Sadly, there are fewer and fewer videos on RUclips like this. Originally, we were told that the "information superhighway" was going to be the great educator and a universal source of information. What we now have is a world of clickbait, gambling adverts, trolls and stuff encouraging adults to remain as mental juveniles. So thank you for this video which fulfils the original brief. I spent thirty odd years in motor sport, primarily building competition engines, but have very little experience of super/turbo charging. I've had this on in the background whilst repairing a vacuum cleaner, but I guarantee that I'll be watching it again while not repairing anything so I can concentrate.
😂 Yes, authoritative bright and concise engineering progression being discussed on interesting race cars... Is not the common girl jumping on a trampoline❤
There has always been a plethora of information irrelevant to you. However, you used to have the Luxury of curating your online experience simply through the problem of having to be specific in your searches. Now, due to the advanced Indexing and Content Delivery alogrhythms, you are exposed to a large amount of information which is irrelevant to you. It's a new spin on Plato's Cave.
I got to see and hear an Alfetta 159 on track at Laguna Seca in 1991 in celebration of Il Maestro Juan Manuel Fangio's 80th birthday. What a GLORIOUS sound that 1.5 litre straight eight made. Fantastic.
@@GregsAirplanesandAutomobiles I'm jealous of my old self. I live far from a road course (or even mountains) these days. My first gen Miata misses those roads as much as I do. Seeing and hearing the Alfetta was a rare treat. I got to speak with some of the Alfa folks, and made friends with one of Fangio's mechanics Guido Moroni even though I don't speak much Italian and he didn't speak any English. He saw me around the car so much that weekend, he joked "hey, a million dollars, and we go to Mexico and the car is yours...). Fangio was Pure Class as one may have read. Drove his Mercedes GP car so fast on a demo lap (at 80 years old) the driver of the camera car (in a modern sportscar) spun trying to keep up.
@@williammorris584 Were you there for the hill climb or for the track event (I can't remember which they call each one)? Either way, great sounds. I'd love to hear one of those V16 BRMs with the centrifugal blower in real life, I've only heard them on video. A Colombo derived 3.0 liter V12 is one of the greatest mechanical sounds to my ear; love the Alfas too of course. Cheers!
taking us from piston engines to jet engines, just by following how good multistage-compression is, that a piston engine simply isn't needed anymore? masterful
Jet engines are not very suitable for ground transport in terms of efficiency and turning driven wheels. So the piston engine still has a place and advantages depending on application.
@@AlienLivesMatteron today's vehicles like tanks jet engines are likely to have extra thirst for various fuels. Not a good seller if your car need more than double than a diesel engine.
@@AlienLivesMatter Turbines are great for torque, just look at the military applications in Tanks. The Abrams and the T-80 MBTs are arguably the most formidable tanks ever made and they both run Turbine engines which produce plenty of torque. The problem with Turbine engines in Cars was the fact that Cars have to share space with pedestrians, and that they're nowhere near big enough to displace the heat properly. You ever feel the warmth when standing next to an exhaust? Well ramp that up by about 10 and you'll understand why Turbine cars never caught on.
I saw an old movie that described how the jet was just an existing supercharged engine without the pistons. Which made sense, This discussion really brings home just how close everyone was by the mid 40's to eliminate the piston. THanks!
Mercedes was also running two stage Roots blowers in 1939. Post war Ferdinand Porsche designed and built a rear engined flat twelve cylinder four wheel drive two stage supercharged formula one car for Cisitalia, but it was so complex it led to Cisitalia going bankrupt before it could be raced.
I come here for the straight story. Greg never backs off from a complex subject. He might simplify to suit the explanation, but the raw data is there, and it's backed up with sources and genuine understanding. My hat's off, sir!
I just love the depth of content in your vids. Fell in love with Alpha in the 50's, well before I could drive. Their single minded pursuit of technology, beauty, and performance won me over, and formed my understanding of mechanics and art. When my Italian uncle, who sold used cars, offered me a 1958 Alpha Guilietta Spyder for $400 I was head over heels. Later he would sell me a Fiat 850 Spyder at cost. Neither were fast, but that wasn't the point. I had a brother 7 years younger than me, and I foisted my ideas on him. Later we would build boats together. Still later we would brainstorm carbon fiber bicycles. This Fall my brother, Bob Parlee died due to cancer after 25 years as a renowned builder of carbon fiber bicycles.
Well I've been getting the stages backwards since I first took an interest in two stage supercharging as a teen. So thank you for straightening me out at 74 years old, lol. Andy Granitelli's version of the Novi V8 featured 2 stage centrifugal supercharging and they put out monstrous power at Indianapolis from 62-66. Too much power perhaps because they were treacherous enough in the curves to kill 2 drivers when they only had a single impeller before Granitelli took possession. Drivers were afraid of them because they'd break the tires loose anywhere on the oval track even on straights coming out of the curves. The high speeds at Indianapolis and the larger displacements make the risks even higher. In '63 Jim Hurtubise started the race taking the lead on the straights but giving it up in the curves on just about every lap. When oil got on the track Hurtubise was the first car flagged though his Novi wasn't leaking. I've always suspected that happened because they were concerned about the Novi's reputation for breaking traction. Rookie Bobby Unser also drove for Granitelli and there is a RUclips audio only Video of his qualifying run in a Novi that just screams going past the microphone in the stands. Another driver was Top Fuel quarter mile shoe Art Malone. No Novi ever won the ran despite often qualifying in the front row including pole position. They usually broke or crashed. So I wonder if Granitelli's Novis had an intercooler and If they ran both impellers off the same shaft Merlin style but I wouldn't know where to find that information.
According to "Novi V-8 Indy Cars" by Ludvigsen the Novi's ran with just a single stage compressor. Early Novi's used an intercooler, which was deleted from 1953 on to save weight. Intercooling is generally considered not to be necessary when running alcohol, see the Hoonigan Mustang which reportedly produces 1400 hp with two huge turbochargers and no intercooling.
The way you described turbine engines finally made it click for me. I've heard people call them "sentient turbochargers" before but i guess i've just never made the connection until now. Neat.
It's exactly how I came to the realization when I was younger too. The supercharger gives intake and compression, we know exhaust makes thrust and can deliver power to a shaft via a turbine, and ignition is covered by a plug anyway. That's all four cycles. The piston starts to look like an unnecessary middleman, at least in concept when practical realities aren't a factor.
@@pgtmr2713 This might sound crazy but why not have a large cf paintball tank plumbed to the intake before the compressor. It will really help with spooling the turbo and it will come out at subzero temps so it will help with knock too. There is a drag car that runs on 2 Scuba tanks of normal air at 3000psi. I forgot the exact HP number but it was well north of 1000hp and ran a blistering 1/4 mile. They claimed estimated -20 degree intake temps due to the compressed air cooling down as it drops in pressure.
@@joshuaszeto That is way too extreme. The point is to prove the concept would work. Stored air or nitrous runs out quick unless there's a compressor to refill it with air. I believe there was a rally car that used one of it's bumpers as a cheater tank for a refillable boost as it raced. Can't remember if it was Toyota or Ford. I'm talking about junk though, 200's hp NA boosted to 300-400. Highest qualitay ebay parts. Smooth continuous power without the pops and bangs of an anti-lag.
