P-51 Mustang vs. Fw 190 D-9

The P-51 Mustang and Fw 190 Dora 9 are surprisingly close in performance. It' surprising because the Mustang had a lot of advantages in supercharging, fuel, charge cooling, and a big edge in production quality, but the Dora comes through with displacement, RPM, MW-50 and a decent airframe.
I think just about every single article or video about the P-51 talks about how the installation of the Merlin engine turned it into a great fighter. That's not false, but there is a lot more to it, and the US contributions to the Merlin side of the story are almost never mentioned. I'll address some of that here.
The video was getting too long, which happens a lot, so I only covered speed and engine power. If the video does well, I'll make a follow up covering climb, turn performance and other factors.
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Corrections and Additions:
North Korea uses meters for altitude, I simply forgot about that country
Carb heat kills performance. I was speaking from the top of my head in general terms and not in reference to a specific fighter. For Merlin or Allison powered planes it's not really a factor. That said, fuel injected engines have an advantage in that they don't need carb heat, either as something selectable by the pilot or a source of heat that runs all the time to prevent icing.

[@toomi195]

Not all of your viewers are old :) I'm 20 and I'm really enjoying your technical videos. Keep it up!

[@GregsAirplanesandAutomobiles]

Thanks, according to youtube's data, this channel gets people in from about 16 on up, I'm pretty happy about that.

[@shawnw1291]

Looks like Im quite young for these kinda video,eventhough I didn't understand some of them but at least I get the idea. I love these videos and so informational. Oh and I'm 15 by the way ;)

[@conorf8091]

Greg's Airplanes and Automobiles I bet a lot the younger age group are war thunder players also 😄

[@adamliu2246]

I am 24 yesssss

[@aussie_t0min8t0r]

Greg's Airplanes and Automobiles you got lower than 16 mate I’m 14

[@Jkend199]

The ONLY youtube channel (that I've ever found) that does "real" comparisons between WWII aircraft, explaining from actual period source material the actual turn rates and actual speeds at particular altitudes ext. What your analysis shows (in my opinion) is that the various planes of WWII were very evenly matched, the performance numbers are derived from various advantages, superior displacement, aerodynamic advantages, supercharger or turbocharger designs ext, but no matter how the performance is achieved the general performance characteristics of the major types of all nations was generally very similar. To me this says, its not the planes that determine the outcome of the battles, its the pilots and the tactics, the logistics and maintenance because the planes are remarkably evenly matched from a performance standpoint. The 10-1 kill ratio's aren't due to inherent advantages in plane design, they are well trained pilots in well maintained aircraft with good logistics facing poorly trained opponents with poorly maintained equipment and logistical problems. The German's had aces with 300 kills, but these men flew until they died... and their successors were never able to replicate those results because they could never be trained and prepared sufficiently. Japan had the same problem, they could never train pilots quickly enough to make up for the ones lost and so the quality of their pilots steadily eroded while the US sent Aces (25 kills) back home to train new pilots allowing the US to maintain the quality of its pilots throughout the conflict. Everybody wants to argue which plane is the best, the truth is, they were all excellent and all got better as the war progressed but it wasn't the planes that won the battles, it was the men that flew and maintained them, and the logistical support making available spare parts fuel and ammunition. Obviously I am fascinated by the technical advances in aircraft design during this period and I love the way you are able to explain how this model introduced this design innovation which changed this performance parameter in this way, shows the steady technical advances made by every nation at the time, I find it fascinating. I hope at some point you decide to talk about the P-38, I would love to know how it stacks up by the numbers given that it is so much larger than the single engine types. Luv the channel Greg James in CA

[@benjaminmiddaugh2729]

The one thing you left out are numbers (unless you're including those in logistics). I don't remember seeing a graph of kill ratios versus number of aircraft being brought to bear, but by the end of the war the allies had significantly more planes and pilots to bring to bear, which would only have compounded the other advantages you've already mentioned.

[@squidwardtentacles244]

A P-38 or a Tempest video would be really nice. I would also love to see a video purely based on wing shapes and designs. Like the advantages of the elliptical wing Spitfires used. Or which airfoil shapes grant which advantages like the "laminar flow" wings americans liked to use so much. And also maybe even construct the "ideal subsonic fighter wing" based on the things we have learned about it. Though that may differ based on what the plane is built for.

