrong. I just forgot about a single car. And since it is not the core of the video topic, I suppose it is not a big deal. Sorry for the mistake.
@@VisioRacer well at least you have held your hand up and acknowledged the error….
@@tsb3093 No point saying otherwise, you are right
buonasera ma la famosa lancia stratots che montava il 2.4 V6 era di origine Ferrari oppure abarth-martini e volevo sapere se montava anche il twin-turbo!? oppure no!!!!????
old version TSI :)
Nowadays you just slap a twin-scroll turbo on a 4-cylinder with an appropriate set of headers and you're good to go. Spools up quickly and even a small-ish twin-scroll turbo can pump out significant boost at relatively low RPM.
Group B needs to come back.
Lancia was rallying decades before the Stratos.
Vw also using twin charge,in production car,after decades
Imagine if you could do this with an inline 4 with a 20 valve head. Have one valve running a smaller turbo and cam lobes with a VTEC system or with the Free Valve technology on you could really get the small turbo spooled up quickly. Then, have the larger single turbo activated by the dual exhaust valves. Then, on the intake side, a twin screw supercharger or roots style supercharger and a massive intercooler between the head and blower unit. I don't think a centrifugal supercharger would add anything at all to a setup like this the twin turbochargers wouldn't already be accomplishing. Plus with a twin acrew or roots style supercharger it could bet the immediate boost amd then you could have a bypass valve that would open up and progressively bleed off the supercharger boost and have the turbos come in. I would build it with as large of a bore as possible to take advantage of the added area for the biggest valves possible and a short stroke to get the revs to build quickly. I don't know if I would do a 1.8 but a 2.2-2.6L since it wouldn't need to fit in any set of rules I think would be perfect. Run it on Methanol, or E85, with a very high compression, and it would be an absolute riot. But the fact that he was able to do this back in the late 70s or early 80s is what's so mind-bending. There are much easier ways to now make this kind of power but absolutely amazing build and leap forward in technology for the time. Incredible upload as always Visio.
And your point is ....?????
@kingalfred3902 modern turbo, engine control, metallurgy technology, airflow and fuel injection technology would create a completely different beast. Not to mention how much better our fuels are now.
👍💪✌
Those monster car most by 80's group b rally era is truly monster rally car 2.0L line 4 twin cam 16~20value engine + huge big turbo charge making 450~650hp huge terrible horsepower and toques in light weight 750kg~1.1tons rally car making terrible speed But in the past those monster rally car is killer a lot in 80's young famous rally driver, famous rally champion die in that monster rally car ! Only can say is.......... "Too faster and Too furious" ! But nothing or anything can stop rally racer, stop rally champion to chasing speed, power and win to be a rally champion ! About old days in 80's group b rally racing is most all of die-hard rally fans to talking about rally history and memory ! Even those memories some good, some bad, even feel sad ! But nothing can change is most of rally race golden age ! But rally car racing until now feel rally race like kids play video game ! No more old days toughest and roughest challenge ! No more real damn good driving skulls and stunning driver style ! Most by now those new generation rally car look like matchbox mini car ! 1:18 model toys car ! Everything but computer, micro cheap, electric system support rally driver....... I can't imagine by now new generation rally racer, rally driver how to challenge those old day East Africa Safari rally ? Huge rain after rain fall flooding water flooded all race track, after rain how can be passing though sticky and slippery wet mud, afternoon super hot and wet weather making engine overheating and sharply rocks and stones crashing the car chassis and suspension, tyres, wheels even break down gear box and transmission system ! How to survive ? How to passing though all of race and rally stages ? How can be keep car safe and running well and win the race ?
It is a pity you do not elaborate on how they shut of one turbo, this is only possible by an extra butterfly or enabling half of the exhaust valves. Suppose the used a butterfly, but I do not see it in the drawings.
As another viewer (Lee Watson) commented, it probably used differently sized turbochargers, optimized for different engine speeds, rather than actually controlling one of them.
that turbo name 👻💀💀💀
Undoubtedly, cost. Production would be unlikely to recoup due to very high cost of tooling.
what do you mean lancia enter rallying with lancia stratos which is not true? Lancia dominated with the Fulvia in the 60s why do people forget it.
Yes, so did it. My bad ✌🏻
Lancia è stata la Regina dei Rally! Ma purtroppo caduta in disgrazia per colpa della cosidetta "classe dirigente" italiana, che non ha mai avuto ne classe, ne tantomeno dirigenza! Ciao e complimenti da Genova Italia!
Lancia Tri-Flux cylider heads
it's too bad that they discontinued Group B and then not to even bother releasing Group S?? There were so many phenomenal innovations that were created because of this. Now we have the crappy EV vehicles. There is nothing like the combustion engine, turbocharging supercharging, high revving engines, etc...
Lancia did not enter rallying with the Stratos .........LANCIA was rallying long before the Stratos with 1300 and 1600 cc Lancia Fulvia ,s ....in the the European and World rally championships ...!!!!!...i only lisened... a few minutes to your post ....and i stopped ....Where did Lancia re invent the twin turbo ...?????......The Delta S4 has got a .....super and turbocharged Triflux 1756 cc Engine....!!!!!....FACTS my friend FACTS ....!!!!!
5 bar 😬
and that was in 1985 😬
Goes to show lada communism can make a rally car in the golden era with the Samara in the early 90s
Wow what a car brand thats absolutely nowhere today. You couldn't even say its a shadow of its former self, but more accurately its on life support making handbag/purse cars for urbanites. What a fall from the bleeding edge of rally technology, to being a car maker thats laughed at today. Whats the Lancia they make today called: The Lancia Bagina.
Stai parlando di icone italiane,fai il serio,metti i sottotitoli in italiano,quando fai sti video🧑🔧🐺
its not twin turbo its twin charged
The ECV was a twin-turbo
Back when us, as Italians, we were doing things better!!
Only 5 bar and 1000 hp 😂😂😂
I thought Lancia invented it?
lancia was the face of the fuat group in rally because of the sucess they had with the strattos and fulvia before fiat acquistion that already owned abarth
rally cars sure got ugly after the stratos
A turbo and a super is not a twin turbo.
That is a twin-charging. Twin-turbo is simply twin turbos ✌🏻
Too bad they are out of business
I know this head as "Apfelbeck" head. Ludwig Apfelbeck from Austria invented that head in 1937. Here is the link to the German Wiki entry: de.wikipedia.org/wiki/Ludwig_Apfelbeck Apfelbeck worked with BMW, Maico, KTM and Horex. He also invented the ConCam. A camshaft with conical lobes. He wrote two books. These books are a must-read for any 4-stroke tuner. In my eyes, he was a genious. Maybe, you dedicate a video to him. ;-)
Great video!