In a street application with a factory warranty. Sure. In a race application not really. Throw a Chinese turbocharger on a 1.6 L Honda motor and you're making 450 horsepower on stock internals. It's not going to survive 100,000 mi, but that's not the goal.
Engine in my picture is making that using 40psi of boost gauge definitely not stock internals and even still with forged pistons and rods I split the block in half this summer really need to sleeve Honda engines if you want them to last
I first came to your channel for the aviation and began loving it even more watching automotive coverage. I am personally appreciative of your dedication, Greg. What I like most is your no non-sense presentation. As well you cover niche topics that are rarely accurately presented by others or as extensively. Thank you!
Wow, I'm glad to hear that. I wasn't sure how this one would be received. I'm actually going to follow it up with a super short version for those who don't want to learn and just want the quick answers.
Roots blowers were necessary on 2-stroke diesels used on ships, locomotives and some road vehicles for scavenge air. Specifically the EMD 567 and stuff from Detroit Diesel.
@@GregsAirplanesandAutomobiles However the EMD 710 used a mechanically driven turbo using an over-running clutch so at about 70% power the turbo was driven by exhaust only.
The diesel Sherman tanks used two 6-71 GM two-stroke diesels. GM took advantage of the supercharger to blow intake air over the exhaust valves to cool them. On a diesel this doesn't waste fuel as the fuel is injected into the combustion chamber after the exhaust valves have closed.
@@brendonbewersdorf986 They are interesting, but not that complicated. The key factoid is that the uniflow design needs an air-box around the cylinders to force charge air into the side mounted inlet ports.
Only a few minutes in, but you are totally nailing this. My favorite supercharged toy was a 99 Mazda Miata with a 1 liter twin screw. The first twincharged vehicle I was exposed to was a Toyota MR2 making around 500 hp, the infamous Corky Bell turned me on to twincharged madness.
Thank you for this video. Your channel is one of the very few that I only watch when I'm fully awake. You give so much information I have to concentrate. Outstanding.
As a child I had a metal dinky toy model of that car. It's a very memorable shape but I never new what it was. Thank you for another informative episode. 👍😎
You answered questions that I didn't even know that I had! My professional specialty was " Smoke Management Systems" in High Rise Buildings which became my specialty because of my knowledge of piston engines. I'm not a mechanical engineer or even much of a mechanic but I understand basic physics and thermal dynamics. Now after your video I am inspired again to gain further understanding of air/energy and movement all over again! Thank you for your video and effort!
Another great video. With your explanation of benefits of the roots and centrifugal. The first thing that comes to mind is a dual stage setup combining a roots and centrifugal supercharger. Giving the low and high range benefits of both...
@@GregsAirplanesandAutomobiles Honda has just announced a three cylinder motorcycle engine with an electrically driven suoercharger. There is some good info on it at the Cycle World website if you are interested.
Roots+Centrifugal combo has been done a few times in road vehicles (both large trucks, and sports cars), but normally where the centrifugal in question is part of a turbo supercharger. Sometimes to get even more high range benefit they bypass the roots supercharger with a valve at high boost to allow it to be specified for better low end boost and avoid that inefficiency/heat later. Using a turbo as the Aux blower stage allows the pressure to be maintained constant for most of the rev range by simply opening the waste gate in exhaust, instead of needing a variable drive speed system (be that gears, hydraulic or as has taken over almost all modern variable speed implementations, electronic) and the inefficiency that embodies, which saw many WW2 aircraft adopt this approach (but normally with centrifugal "primary" supercharger since they didn't need to operate at high boost on as wide of an RPM range as cars/trucks). Having a roots blower also spools the turbo a lot faster than would otherwise be possible, allowing it to be bigger and more suited for efficiency at the high end, but I think Greg is likely to get into that sort of thing more when/if we get a compound turbo video.
@@GregsAirplanesandAutomobiles Yes, that's the gearbox, final drive and wheel assembly within those drawings. Also, nowadays staging superchargers (be it turbo or mechanical) is called compound charging and it's done quite often with high power diesels.
I am not 100% sure why YT recommended this video to me, but it was absolutely fantastic. Clearly explained in detail, without being boring. Oh, and also understood jet engines now at the same time, which I did not expect.
Amazing video Greg! thank you for putting in the effort. It means a lot to someone obsessed by as you called it, "dormant" technology, possessing theoretical / proven benefits, that lies waiting for someone to re-activate it.
Great! I don't usually watch the auto videos, but the way you intertwined the automotive and aviation applications in this one made it one of your most interesting presentations for me. I really like discussions where technology crossover is part of the format.
Outstanding!! No Alfa intercooler but everything on the intake side has aluminum fins all over it🤔 The BRM is a double sidewinder centrifugal. The old story was that the BRM flopped because the power came on too abruptly making the car uncontrollable, your chart blows that out of the water (methanol) Nice to see something on the Latham an interesting dead end.
BRM had so many problems with their first F1 car they went completely in the opposite tack with its 2,,5. Litre successor and based the engine on the block design of the Rolls-Royce B40 most famously used in the British Army 1/4 4x4 Austin Champ
Not sure what you mean by "sidewinder". The BRM had 2 stage supercharger designed, developed and manufactured by Rolls-Royce for BRM, and is essentially a smaller version of the Merlin and Griffon superchargers. The supercharger impellers were one behind the other, the shaft was parallel to the engine crankshaft.
Great presentation Greg. Re the BRM, Stirling Moss made a recording in which he mentioned that the steering shaft had seven universal joints which compromised road holding. I'll bet it did.
@@waynec3563"Sidewinder" was the American term for their derivatives of the WWII German transverse, variable-speed superchargers, and which was used on planes like the F4U-5 Corsair. I believe that user is just mistaken and confusing the systems.
@@waynec3563 A "Sidewinder" supercharger, as far as I know, refers to the transverse, variable-speed blowers developed in the US, and derived from the German examples used on WWII aircraft. I know the F4U-5 Corsair's auxiliary superchargers were referred to as "Sidewinders". I think the original comment was simply getting the term confused.
Excelent Explanations!! thanks.... Those parts drawings at 34:45 of the 159 are the gearbox (transaxle type) and the rear wheel axle (in fact, it says Gearbox and axle 159 in Italian!)
Great video...reminds me of HP249 by Hugh MacInnes(1987)...had a section on compressor sizing multiple stage turbodiesel systems.This is the only other time that I've heard anyone dive into the deep end of compressor sizing and the associated obstacles that are involved.
Surface Combustion endogas generators came with Roots pumps, and we always took them off and used waukee vane pumps. I never knew why, just that the old timer that taught me, Ron Vircant, taught me to do it that way. I'm going to say that the pulsing of the output was probably the reason, as the waukee is constant flow going into the carburetor.
In the semiconductor field, we use electric Roots blowers to create vacuum, to lower pressure in water chip manufacturing machines, to remove air, and/or maintain a process pressure in process chambers. Electric turbos are used for low volume, low pressure pumping applications. Many other types of pumps, but these two are fairly close related to ICE setups.
Greg, very interesting. Thank you. I used Roots blowers for vacuum source for a material conveying systems. Also used high pressure and medium pressure centrifugal blowers for positive pressure conveying systems. I was not aware of the Roots history..