[@exsappermadman25055]

The people making the machines and the people who operate them win wars. WW11 is thee most just war in history while also being the time of the most technological advances in human times. Britain got involved because Winston knew his enemy and America got involved because it was attacked. The old world joined up with the new and kicked some serious arse so that we can all type some rubbish on the net as free people, unlike in some countries today......

[@Mike-eq4ky]

Greg, yes... Please consider giving the P-38 the same Love you've given the P-47, which i now have an even greater appreciation for. Just the discussion of the Compressibility gremlin will make it worthy of your outstanding and unique treatment. And the Turbo vs. Supercharger adoption. Tricycle landing gear. First 400mph fighter. And... Why it never received (two!) Merlins although this fantastic video gave some more insight... I was not aware of the Merlin Vs. Alison P-40s and thanks to you i continue to learn something new every day!! 😊

[@amerigo88]

@James Kendrick - clarification - an "Ace" is defined as a pilot who has achieved a total of five confirmed kills in combat. Given all the risks of air combat in WWII, this is a significant accomplishment. For many reasons, there were few American aces with more than about 15 confirmed kills and they were indeed rotated back to the USA to provide instruction to new pilots, passing along lessons learned. One issue historians tend to gloss over is the tremendous danger of just flying anything in WWII, without people shooting at you. It seems like I have seen multiple fighters that suffered more losses in accidents than they did in combat. This is somewhat understandable for carrier-based aircraft, but it affected many aircraft. The Bf-109 was a bit of an "expert pilot's" aircraft with its narrow landing gear that led to many ground loops and crashes by rookie pilots - often fatal crashes. I expect the Spitfire was somewhat unforgiving with narrow track landing gear and absolutely atrocious pilot visibility on the ground until the tail wheel lifted from the runway. Simple, rugged, reliable, easy to fly were very important characteristics for reducing all of that "wastage." The B-17 checked all the boxes, but the B-24 was a real handful and suffered many fatal crashes in training and in combat. The B-26 Marauder was also quite dangerous while its bugs were worked out and the wing area increased. The F4U Corsair took so long to be made safe to fly from aircraft carriers that it spent more than a year as a land-based fighter. Your family member killed while landing after their first combat mission is just as dead as if they had been killed by flak over the target on their 20th mission. Maybe someone could really analyze the "wastage" rate on USN aircraft carriers during WWII. IIRC, it wasn't unusual for an aircraft carrier to lose about 10 percent of its aircraft per month to accidents even when not in a combat zone.

[@karlvongazenberg8398]

2:30 As a side note, late war the Hungarian-built Bf-109G were in high demand by German units, because the Rába factory was one of the few ones, which made by solely professional employees (instead of using partially or fully forced labor).

[@engineermerasmus2810]

So that is not something only I heard

[@stevenhoman2253]

Very interesting. It proves the point that although you can take he horse to water, you cant make him drink. Slave labor is a wicked abomination and always came back to bite the German industries that applied it from my reading of it.

[@spindash64]

It seems the Germans forgot that putting the responsibility for the war effort in the hands of someone who wants you to _lose_ is not a strategically sound decision. Intimidation can only do so much when they know you intend to kill them either way.

[@dheemanrajkhowa2866]

Listening to Greg talk about technical comparision between aircrafts makes me feel like I am taking a design course and listening to a seasoned aeronautical engineering professor at college. Thanks Greg!

[@stevenhoman2253]

I agree with you. He really knows his chops. His thorough analysis is always a cheerful change from overly simplistic explanations.

[@Bcso591]

As an 18 year old I feel extremely blessed for finding your channel. I've been always looking for highly detailed videos on topics like this but never got anywhere. A bit sad that very very few are as interested as I am in technical/historical subjects. I really hope you don't stop making these videos for a long time, it's a true gem to me

[@GregsAirplanesandAutomobiles]

Thanks Bacsa.

[@stevenhoman2253]

Ho son, you wont go wrong with Gregs investigative style, of both technical and historical data. Dont mind your friends it is really their loss that you have a sharper and keener mind then they have. Just try not to rub it in too hard.

[@FilmTheAntR11]

I'm 21 and in training to be an aviation mechanic, we still use the old slide films from the 40s and 50s for some of of r lectures. You just can't beat some of the knowledge they had back then.

[@GonzoDonzo]

I believe its because they actually understood everything in their own mind. Now computers are relied on for even basic things.