Its a pleasure to eat popcorn 🍿 and listen to your great exposè. This is where tou excell. Thanks for spending the extra time zoning in on how the dual atage voosting system worked so well on Roots blowers. 52:06 Your last point was a golden foil of vital information.🥝✔️🤜❤🤛
I assume you’re referring to the H16 they tried making later? What a wonderful bunch of goofballs. I do miss outside the box thinking, like Jim Hall, modern day racing is too scientific and not enough “let’s see what happens”
@@rich7787 yeah, between the V16 mentioned here and the H16 BRM has 2 unusual 16 cylinder F1 engines Part of me wants to do the truly insane thing of combining the two approaches. The unusual layout of 2 1.5 litre engines turned into a 3 litre engine but instead of the V8s used for the H16 use the 1.5 litre V16s. Totally nonsensical, I know
Ford considered building the Merlin under license, but did not. Packard built Merlins under license. Ford built P&W R-2800 B series engines under license, like 27,000 of them. Ford also built a V8 tank engine that was based on engineering they did related to their brush with the Merlin. Check "Allied Aircraft Piston Engines"
This was a very interesting video. I didn't know about the concept of "dual-stage" I've seen a few hotrods with stacked blowers and i always assumed it just increased air volume or speed not pressure necessarily. I guess i always assumed that the suck/blow of the 2nd blower would cancel out the pressure, not double it. I love the solutions these old maniacs came up with to go faster with a car thats closer to a tractor than a modern car.
I'm addicted to this video. I hope you can make new ones about other types of forced induction and different types of engines, Greg. Thank you for this masterpiece. 👏🏻🗿 And Happy Holidays! 😁👍🏻
Agree, an engine that operates at sea level and one that has to operates at altitude face fundamentally different problems in regard to what the supercharger has to achieve.
I'm so glad this wasn't one of those terrible videos with AI generated voice. Love seeing the history and the detail behind it, there's always something to be learned. Modern times have favored dual stage or "compound" turbo setups which is equally as fascinating. I had one turbo on my truck that would bark and surge making it difficult to drive and tow with, but simply adding a large second turbo completely changes the pressure ratios inside the smaller turbo and eliminated ALL the drivability issues.
This is going to sound dumb, but this video has been a big help for me to make some seriously bad-to-the-bone coumpound- and twin-charged engines in Automation. I recently designed a 1.8L 3-cylinder at 400hp and passing 2012 emissions. The game doesn't have compound roots blowers, but they do have roots/turbo and compound-turbo. I tried setting the pressure ratio on the blower to 1.0 and it made the watermelon-size turbo spool at 6,500 instead of 2,500 (!!), so clearly the blower was pulling its weight. It's a great game for terminal engine nerds, if you haven't heard of it.
Dual-stage Turbochargers seem to be common on industrial diesel engines these days. At my place of work we have two agricultural tractors that use dual stage turbos, one with a Deere and one with a Deutz engine. The Deutz one has a water-cooled intercooler between the stages and then an air-cooled after cooler.
Greg, that is just a super spectacular piece of research and narration. Easy to understand, relatable to real life and rich in historical details. Many, many thanks. The last part about the 3 and more stages of supercharging is rather psychedelic as it links different technologies of the heat engine via the compression metric. I think that it would be truly delightful to see your take on different heat engine tech in both airplanes and automobiles.
It sounds like "slip" is very much the same thing as surge in a centrifugal supercharger or turbocharger, and it's also the same reason compound turbos exist. Really interesting to see that this technology has been around for so long, and on Roots blowers which I never knew would even benefit from multiple compressor stages. In a turbo application, using two stages will compound the potential pressure ratio. If you would've gotten surge at a 3:1 pressure ratio with a single turbo, compound boost allows you to run up to 9:1 without surge.
Great video!!! I know of one vehicle I have worked on and drove that has a dual supercharging system, though it uses a turbocharger feeding into a supercharger, and is a diesel. The US Army HEMTT line of heavy trucks use a Detroit Diesel topped with a supercharger, topped with a turbo. I was a mechanic in the Army, and also in the National Guard, and operated an M984 HEMTT 8x8 wrecker in Iraq -- one powerful machine!!
Turbocharged two stroke diesels still need the roots blower to scavenge the combustion chamber. My understanding is that the roots blower is still producing only modest boost the same as in a non-turbocharged two stroke diesel.
@@fafner1 All I know is that beast could haul a truck heavier than itself down the interstate at 65mph up hill, flat, did not matter. And it would do even better with a little tweaking on the pump and governor!!
Bravo Greg, excellent as ever particularly liked the epilogue. VW did utilise a ‘twin charger’ system on production cars in Europe ( not sure if they made it to the US market) during the early 2000’s a combination of a super charger and turbocharger.
Yes, Volvo did that as well before they threw the whole company down the drain. However those are examples of turbos blowing into superchargers, which is really quite a bit different and done for a different reason.
Twincharging is known, though still rare, in aftermarket modifications. In most of these cases, a relatively mild supercharger is used mostly to provide boost at lower RPM to offset the "turbo lag" from the turbocharger, which becomes more effective at higher RPM.
I may have seen either, or both? of these cars years ago when I repaired a car elevator at Shelby's car collection on the second floor of his man cave in the LA area. But the overseer was not having any questions or wondering eyes. I was looking down at the Shelby Pony while working. I got to see a gull winged Benz at customers in PV as I put in car stackers. This guy was cool. I worked on rotary/vain air compressors that are based off these supper chargers all with the same employer? Rotary steam engine?
I was just wondering about this engine yesterday..Thank you so much for sharing this..I was even searching out supercharger tech for airplanes as well..I am about to start building a 11928 Morgan?GN special hillclimb car and I am using a BMW opposed twin and I am going to either supercharge or turbocharge the motor..Thanks again-John
If memory serves me correctly both the VW group and Volvo(/polestar) use a twin-charge setup in some of their engines but these are a supercharger + turbo combo I believe.
Excellent content as always, Greg. Back in the 90s/ early 2000s Mazda used something called a Pressure Wave supercharger, i don't think it was particularly successful but it was an interesting device. I daily drive a 2.0 Alfa GT, and there are days where I wish it was supercharged, but I suspect c the amount of work required would be somewhat out of proportion to the gains to be had.
Many thanks as always, Greg, for another video which explained to this non-engineer much that he hadn't understood. I guess you have available the 1964 Institution of Mechanical Engineers paper on the BRM supercharger, by its RR designer and a senior colleague. When the supercharger was designed, the intended max rpm of the engine was 14,000, which turned out to be far too much for the valve gear. It does seem that it was less RR convincing BRM that their supercharger could produce enough boost at 6000rpm, as that it was of such size and potential that it would blow the unmentionables off the engine way below max revs. So pre-swirl vanes were designed and built to flatten off the boost curve above 10,000rpm. Through the BRM management's signature blend of rigidity and incompetence, these were never fitted when the car raced.
Excellent as always Greg. Logistics was part of reason for the USMC using the M4A2 but not so much the fuel availability as is often stated but the Tank it self as the Army had laid claim to the Petrol powered tanks so the USMC selected to takee Diesel as they would be available far sooner. The USSR did request M4A2 due to they use of Diesel in the bulk of there medium and larger tanks. See Chieftains hatch Operation Think Tank.
Hall and Hall in the UK are building 3 new/continuation BRM V16 cars. They seemed to be estimating 550 bhp from initial dyno runs, but these runs were with conservative revs of 10,000.