[@veggeubbe8054]

Congratulations by the way for reaching 1 millon views on the 109 vs p 51 speed video. Thats really impressive considering it's such a niche topic

[@GregsAirplanesandAutomobiles]

Thanks, I was surprised it did that well. I'm certainly happy about it.

[@briancavanagh7048]

I don't consider my viewing pleasure as niche!

[@sc1338]

Greg's Airplanes and Automobiles have you thought about doing a video about the XB-70? It’s hard to find good information on it, and I’d love to here your in depth style on it.

[@paulslevinsky580]

@@GregsAirplanesandAutomobiles Hey Greg, you should do a segment on how the little short-wing pipers (with milk stool landing gear) can fly faster than their contemporaries on the same or less power.

[@Hell-On-Wheels]

The FW 190 D9 was the best piston engine fighter of World War II, according to fighter pilots, aces and test pilots like Eric Winkle Brown and Chuck Yeager. There was an interview with BGEN Chuck Yeager, he was asked about his experience at Wright-Patterson in 1945-47, and especially about flying captured Axis aircraft. "Which was best?" He replied quickly: "That long-nose Focke-Wulf was maybe the best piston-engine fighter I ever flew. As long as you stayed below 25,000 feet."

[@TheJacobshapiro]

It’s not all old people! I’m an engineering student and I love your videos. It’s refreshing to see someone go in-depth when so many channels about wartime aviation just quote the same tired tropes we’ve all heard a million times. You’ve also taught me tons about forced induction which has been helpful.

[@GregsAirplanesandAutomobiles]

Thanks, that's exactly why I am making this channel. I don't want this technology to be forgotten. We do have quite a few younger viewers here, the data shows that this channel appeals to people from 15 well into the 80's. So when I make a video I have to keep that in mind, I can't assume everyone has seen a slide film. Thanks for being here.

[@TonboIV]

Damn. The Dora-9 is one seriously sexy beast! I mean, you wouldn't think an inline engine in a round cowling would make for an attractive airplane, but it somehow looks all long lean and sexy.

[@GregsAirplanesandAutomobiles]

I think so too, I plan to talk about that round cowling in another episode.

[@BoltUpright190]

Personally I'm in love with the D-13. Yellow 10 Rules!

[@GregsAirplanesandAutomobiles]

Yes, that smooth cowling and dual stage triple speeds really make it something special.

[@andreborges2881]

You should seriously check the Focke Wulf Ta - 152. An evolution of the Dora concept, the most spectacularly fabulous WWII plane.

[@paythepiper6283]

@@andreborges2881 Greg has already done a video of the Ta 152H

[@AdurianJ]

Sweden flew the P51B/D and DB605 engines and half of the DB605 engines where Swedish built and in peacetime conditions. So if one wants to compare the Bf109G6 vs P51D that would be a great source. They seem to both have been flown on 100/130 aviation fuel which is the regular fuel used by airlines all over the world post war. But the Swedish Mustangs should have been flown at least a short while on the equivalent of B4 fuel as Sweden used fuels in the 75-90 octane range during the war.

[@smyrnamarauder1328]

we turks did that too with Fw-190 A-3s thanks to Truman help.But some idiot decided to scrap them to make pots from them...

[@dragoonTT]

Ahmet Arslan , very unfortunate. History should never be destroyed.

[@asiftalpur3758]

@@dragoonTT tell that to the British who scrapped the legendary Warspite.

[@sheritonn5019]

@@asiftalpur3758 And to the Americans that scrapped the lengendary Enterprise.

[@ATKDelibalta]

@@smyrnamarauder1328 Truman help came with the condition German weapons be scrapped. Of course they should have saved one or two for museums but then there was severe shortage of aluminum.

[@magoid]

A while ago a couple of us asked you why the German engineers got stuck with 3 blade propellers while Americans and British jumped to four to five blades. After a bit of googling, I believe I got the answer. Turns out that not only the Germans had kept the 3 blade design, the Soviets did too. And what all of them had in common is guns firing trough the propeller arc. After a bit of research, the only operational fighter I saw with a four blade propeller and nose mounted guns was the Nakajima Ki-84, but it was a very thin four blade design.

[@Spectre407]

The P-38 kept 3 blade prop

[@Tamburahk]

number of blades is science of its own, i can assure you that firing through propeller wasnt the issue of it but jsut a side effect

[@charlesjames1442]

I'd suspect economics. Three is cheaper than four.

[@Tamburahk]

@@charlesjames1442 nope, its about propeller aerodynamics and efficiency and usage of torque and power of engines

[@kimmoj2570]

German interrupter gear was top notch (actually it worked in reverse, not blocking firing, but instead firing the guns when prop was clear and firing button demand was there), and MG 131 was electrically primed = easy to control exact time of firing. 4th blade may had decreased RoF a bit, but doable.

[@Kollider115]

I am always blown away by your content, and and super excited for comparisons like these going into the future! Awesome as always!

[@Kollider115]

After finishing it, my only critique would be the lack maneuverability data on the aircraft. It focuses a lot on the speed and power which is completely valid, climb, turning and firepower also is import in full comparisons. This is still a great piece on the engines and straight line speed. I am curious if there is a follow up, or if data is too scarce

[@GregsAirplanesandAutomobiles]

Hi Kollider. You are of course correct. However including climb, turning and firepower would have made this a four hour video if I went into those things in detail. Don't worry though, I will over all of those things in future videos, I'm just not sure if it will be a part of the main 190 series or if I'll turn this video into a comparison series of Dora vs. Mustang videos.

[@petermuller3995]

@@GregsAirplanesandAutomobiles Having videos for each plane would alow the viewer to compare them.

[@SChrisSD]

@@GregsAirplanesandAutomobiles Hi! I have a question regarding the superchargers swirl throttle being a soviet development which germans borrowed. From what i have read the soviets were primarily borrowing german developments regarding engine technology, engine automation and else. Is there somewhere more in-depth genealogy of the superchargers history overall? Thanks, very nice videos!

[@francoistombe]

Love Greg's technical details and historical reality over popular mythology. As a old time diesel guy I have always found thinking of compression ratio as expansion ratio to be more useful in explaining the role of this ratio in power and efficiencies. It's like comparing different barrel lengths on guns firing the same cartridge.

[@gort8203]

Greg, I'm so glad you mentioned the often overlooked U.S. contribution of high octane fuel to the success of the Merlin..

[@GregsAirplanesandAutomobiles]

Thanks Gort. I get tired of seeing in every single article on the P-51 about how the Merlin came in and saved the day, but never the full story.

[@drawingboard82]

It's not clear to me why the USA had high octane fuel and Europe and particularly Germany didn't. Can someone explain?

[@gort8203]

@@drawingboard82 I don't know that many details, but as I understand it the U.S. held a patent on the octane boosters used to raise the octane of gasoline distilled from lower quality oil stocks, which gave the U.S. a head start in developing capacity to mass produce such fuel. (It may have been Shell oil due to the influence of Jimmy Doolittle in the 1930s, but don't quote me on it.) Germany had acquired the license for the process, but their supply of suitable stocks of oil and other additives was restricted during the war. As the arsenal of democracy the U.S. was pumping the stuff out in comparatively large quantities. We know Germany had to turn to synthetic fuels, but I read they did have 100/150 octane C-3 fuel by mid war, and still managed to have 100/130 octane C-3 fuel even late in the war, but I'm guessing not in the quantity desired. More data on actual quantities could help with the picture here. Overall, I think the most significant factor in the near doubling of aero engine horsepower by the end of the war was the increase in octane that allowed use of higher manifold pressures.

[@drawingboard82]

@@gort8203 thanks Gort, that's handy information. It comes up a lot that the high octane fuel really helped, it seems like the Germans should have put effort into development of it.

[@gusty9053]

@@drawingboard82 The issue was that Germany needed more fuel that it could get even more so as the war progressed and the number of fuel eaters grew (trucks, tanks, SPGs, planes, submarines). At some point i think a third of all the oil came from Romanian oil fields and Romania was not exactly a "world class oil exporter" during the interwar period. The Crimean campaign was so that Germany could seize rusian oil fields. They lost a whole army group basically trying to capture them.