@@GregsAirplanesandAutomobiles John Owen, the son of the then BRM Formula 1 team principal, received the first of these cars. Thanks for your interesting and detailed videos.
This is art and you should feel good for making this video! I had no idea that the math behind this was so, er, calculable lol. And that's coming from someone who plays automation!
There were several footages around of a 158 Alfetta getting tested. A few days ago, Jim Stokes' Workshop's Facebook page pit up a video of a 158 Alfetta engine being dyno tested. Even with them tuning it on a conservative side, the engine still put up 365BHP at 8,000rpm...
The things that really did in the high performance piston engine as a fighter engine were the aerodynamic limitations imposed by the propeller and the ability of the engine and fuel combination to survive the boost a good supercharger setup was capable of providing. But as with warships at the turn of the 20th Century, the reciprocating engine/propeller combination had reached the limits of what it could give without destroying itself in prolonged use. Airliners clung on to it a little longer, but even they had issues with engines destroying themselves in mid-flight and causing fatal accidents and terrifying near misses (see Air Disaster 4 by Macarthur Job for examples).
With the 5 to 6 gallons a second fuel curve of a Nitro burning top fuel engine. Adiabatic heat is a necessary Evil needed to shear the wet flow and homogenize the fuel air mixture. A lot of guys focus on the O.D. Teflon strips that seal the lobe to the case but I have found that the I.D. Nylatron strips that seal rotor to rotor are much more important. I prefer to only make at most 2 runs on a set of strips. I’m working on a gas ported rotor that uses plenum pressure to seal the rotors much like a gas ported piston uses cylinder pressure to seal a low radial tension ring. I noticed you said that a Roots blower does not make pressure in the bottom of the case. I’m trying to wrap my head around that knowing that a Roots is a positive placement compressor. A lot of manufactures used to restrict the outlet into a small pie shaped discharge area into the manifold plenum. NHRA made a rule against it in the Top Fuel classes to slow us down. My question is does restricting the discharge speed the exit flow up dropping the pressure thus raising theoretical efficiency ? I hate the fact that we have almost zero scientific data in drag racing especially in the Nitro burning classes. I’m not sure if it’s because of the dynamic forces are so high or the fact that a lot of parts are junk after a single run making sensor base line control impossible or to expensive. My father was one of the first guys to make a “Billet” Hemi head in 79. He teamed up with Art Whipple and Walt Austin to create an engine combo that won many championships through the 80’s. I was very fortunate to learn from some of the smartest guys in the sport. That being said you don’t know what you don’t know and I genuinely STILL learn a lot from your videos. I wonder how many watchers truly realize the level of knowledge and information there is in your content. This is kinda like a sleeper channel where I hope people realize that the no frills production masks the legit rocket science content. If you do read this Greg please get in touch because I would love to return the favor and take care of your vip tickets and hotel to any of our races.🙏🏻 I sure do appreciate you sir for your in-depth amazing content! Thanks again sincerely Nick Holm
Hi Nick, thanks for your kind words. I would love to come to an NHRA event. I think there are some in Tulsa this coming year. I live only 30mins from that drag strip.
Also, I didn't mean to say that there is no compression at the supercharger outlet/bottom on the case in a conventional mount, there is. However the Roots blower does not compress air internally like a centrifugal or a screw. It all happens on the outlet side.
The original Roots Blower was manufactured in the Worlds first "Industrial Park" powered by the Whitewater Hydraulic Power Canal. The Roots office driveway is built on top of the old canal raceway today. The plant is still in its original location, next door to Stant radiator caps.
The Cord car was also built in that industrial park. That section of the canal was used for hydraulic power to generate electricity until after WW2. That section was much more highly developed and larger from decades of maintenance vs the original 1800s sections used for transportation.
Awesome video! I would highly reccomend checking out some usb microphones to up the audio quality for your videos. You've got a great voice for voiceovers, let it shine!
DKW used piston superchargers in the late 1930's. Going by memory, there was another conrod along side the conrod that was connected to the combustion piston that drove the supercharger piston.
Sadly, there are fewer and fewer videos on RUclips like this. Originally, we were told that the "information superhighway" was going to be the great educator and a universal source of information. What we now have is a world of clickbait, gambling adverts, trolls and stuff encouraging adults to remain as mental juveniles.
So thank you for this video which fulfils the original brief. I spent thirty odd years in motor sport, primarily building competition engines, but have very little experience of super/turbo charging. I've had this on in the background whilst repairing a vacuum cleaner, but I guarantee that I'll be watching it again while not repairing anything so I can concentrate.
😂 Yes, authoritative bright and concise engineering progression being discussed on interesting race cars... Is not the common girl jumping on a trampoline❤
There has always been a plethora of information irrelevant to you. However, you used to have the Luxury of curating your online experience simply through the problem of having to be specific in your searches. Now, due to the advanced Indexing and Content Delivery alogrhythms, you are exposed to a large amount of information which is irrelevant to you. It's a new spin on Plato's Cave.
2000 to 2010's used to be like that.. its in the last say 10 years all this click bait shit trolling, adverts and politic crap overwhelmed the net..
I miss Smokey Yunick.
...and an appropriate presentation of his projects, i.e. the "hot air" fiero. 😐
You know... as vacuum cleaner is pretty much an electrically super- charger...
I got to see and hear an Alfetta 159 on track at Laguna Seca in 1991 in celebration of Il Maestro Juan Manuel Fangio's 80th birthday. What a GLORIOUS sound that 1.5 litre straight eight made. Fantastic.
I'm jealous.
@@GregsAirplanesandAutomobiles I'm jealous of my old self. I live far from a road course (or even mountains) these days. My first gen Miata misses those roads as much as I do.
Seeing and hearing the Alfetta was a rare treat. I got to speak with some of the Alfa folks, and made friends with one of Fangio's mechanics Guido Moroni even though I don't speak much Italian and he didn't speak any English. He saw me around the car so much that weekend, he joked "hey, a million dollars, and we go to Mexico and the car is yours...).
Fangio was Pure Class as one may have read. Drove his Mercedes GP car so fast on a demo lap (at 80 years old) the driver of the camera car (in a modern sportscar) spun trying to keep up.
Greg you go deeper and longer than all of your peers, and always bring receipts.
I’ve been at Goodwood and saw many vintage cars, and many are memorable, but the sound of vintage Ferraris, Alfas and the V16 BRM’s claimed my heart.
@@williammorris584 Were you there for the hill climb or for the track event (I can't remember which they call each one)? Either way, great sounds. I'd love to hear one of those V16 BRMs with the centrifugal blower in real life, I've only heard them on video.
A Colombo derived 3.0 liter V12 is one of the greatest mechanical sounds to my ear; love the Alfas too of course. Cheers!
taking us from piston engines to jet engines, just by following how good multistage-compression is, that a piston engine simply isn't needed anymore?
masterful
Jet engines are not very suitable for ground transport in terms of efficiency and turning driven wheels.
So the piston engine still has a place and advantages depending on application.
@@AlienLivesMatteron today's vehicles like tanks jet engines are likely to have extra thirst for various fuels. Not a good seller if your car need more than double than a diesel engine.
If jet cars were the way to go, they would have caught on back in the 50s or 60s.
@@AlienLivesMatter Turbines are great for torque, just look at the military applications in Tanks. The Abrams and the T-80 MBTs are arguably the most formidable tanks ever made and they both run Turbine engines which produce plenty of torque.
The problem with Turbine engines in Cars was the fact that Cars have to share space with pedestrians, and that they're nowhere near big enough to displace the heat properly. You ever feel the warmth when standing next to an exhaust? Well ramp that up by about 10 and you'll understand why Turbine cars never caught on.
I saw an old movie that described how the jet was just an existing supercharged engine without the pistons. Which made sense, This discussion really brings home just how close everyone was by the mid 40's to eliminate the piston. THanks!
yep. remove pistons, get a jet engine.
ruclips.net/video/TIP_AIff56Y/видео.html
And now we're just gonna use the battery and starter motor !
@@louisesamchapman6428 just cutting out all the middlemen I guess.... :)
@@louisesamchapman6428 a 400HP starter motor...
Interesting topic. Auto Union also had a two-stage Roots blower in its Type D racing car from 1939.
They went from a 6l single stage V16 to a 3l dual stage V12 and made at least the same power.
The 1947 BRM V16 made a very peaky 600bhp from a 1.5 litre with a single stage centrifugal supercharger.
Mercedes was also running two stage Roots blowers in 1939. Post war Ferdinand Porsche designed and built a rear engined flat twelve cylinder four wheel drive two stage supercharged formula one car for Cisitalia, but it was so complex it led to Cisitalia going bankrupt before it could be raced.
@@georgetillett6549 On the very rare occasion it was running properly. Engineers eventually concluded that very small cylinders don't work well.
I come here for the straight story. Greg never backs off from a complex subject. He might simplify to suit the explanation, but the raw data is there, and it's backed up with sources and genuine understanding. My hat's off, sir!
I just love the depth of content in your vids.
Fell in love with Alpha in the 50's, well before I could drive. Their single minded pursuit of technology, beauty, and performance won me over, and formed my understanding of mechanics and art. When my Italian uncle, who sold used cars, offered me a 1958 Alpha Guilietta Spyder for $400 I was head over heels. Later he would sell me a Fiat 850 Spyder at cost. Neither were fast, but that wasn't the point.
I had a brother 7 years younger than me, and I foisted my ideas on him. Later we would build boats together. Still later we would brainstorm carbon fiber bicycles.
This Fall my brother, Bob Parlee died due to cancer after 25 years as a renowned builder of carbon fiber bicycles.
Peace to you
@@keeneseeley627this was a beautiful story
Well I've been getting the stages backwards since I first took an interest in two stage supercharging as a teen. So thank you for straightening me out at 74 years old, lol.
Andy Granitelli's version of the Novi V8 featured 2 stage centrifugal supercharging and they put out monstrous power at Indianapolis from 62-66. Too much power perhaps because they were treacherous enough in the curves to kill 2 drivers when they only had a single impeller before Granitelli took possession. Drivers were afraid of them because they'd break the tires loose anywhere on the oval track even on straights coming out of the curves.
The high speeds at Indianapolis and the larger displacements make the risks even higher. In '63 Jim Hurtubise started the race taking the lead on the straights but giving it up in the curves on just about every lap. When oil got on the track Hurtubise was the first car flagged though his Novi wasn't leaking. I've always suspected that happened because they were concerned about the Novi's reputation for breaking traction.
Rookie Bobby Unser also drove for Granitelli and there is a RUclips audio only Video of his qualifying run in a Novi that just screams going past the microphone in the stands. Another driver was Top Fuel quarter mile shoe Art Malone. No Novi ever won the ran despite often qualifying in the front row including pole position. They usually broke or crashed.
So I wonder if Granitelli's Novis had an intercooler and If they ran both impellers off the same shaft Merlin style but I wouldn't know where to find that information.
According to "Novi V-8 Indy Cars" by Ludvigsen the Novi's ran with just a single stage compressor. Early Novi's used an intercooler, which was deleted from 1953 on to save weight. Intercooling is generally considered not to be necessary when running alcohol, see the Hoonigan Mustang which reportedly produces 1400 hp with two huge turbochargers and no intercooling.
Greg, you make some of the best videos on the Internet. Thanks
The way you described turbine engines finally made it click for me. I've heard people call them "sentient turbochargers" before but i guess i've just never made the connection until now. Neat.
I've wanted to build a turbine from a turbo, as a separate small engine, to keep another turbo always on boost. Like say, hidden in the trunk.
It's exactly how I came to the realization when I was younger too. The supercharger gives intake and compression, we know exhaust makes thrust and can deliver power to a shaft via a turbine, and ignition is covered by a plug anyway. That's all four cycles. The piston starts to look like an unnecessary middleman, at least in concept when practical realities aren't a factor.
Prior to WWII GE built turbosuperchargers. This led them to being selected to build the first US jet engine.
@@pgtmr2713 This might sound crazy but why not have a large cf paintball tank plumbed to the intake before the compressor. It will really help with spooling the turbo and it will come out at subzero temps so it will help with knock too. There is a drag car that runs on 2 Scuba tanks of normal air at 3000psi. I forgot the exact HP number but it was well north of 1000hp and ran a blistering 1/4 mile. They claimed estimated -20 degree intake temps due to the compressed air cooling down as it drops in pressure.
@@joshuaszeto That is way too extreme. The point is to prove the concept would work. Stored air or nitrous runs out quick unless there's a compressor to refill it with air. I believe there was a rally car that used one of it's bumpers as a cheater tank for a refillable boost as it raced. Can't remember if it was Toyota or Ford. I'm talking about junk though, 200's hp NA boosted to 300-400. Highest qualitay ebay parts. Smooth continuous power without the pops and bangs of an anti-lag.
450hp out of sub 1500cc is is exceptional today! Wow!
In a street application with a factory warranty. Sure. In a race application not really. Throw a Chinese turbocharger on a 1.6 L Honda motor and you're making 450 horsepower on stock internals. It's not going to survive 100,000 mi, but that's not the goal.
@@otm646that easy? what a mastermind
@@otm646and a laptop of course! You can’t forget the laptop!!
Engine in my picture is making that using 40psi of boost gauge definitely not stock internals and even still with forged pistons and rods I split the block in half this summer really need to sleeve Honda engines if you want them to last
@@otm646stock internals will last a week if you are lucky and engine hasn't been abused
I first came to your channel for the aviation and began loving it even more watching automotive coverage. I am personally appreciative of your dedication, Greg. What I like most is your no non-sense presentation. As well you cover niche topics that are rarely accurately presented by others or as extensively. Thank you!
I love this format. The level of detail is wonderful. I often have to rewind to take it all in.
@@jssamp4442 absolutely.
Greg: You're firing on all cylinders at this point -- well done!
Greg this is by far my most favorite video from you!!!
Wow, I'm glad to hear that. I wasn't sure how this one would be received. I'm actually going to follow it up with a super short version for those who don't want to learn and just want the quick answers.
Thanks!
Thank you very much. I appreciate that.
The link between aircraft and F1 is a lot closer and more linked than people realize. Great video. 👍
This was the most fun my brain has had in years. Your videos are always a treat and thank you for maximum effort every time.
Roots blowers were necessary on 2-stroke diesels used on ships, locomotives and some road vehicles for scavenge air. Specifically the EMD 567 and stuff from Detroit Diesel.
Yup, and that's largely where they came from in the early days of supercharged hot rods.