[@j.w.greenbaum]

Something I should note: my paternal grandmother's first husband (KIA 2/2/45 in Hausach while trying to make a wheels-up landing of a P-47D), 1st Lt. Albert W. "Bummy" Pines, actually did get his only aerial kill of a Focke-Wulf Fw-190 of some variant in a P-47D of the 315th Fighter Squadron ("The Crusaders"), 324th Fighter Group, 12th Air Force. We don't know what variant it was, but we do know it was not an overclaim; multiple pilots actually saw it disintegrate in the same manner as the tail was basically shot off and the port wing pitched upwards and it started something of an aerial cartwheel as it was coming apart and his old wingman, 1st Lt. Mike McGrath, who lived through 2009, I believe, was the guy whose life he saved; the Fw-190 was shooting at him and then, all of a sudden, it wasn't and he realized Bummy had gotten it. But that's not really the point. When Mike and Bummy both landed at Luneville, since they were actually flying a fighter-bomber mission against railroad targets, well, Mike was very much aware how difficult it was for a P-47D pilot who was maybe 800-1,000 feet BELOW the Fw-190 to shoot it down. So he asks him "how the hell did you do that?" Bummy, as recollected by Mike many years after the fact, admittedly, though it does match Bummy's foul mouth and laconic sense of humor: "The [bleep] if I know." Apparently, shooting down an Fw-190 of any kind was considered pretty impressive. Love a lot of the US contributions to the Merlin that you never hear about. The ultimate Packard Merlin, V-1650-9 that went into the P-51H I know you'd call a superprop, was almost "a Merlin, if American engineers had designed a Merlin", where yeah, it had more similarities than not with the Merlin 100-series, but it was its own engine. But even the V-1650-7 powering the P-51D was not a part-for-part copy of the Merlin 66, no matter how many times I've seen "oh, it was just a Merlin 66".

[@jeromestern8225]

Greg's Video never fail to be fascinating. He puts together the pieces in his most detailed manner. It would be equally fascinating to see a video about how the germans tried to make the BMW 801 radial engine a good performer at altitude. They were experimenting with turbo-supercharging but never got anywhere near a convincing result.

[@NotDumbassable]

They did develop an external scoop for the BMW801 supercharger for High-Altitude fighting, it added about a km of acceptable performance on top of the original one at acceptable cost at low alts. It was used by individual pilots as a Rüstsatz, but my guess would be that it just didn´t add enough performance to replace the 109.

[@askme5805]

Greg's car has 1,4 litre(85,4cui) but these engines have almost 40x biggger discplacement :) BMW 801 41,2litre (2, 255cui) so does DB603 44.52 L (2,716.9 cui) :))

[@Mike-eq4ky]

I don't care what era this is from, it's a great education in the realities of engineering. While science is a study the possible and why things work, engineering is the art of application, and a study in practicality. The years from 1935 to 1946 and the evolution of the airframe and powerplant technologies is one of the best examples of the role of engineering and compromise, with necessity once again being proven the mother of invention.

[@nexpro6118]

So sad how the merlin used a carburetor. Ugh, gross. Lol like, you dive too steep, maneuver rapidly/quickly, than you chock the carburetor of fuel.....so dumb. Fly too high, you can freeze the fuel in the carburetor walls. Fuel gets too hot, you can have vapor lock. Not to mention, it's bad in fuel efficiency compared to the fuel injection. Also, if the fighter had water injection, then how would you change the fuel mixture rate to better Mix the extra air with extra fuel.....

[@kiwidiesel]

@@nexpro6118 Yeah the carburetor did have some quirks that when directly compared to injection looks inferior but injection was very early tech then and the negative g effects that caused issues with the carb were sorted with the advent of the throttle body and the addition of miss shilling's orifice. Vapor locking is just as relevant with injection systems and mixture rate is infinitely adjustable with carburetor also solving your issues with adjustment when using MW50. ABout the only thing neither system can change is ignition timing.

[@StarSwisss]

I'm an 18 year old student studying to be an aeronautical mechanic. Next summer I'll be starting an internship working on world war 2 planes to keep them flying, and your videos help a lot and always keep me engaged.

[@lauriepocock3066]

'we don't have data on a low octane Merlin' Oh yes we do, Rolls Royce Meteor. 'its R-R Merlin origins, the Meteor was very lightly stressed and reliable. With the introduction of the Meteor engine in the Cromwell, the boost to 550 horsepower (410 kW) gave the vehicle exceptional mobility and speed.' many of these engines were ex aircraft engines or components

[@alan-sk7ky]

😉

[@nickdanger3802]

"The Merlin had its supercharger, reduction gear and other equipment removed from its crankshaft, greatly simplifying its construction." en.wikipedia.org/wiki/Rolls-Royce_Meteor#Engine_design

[@julianneale6128]

@@nickdanger3802 also it was quite detuned with different compression ratios and different materials. I also think the Meteor was only limited to 2600 rpm as opposed to 3000 rpm for the aero engine.