@@GregsAirplanesandAutomobiles However the EMD 710 used a mechanically driven turbo using an over-running clutch so at about 70% power the turbo was driven by exhaust only.
Two stroke diesels are fascinating in and of themselves it would be interesting for Greg to break them down
The diesel Sherman tanks used two 6-71 GM two-stroke diesels. GM took advantage of the supercharger to blow intake air over the exhaust valves to cool them. On a diesel this doesn't waste fuel as the fuel is injected into the combustion chamber after the exhaust valves have closed.
@@brendonbewersdorf986 They are interesting, but not that complicated. The key factoid is that the uniflow design needs an air-box around the cylinders to force charge air into the side mounted inlet ports.
Only a few minutes in, but you are totally nailing this. My favorite supercharged toy was a 99 Mazda Miata with a 1 liter twin screw. The first twincharged vehicle I was exposed to was a Toyota MR2 making around 500 hp, the infamous Corky Bell turned me on to twincharged madness.
Thank you for this video. Your channel is one of the very few that I only watch when I'm fully awake. You give so much information I have to concentrate. Outstanding.
As a child I had a metal dinky toy model of that car. It's a very memorable shape but I never new what it was.
Thank you for another informative episode.
👍😎
I've always wanted something like that Alpha for a daily driver. And I didn't say that was a practical dream.
You answered questions that I didn't even know that I had! My professional specialty was " Smoke Management Systems" in High Rise Buildings which became my specialty because of my knowledge of piston engines. I'm not a mechanical engineer or even much of a mechanic but I understand basic physics and thermal dynamics. Now after your video I am inspired again to gain further understanding of air/energy and movement all over again! Thank you for your video and effort!
This is the best thing I've seen on RUclips in ages. You are a fantastic presenter.
Another great video. With your explanation of benefits of the roots and centrifugal. The first thing that comes to mind is a dual stage setup combining a roots and centrifugal supercharger. Giving the low and high range benefits of both...
I was wondering if a two- speed auto- shifting setup might not help the centrifugals as well.
Yes, absolutely and we are starting to see those in cars and motorcycles.
@@GregsAirplanesandAutomobiles Honda has just announced a three cylinder motorcycle engine with an electrically driven suoercharger. There is some good info on it at the Cycle World website if you are interested.
Roots+Centrifugal combo has been done a few times in road vehicles (both large trucks, and sports cars), but normally where the centrifugal in question is part of a turbo supercharger. Sometimes to get even more high range benefit they bypass the roots supercharger with a valve at high boost to allow it to be specified for better low end boost and avoid that inefficiency/heat later. Using a turbo as the Aux blower stage allows the pressure to be maintained constant for most of the rev range by simply opening the waste gate in exhaust, instead of needing a variable drive speed system (be that gears, hydraulic or as has taken over almost all modern variable speed implementations, electronic) and the inefficiency that embodies, which saw many WW2 aircraft adopt this approach (but normally with centrifugal "primary" supercharger since they didn't need to operate at high boost on as wide of an RPM range as cars/trucks). Having a roots blower also spools the turbo a lot faster than would otherwise be possible, allowing it to be bigger and more suited for efficiency at the high end, but I think Greg is likely to get into that sort of thing more when/if we get a compound turbo video.
Great video as always. The drawings at 34:30 are marked "cambio e ponte" on the lower right, which means gearbox and axle.
Thank you. I'll look at them again with that knowledge.
@@GregsAirplanesandAutomobiles Yes, that's the gearbox, final drive and wheel assembly within those drawings.
Also, nowadays staging superchargers (be it turbo or mechanical) is called compound charging and it's done quite often with high power diesels.
I am not 100% sure why YT recommended this video to me, but it was absolutely fantastic. Clearly explained in detail, without being boring. Oh, and also understood jet engines now at the same time, which I did not expect.
Supercharger squared might be the coolest thing I’ve seen today
Amazing video Greg!
thank you for putting in the effort. It means a lot to someone obsessed by as you called it, "dormant" technology, possessing theoretical / proven benefits, that lies waiting for someone to re-activate it.
Thank you for this amazing video Greg.
Coming from a family that we had 8 Alfas, last was a 159, it is more then just informative and clear.
There’s very, very little on YT that is this edifying while being superbly entertaining.
that alfa looks gorgeous, i would bloody love to have drive in one.
You can still see it in the Alfa museum in Arese, Italy.
I didn’t know how much I wanted to know about compound superchargers!
Thanks, Greg
I've always hoped you would do a video on supercharged Grand Prix cars - thank you!
Great! I don't usually watch the auto videos, but the way you intertwined the automotive and aviation applications in this one made it one of your most interesting presentations for me. I really like discussions where technology crossover is part of the format.
Outstanding!! No Alfa intercooler but everything on the intake side has aluminum fins all over it🤔 The BRM is a double sidewinder centrifugal. The old story was that the BRM flopped because the power came on too abruptly making the car uncontrollable, your chart blows that out of the water (methanol) Nice to see something on the Latham an interesting dead end.
BRM had so many problems with their first F1 car they went completely in the opposite tack with its 2,,5. Litre successor and based the engine on the block design of the Rolls-Royce B40 most famously used in the British Army 1/4 4x4 Austin Champ
Not sure what you mean by "sidewinder".
The BRM had 2 stage supercharger designed, developed and manufactured by Rolls-Royce for BRM, and is essentially a smaller version of the Merlin and Griffon superchargers.
The supercharger impellers were one behind the other, the shaft was parallel to the engine crankshaft.
Great presentation Greg. Re the BRM, Stirling Moss made a recording in which he mentioned that the steering shaft had seven universal joints which compromised road holding. I'll bet it did.
@@waynec3563"Sidewinder" was the American term for their derivatives of the WWII German transverse, variable-speed superchargers, and which was used on planes like the F4U-5 Corsair. I believe that user is just mistaken and confusing the systems.
@@waynec3563 A "Sidewinder" supercharger, as far as I know, refers to the transverse, variable-speed blowers developed in the US, and derived from the German examples used on WWII aircraft. I know the F4U-5 Corsair's auxiliary superchargers were referred to as "Sidewinders". I think the original comment was simply getting the term confused.
That was an absolutely spectacular video. Thank you for sharing this!
Fascinating video as always. It's amazing they could get so much power from such a small engine in the 50s...
And yes, when ya said the Latham supercharger had an "axial flow compressor," it made me think of a jet engine. Very cool.
Absolutely one of the best RUclips channels around
As usual- what an absolutely brilliant, educational, fascinating video. Superb.
One of the best automotive videos ive seen in a while, great job sir you gained another suscriber😁
Excelent Explanations!! thanks.... Those parts drawings at 34:45 of the 159 are the gearbox (transaxle type) and the rear wheel axle (in fact, it says Gearbox and axle 159 in Italian!)
Another great video, great history, lots to think about here, one of the best channels on RUclips
Great video...reminds me of HP249 by Hugh MacInnes(1987)...had a section on compressor sizing multiple stage turbodiesel systems.This is the only other time that I've heard anyone dive into the deep end of compressor sizing and the associated obstacles that are involved.
This was such a pleasure to listen to good job and great information
Exceptionnal work. Thank you for the time you put into this!
Surface Combustion endogas generators came with Roots pumps, and we always took them off and used waukee vane pumps. I never knew why, just that the old timer that taught me, Ron Vircant, taught me to do it that way. I'm going to say that the pulsing of the output was probably the reason, as the waukee is constant flow going into the carburetor.