[@petervollheim5703]

I was friendly with a WW2 P51 veteran, whose 1st mission was at 2:30am on D-Day. His group (361FG), was later attached to Patton's drive across France, so he did mostly ground attack. He told me that he wished he flew the P-47 for that kind of work. Toward the end of the war, he encountered a, "long nosed FW-190". Not sure if he went to war emergency power, but he said that FW-190D ran away from him. I have a couple more dogfights that he got into - if there is enough replies, I'll detail them here. Greg - awesome videos, really stellar. Thank you.

[@FiveCentsPlease]

+@peterwolheim5703 The Dora model had excellent acceleration compared to the A model.

[@LuqmanHM]

Please help gave us more details!!!!

[@panzerofthelake506]

Maybe the Dora was diving so it has excess speed

[@auroraRealms]

I am sure the pilot in the FW ran away, because he knew that that was the only way he was going to survive.

[@SchwarzAA]

when you said slides-show in the 70s I laughed, we had it in the 2000s XD, they replaced it in 2003 with small TVs am from Saudi big fan of you Greg and your work

[@GregsAirplanesandAutomobiles]

Thanks, I spent a week in Rihayd once. My employer didn't allow us to leave the hotel, but overall it was nice. Great hotel, great service and food in the hotel.

[@SchwarzAA]

@@GregsAirplanesandAutomobiles if you had the chance to visit it again try to go and see the city and try local food (Kabsa) .

[@mpetersen6]

@@GregsAirplanesandAutomobiles They went well with the overhead projectors

[@michaelskywalker3089]

Yes, they should have been phased out by the early 2000's, but when I went to College in 1996 in Ontario, Canada they still had something called microfiche in the library where reference materials, principally newspapers and magazines were projected onto tiny reels of film.

[@mpetersen6]

@@michaelskywalker3089 The problem comes when there's a tech upgrade. Older information may not be readable. I think I've got some 3.5 floppies somewhere. Same thing if you have stuff on Zip discs. But it could be worse. Around the same time as Zips came out there was a competitor called Super Discs. The nice thing about the Super Disc drive was it would also read 3.5 floppies. Believe it or not there are still people using 3.5 floppies. Primarily they are people using older stand alone CNC conversions of milling machines, lathes, plasma cutters etc. en.wikipedia.org/wiki/SuperDisk

[@geoffreyryansdeckjams9653]

The P-51 D had was a vary different airplane than the earlier models. The "bubble" canopy is the most obvious but they also had greater affective virtical fin area , and thicker wings to house the browning M2 machine guns in it's "normal" position. I have read of complaints from pilots saying the the "D" model had "leaky" fire wall seals that made them vary hot at low levels and just no longer "fun" to fly.

[@drawingboard82]

Greg you're the best. My girlfriend unexpectedly and brutally broke up with me this weekend. On top of my brother dying. And lockdown. And I had to travel back to Scotland after the breakup. I was literally suicidal when you premiered this. You have saved my life. It's not an exaggeration and I really want you to know the effect you have on people. Thank you from the bottom of my heart.

[@asiftalpur3758]

Stay strong.

[@GregsAirplanesandAutomobiles]

I'm sorry all this happened to you. Loosing a sibling is tragic. Loosing a girlfriend always seems about 10x worse than it actually it. I'm not discounting it, but in my experience, it's going to be an opportunity to upgrade.

[@drawingboard82]

@@GregsAirplanesandAutomobiles thanks Greg. You're absolutely correct. Keep up the good work!

[@Splattle101]

According to Stanley Hooker in his book 'Not Much of an Engineer', (ISBN 978 1 84797 325 2), the 60 series Merlin began in 1940 when the RAF asked for a turbo supercharged Merlin to deliver 1,000 HP at 30,000' for a pressurized Wellington bomber. While RR had well developed tech and tooling for mechanically driven centrifugal compressors, they'd be starting from scratch with an exhaust turbine. However, RR had the larger Vulture motor that delivered 1,000 HP at 30,000'. Long story short, they put the Vulture's compressor in front of the compressor of the Merlin 45 (the engine in the Spitfire V) and - with the after cooler - they got the requisite 1,000 HP at 30,000'. This Merlin 60 was tested in a Wellington bomber. RR suggested the engine be tried in a Spitfire and by mid 1941 they flight tested it in a Spitfire Mk I, which led to the Spitfire IX reaching service in June 1942. By the time the Mustang was in production, Packard was already producing Merlin XXs (or the Packard equivalent) under license. Given the interest in 1942 in the way the Merlin 61 transformed the performance of the Spitfire, it was hardly a leap of imagination to wonder what would happen if you put one in a Mustang. Neither was it much of a leap to get Packard to produce it. The conversion done by RR was literally that: a conversion. It even used a prop from a Spit IX. The RAF were exploring the feasibility of converting their existing fleet of approx 600 Mustang Is to Merlins. The new North American P-51B was a re-design rather than a conversion. Thus it got a deepened fuselage, redesigned induction and cooling systems, redesigned wing root, etc etc etc. It was a major undertaking.

[@hertzair1186]

Little known fact....both fighters were designed by German engineers...Edgar Schmued for the P-51 and Kurt Tank for the FW-190.

[@anttitheinternetguy3213]

Is that so. Now i Have to imagine alternative history with Fw-190 with star and bars and Mustang with swastika and splinter camo

[@sirbader1]

@@anttitheinternetguy3213 There were examples of both captured and repainted.

[@TRUMP_WAS_RIGHT_ABOUT_EVRYTHNG]

Guy named tank designed airplanes. That is funny.

[@givenfirstnamefamilyfirstn3935]

Boeing was from a German-Austrian family.

[@BlueMax109]

P47 was designed by Russian immigrants as well

[@gort8203]

RE: The Packard Merlin being a direct clone of the RR Merlin. I read that when Packard acquired the engineering drawings and specifications from Rolls Royce they found they would not work with Packard production methods. They had to redraw all the blueprints to tighter tolerances. As I recall, tolerances of the Rolls Royce parts were too coarse and the parts usually required some degree of hand fitting before they could be installed, which was normal for Rolls Royce craftsmen. For efficient mass production Packard needed the parts to fit interchangeably without hand fitting, so they tightened the tolerances on the parts.

[@GregsAirplanesandAutomobiles]

That's absolutely true. Rolls Royce was hand fitting the parts for every single engine. Packard improved it mainly by using modern production techniques.

[@drawingboard82]

@@GregsAirplanesandAutomobiles ditto the Merlin's made by Ford UK. You can read about it in an excellent book called "not much of an engineer" by Stanley hooker.

[@davidelliott5843]

Rolls Royce was capable of manufacture to tight tolerances, they just did not see the point as they had the skilled trades to sort and fit the parts which best matched.

[@seth1422]

The next chapter in the story, after being told by Packard the existing plans are not precise enough, is actually pretty funny. Instead of redrawing the plans, Rolls Royce simply shipped an entire Merlin engine to Detroit. Which worked, but was also a bit passive aggressive.

[@colderwar]

@@drawingboard82 Hooker redesigned the supercharger arrangement for the Melrin, didn't he ?

[@dsdy1205]

"Greetings this is Greg..." Now there's a name I haven't heard in a long time...

[@JohnRodriguesPhotographer]

The p51a design specification was for what the British called rhubarb attacks or missions. What we would call today ground attack. The specification called for the aircraft to fight from sea level to about 15,000 ft. The choice of the Allison was partly driven by the mission requirements and parts commonality with the P40. Keep in mind the P51 was designed as an alternative to building under license the P40.

[@allangibson2408]

The A-36 Apache was optimised for ground attack. The P-51A was more of a what can we get right now (as the British were uncertain about Merlin availability (hence the Bristol Hercules radial engines Lancaster at the same time)).

[@JohnRodriguesPhotographer]

@@allangibson2408 the a-36 Apache came after the P-51. The a-36 was built to US Army Air corps specifications. The P-51 was built to RAF specifications. It was in fact designed as an alternative to the p40. North American aviation did not want a license build another airplane company's aircraft. They offered the British RAF purchasing commission to design and build a totally new aircraft that would be better resulting in the P-51. Note the P-51 is equipped with the same engine as the p40 at that time. The Merlin wasn't even a part of the equation.