Will you do a video on "turbocharging 1,500+hp out of 1.5L 4cylinder in 1985". The F1 cars were crazy back then, especially those BMW engines.
In the semiconductor field, we use electric Roots blowers to create vacuum, to lower pressure in water chip manufacturing machines, to remove air, and/or maintain a process pressure in process chambers. Electric turbos are used for low volume, low pressure pumping applications. Many other types of pumps, but these two are fairly close related to ICE setups.
Great knowledgable video. You really know what you are talking about. I had to watch.
I am so happy this is in normal speed! Thanks Greg!
Great content as usual.
Realy great information packed in to a relatively short presentation.
Thanks for all you do Greg.
Great video, thank you very much for putting this together. It's much appreciated!
Another superb Greg's video subject, -but then you never do bad ones Greg.
Greg, very interesting. Thank you.
I used Roots blowers for vacuum source for a material conveying systems. Also used high pressure and medium pressure centrifugal blowers for positive pressure conveying systems. I was not aware of the Roots history..
Roots as vacuum, hard limit, makes sense, volumetric.
Its a pleasure to eat popcorn 🍿 and listen to your great exposè. This is where tou excell. Thanks for spending the extra time zoning in on how the dual atage voosting system worked so well on Roots blowers. 52:06 Your last point was a golden foil of vital information.🥝✔️🤜❤🤛
I like the appearance of BRM and the irresistible need for an unusual 16 cylinder engine
I assume you’re referring to the H16 they tried making later? What a wonderful bunch of goofballs.
I do miss outside the box thinking, like Jim Hall, modern day racing is too scientific and not enough “let’s see what happens”
@@rich7787 yeah, between the V16 mentioned here and the H16 BRM has 2 unusual 16 cylinder F1 engines
Part of me wants to do the truly insane thing of combining the two approaches. The unusual layout of 2 1.5 litre engines turned into a 3 litre engine but instead of the V8s used for the H16 use the 1.5 litre V16s. Totally nonsensical, I know
What a great video Greg! Now I know why blowers love to feed from other blowers! Great charts.
Always look forward to a new video from Greg.
Superb video ! Thanks ever so much from old New Orleans 🏁👍
Good lad, love it, I'm from A ford family, we built the Merlin engines under licence but at heart I'm an Alfa man
I bleed Ferrari red (can't afford one, but love the history and the classic V12 sounds), and Alfa Romeo is where the Scuderia originated.
"we built" lol
Ford considered building the Merlin under license, but did not.
Packard built Merlins under license.
Ford built P&W R-2800 B series engines under license, like 27,000 of them.
Ford also built a V8 tank engine that was based on engineering they did related to their brush with the Merlin.
Check "Allied Aircraft Piston Engines"
In the US maybe, but in the UK Ford's Trafford Park factory near Manchester built over30,000 Merlins.
@koalashark5037
I know my Grandpa was chief engineer, Frank Edward White
Drawing at 34:46 is for the final drive De Dion axle and the integrated gearbox.
Great video and informative for the ab-initio.
Take care
Omg, I finally understand a jet engine. Thanks Greg.
This was a very interesting video. I didn't know about the concept of "dual-stage" I've seen a few hotrods with stacked blowers and i always assumed it just increased air volume or speed not pressure necessarily. I guess i always assumed that the suck/blow of the 2nd blower would cancel out the pressure, not double it. I love the solutions these old maniacs came up with to go faster with a car thats closer to a tractor than a modern car.
Great video, well explained. You are a star Sir.
I'm addicted to this video. I hope you can make new ones about other types of forced induction and different types of engines, Greg.
Thank you for this masterpiece. 👏🏻🗿
And Happy Holidays! 😁👍🏻
Thanks Roddy, I do have other videos on forced induction in airplanes.
@@GregsAirplanesandAutomobiles Checking that out now! Thanks! 👏🏻😁
Yet another video here on Greg's Airplanes and Automobiles that's going to have me dredging the web for related subject matter for the next month.
I'm not really a car guy but as always nice video and very educational. Edit: and I proudly got the boost pressure right.
Ahhh The rabbit hole of referencing aircrafts engines to cars, ends up you need to explain both. And i love it.
Agree, an engine that operates at sea level and one that has to operates at altitude face fundamentally different problems in regard to what the supercharger has to achieve.
I'm so glad this wasn't one of those terrible videos with AI generated voice. Love seeing the history and the detail behind it, there's always something to be learned. Modern times have favored dual stage or "compound" turbo setups which is equally as fascinating. I had one turbo on my truck that would bark and surge making it difficult to drive and tow with, but simply adding a large second turbo completely changes the pressure ratios inside the smaller turbo and eliminated ALL the drivability issues.
This is going to sound dumb, but this video has been a big help for me to make some seriously bad-to-the-bone coumpound- and twin-charged engines in Automation. I recently designed a 1.8L 3-cylinder at 400hp and passing 2012 emissions. The game doesn't have compound roots blowers, but they do have roots/turbo and compound-turbo. I tried setting the pressure ratio on the blower to 1.0 and it made the watermelon-size turbo spool at 6,500 instead of 2,500 (!!), so clearly the blower was pulling its weight. It's a great game for terminal engine nerds, if you haven't heard of it.
Super informative,thx again Greg.
Dual-stage Turbochargers seem to be common on industrial diesel engines these days. At my place of work we have two agricultural tractors that use dual stage turbos, one with a Deere and one with a Deutz engine.
The Deutz one has a water-cooled intercooler between the stages and then an air-cooled after cooler.
This is absolutely fascinating. Thanks!
Greg, that is just a super spectacular piece of research and narration. Easy to understand, relatable to real life and rich in historical details. Many, many thanks. The last part about the 3 and more stages of supercharging is rather psychedelic as it links different technologies of the heat engine via the compression metric. I think that it would be truly delightful to see your take on different heat engine tech in both airplanes and automobiles.
It sounds like "slip" is very much the same thing as surge in a centrifugal supercharger or turbocharger, and it's also the same reason compound turbos exist. Really interesting to see that this technology has been around for so long, and on Roots blowers which I never knew would even benefit from multiple compressor stages.
In a turbo application, using two stages will compound the potential pressure ratio. If you would've gotten surge at a 3:1 pressure ratio with a single turbo, compound boost allows you to run up to 9:1 without surge.
Great video!!! I know of one vehicle I have worked on and drove that has a dual supercharging system, though it uses a turbocharger feeding into a supercharger, and is a diesel. The US Army HEMTT line of heavy trucks use a Detroit Diesel topped with a supercharger, topped with a turbo. I was a mechanic in the Army, and also in the National Guard, and operated an M984 HEMTT 8x8 wrecker in Iraq -- one powerful machine!!
Turbocharged two stroke diesels still need the roots blower to scavenge the combustion chamber. My understanding is that the roots blower is still producing only modest boost the same as in a non-turbocharged two stroke diesel.
@@fafner1 All I know is that beast could haul a truck heavier than itself down the interstate at 65mph up hill, flat, did not matter. And it would do even better with a little tweaking on the pump and governor!!
Bravo Greg, excellent as ever particularly liked the epilogue. VW did utilise a ‘twin charger’ system on production cars in Europe ( not sure if they made it to the US market) during the early 2000’s a combination of a super charger and turbocharger.
Yes, Volvo did that as well before they threw the whole company down the drain. However those are examples of turbos blowing into superchargers, which is really quite a bit different and done for a different reason.
Twincharging is known, though still rare, in aftermarket modifications. In most of these cases, a relatively mild supercharger is used mostly to provide boost at lower RPM to offset the "turbo lag" from the turbocharger, which becomes more effective at higher RPM.
I may have seen either, or both? of these cars years ago when I repaired a car elevator at Shelby's car collection on the second floor of his man cave in the LA area. But the overseer was not having any questions or wondering eyes. I was looking down at the Shelby Pony while working.
I got to see a gull winged Benz at customers in PV as I put in car stackers. This guy was cool.
I worked on rotary/vain air compressors that are based off these supper chargers all with the same employer?
Rotary steam engine?
I was just wondering about this engine yesterday..Thank you so much for sharing this..I was even searching out supercharger tech for airplanes as well..I am about to start building a 11928 Morgan?GN special hillclimb car and I am using a BMW opposed twin and I am going to either supercharge or turbocharge the motor..Thanks again-John
If memory serves me correctly both the VW group and Volvo(/polestar) use a twin-charge setup in some of their engines but these are a supercharger + turbo combo I believe.
Volvo does do that however it's done for a very different reason and set up quite a bit differently.
Excellent content as always, Greg. Back in the 90s/ early 2000s Mazda used something called a Pressure Wave supercharger, i don't think it was particularly successful but it was an interesting device.
I daily drive a 2.0 Alfa GT, and there are days where I wish it was supercharged, but I suspect c the amount of work required would be somewhat out of proportion to the gains to be had.
Many thanks as always, Greg, for another video which explained to this non-engineer much that he hadn't understood. I guess you have available the 1964 Institution of Mechanical Engineers paper on the BRM supercharger, by its RR designer and a senior colleague. When the supercharger was designed, the intended max rpm of the engine was 14,000, which turned out to be far too much for the valve gear. It does seem that it was less RR convincing BRM that their supercharger could produce enough boost at 6000rpm, as that it was of such size and potential that it would blow the unmentionables off the engine way below max revs. So pre-swirl vanes were designed and built to flatten off the boost curve above 10,000rpm. Through the BRM management's signature blend of rigidity and incompetence, these were never fitted when the car raced.
Excellent as always Greg.
Logistics was part of reason for the USMC using the M4A2 but not so much the fuel availability as is often stated but the Tank it self as the Army had laid claim to the Petrol powered tanks so the USMC selected to takee Diesel as they would be available far sooner. The USSR did request M4A2 due to they use of Diesel in the bulk of there medium and larger tanks.
See Chieftains hatch Operation Think Tank.
Hall and Hall in the UK are building 3 new/continuation BRM V16 cars.
They seemed to be estimating 550 bhp from initial dyno runs, but these runs were with conservative revs of 10,000.
That's very impressive.
@@GregsAirplanesandAutomobiles John Owen, the son of the then BRM Formula 1 team principal, received the first of these cars.
Thanks for your interesting and detailed videos.
This is art and you should feel good for making this video! I had no idea that the math behind this was so, er, calculable lol. And that's coming from someone who plays automation!
There were several footages around of a 158 Alfetta getting tested. A few days ago, Jim Stokes' Workshop's Facebook page pit up a video of a 158 Alfetta engine being dyno tested. Even with them tuning it on a conservative side, the engine still put up 365BHP at 8,000rpm...
The things that really did in the high performance piston engine as a fighter engine were the aerodynamic limitations imposed by the propeller and the ability of the engine and fuel combination to survive the boost a good supercharger setup was capable of providing. But as with warships at the turn of the 20th Century, the reciprocating engine/propeller combination had reached the limits of what it could give without destroying itself in prolonged use.
Airliners clung on to it a little longer, but even they had issues with engines destroying themselves in mid-flight and causing fatal accidents and terrifying near misses (see Air Disaster 4 by Macarthur Job for examples).
Really well presented.
Thank you...a very interesting analysis!
With the 5 to 6 gallons a second fuel curve of a Nitro burning top fuel engine. Adiabatic heat is a necessary Evil needed to shear the wet flow and homogenize the fuel air mixture. A lot of guys focus on the O.D. Teflon strips that seal the lobe to the case but I have found that the I.D. Nylatron strips that seal rotor to rotor are much more important. I prefer to only make at most 2 runs on a set of strips. I’m working on a gas ported rotor that uses plenum pressure to seal the rotors much like a gas ported piston uses cylinder pressure to seal a low radial tension ring. I noticed you said that a Roots blower does not make pressure in the bottom of the case. I’m trying to wrap my head around that knowing that a Roots is a positive placement compressor. A lot of manufactures used to restrict the outlet into a small pie shaped discharge area into the manifold plenum. NHRA made a rule against it in the Top Fuel classes to slow us down. My question is does restricting the discharge speed the exit flow up dropping the pressure thus raising theoretical efficiency ? I hate the fact that we have almost zero scientific data in drag racing especially in the Nitro burning classes. I’m not sure if it’s because of the dynamic forces are so high or the fact that a lot of parts are junk after a single run making sensor base line control impossible or to expensive. My father was one of the first guys to make a “Billet” Hemi head in 79. He teamed up with Art Whipple and Walt Austin to create an engine combo that won many championships through the 80’s. I was very fortunate to learn from some of the smartest guys in the sport. That being said you don’t know what you don’t know and I genuinely STILL learn a lot from your videos. I wonder how many watchers truly realize the level of knowledge and information there is in your content. This is kinda like a sleeper channel where I hope people realize that the no frills production masks the legit rocket science content. If you do read this Greg please get in touch because I would love to return the favor and take care of your vip tickets and hotel to any of our races.🙏🏻 I sure do appreciate you sir for your in-depth amazing content! Thanks again sincerely Nick Holm
Hi Nick, thanks for your kind words. I would love to come to an NHRA event. I think there are some in Tulsa this coming year. I live only 30mins from that drag strip.
Also, I didn't mean to say that there is no compression at the supercharger outlet/bottom on the case in a conventional mount, there is. However the Roots blower does not compress air internally like a centrifugal or a screw. It all happens on the outlet side.
The original Roots Blower was manufactured in the Worlds first "Industrial Park" powered by the Whitewater Hydraulic Power Canal. The Roots office driveway is built on top of the old canal raceway today. The plant is still in its original location, next door to Stant radiator caps.
The Cord car was also built in that industrial park.
That section of the canal was used for hydraulic power to generate electricity until after WW2. That section was much more highly developed and larger from decades of maintenance vs the original 1800s sections used for transportation.
Small section operates today; Metamora and Laurel dam.
Thanks jhoncho, I didn't know that.
Oh Roots is their name! I always imagined it was because it tapers the air through the combining. lol Thanks!
Best channel on RUclips!
Awesome video! I would highly reccomend checking out some usb microphones to up the audio quality for your videos. You've got a great voice for voiceovers, let it shine!
Great video, nailed it
An old jet engine mechanic I worked with told about his instructor used an old roots blower mounted to a bench and turned it into a jet engine .😮
Excellent. Thank you.
DKW used piston superchargers in the late 1930's. Going by memory, there was another conrod along side the conrod that was connected to the combustion piston that drove the supercharger piston.