[@tomhutchins7495]

Speaking of iconic matchups, I would be very interested in good information on the Hurricane. I suspect we have been poorly served by both documentary makers and game developers in favour of the Spitfire. Actually I would welcome any videos you care to make on any of the aircraft mentioned: they are always thoughtful, exceptionally researched and fascinating.

[@GregsAirplanesandAutomobiles]

Certain British airplanes are horribly under represented in history, the Hurricane is one of them, another is the Bristol Beaufighter. I'll see what I can do about this.

[@sadwingsraging3044]

@@GregsAirplanesandAutomobiles Hurricane is the obvious winner in least represented to largest contribution during the war scale by far. The Typhoon Vultee Vanguard in CBI theater is *_never_* talked about! Vultee in any regard for that matter. Italian planes and *_engines_*

[@francisbusa1074]

I was born right after my dad came home from the Navy in WW II. When I was six years old he got me a model of an F6F Hellcat for Christmas, and helped me build it. He loved that plane, especially after the First Battle of the Philippine Sea in '44 (the Great Turkey Shoot).

[@anels9]

I absolutely love your videos Greg, you do a huge amount of research and proper research. You don’t have a biased opinion and you always look at things from a factual point of view. You clearly have decent mechanical knowledge and aren’t just reciting something you’ve read. Your aviation videos are the best. I have so much more appreciation for just how good some of these warbirds truly were in such difficult conditions and circumstances

[@donb1183]

As a Detroiter I loved the Jam Handy shout out. Their old building is still used for various exhibitions and some performances. Was in there a few years ago. Still in good shape. Sadly the Packard plant still mostly stands but was abandoned in the 1950s when Packard merged with Studebaker. It is in very sad condition and supposedly is to be demolished this year.

[@anthonywilson4873]

The beauty of using a turbo for the first stage of two stage supercharging as used by the US is as the air gets thinner the turbo spins faster as the the air it is pumping is less dense with less resistance, so this compensates automatically to a certain affect the loss of density. The second stage mechanically driven supercharger see’s the same density of air due to the faster spinning turbo and could maintain its boost step to a lot higher altitude. Agree the Rolls Royce developed Two Stage two speed supercharger with intercooler and aftercooler was a marvel of packaging. The intercooler/aftercooler rad was in a duct under the wing. When the butcher bird came out the Spit V was at a disadvantage with regards to power, that’s when two stage two speed supercharger was developed by Rolls Royce, it was needed. That was after the Battle of Britain. Then of course later the Griffin was developed into the Spitfire to maintain the gap. MK 1 and 11 Spits fought in the Battle of Britain. See here flyaspitfire.com/battle-of-britain-2. And of course Wikipedia en.m.wikipedia.org/wiki/Aircraft_of_the_Battle_of_Britain. The Spitfire 1 and 11 where a good match for the BF 109 and no FW 190 yet.

[@nexpro6118]

So sad how the merlin used a carburetor. Ugh, gross. Lol like, you dive too steep, maneuver rapidly/quickly, than you chock the carburetor of fuel.....so dumb. Fly too high, you can freeze the fuel in the carburetor walls. Fuel gets too hot, you can have vapor lock. Not to mention, it's bad in fuel efficiency compared to the fuel injection. Also, if the fighter had water injection, then how would you change the fuel mixture rate to better Mix the extra air with extra fuel.....

[@TheJustinJ]

The Spitfire was a model of simplicity and elegance. And it decimated the best air force in the world when flown by 20 year olds with 300hrs of total time, 30 or less in type. So, I don't think lamenting a carburetors minor drawbacks is warranted. There were some obscenely fast Top Fuel and NASCARs running Carbs until just a couple years ago.

[@daveschwi3767]

Really good stuff as always! I am never short on amazement when I think about how all this technical advancement was accomplished without sophisticated computers, CAD/CAM, FEA etc. and in relatively short time. Then add the pressure of a world war.

[@markwilliams2620]

Apollo got to the moon and back on mostly slide rules and pencils. It is amazing

[@thomaszhang3101]

I remember in your Bf109 video that you will do D9 vs P-51d one day. Finally!

[@GregsAirplanesandAutomobiles]

Oh, your remembered that, well done!

[@phil3114]

Mate, instead of monetizing youtube you should write a book. Especially comparisons like these are highly fascinating and would make a good look in every book shelve

[@GregsAirplanesandAutomobiles]

Hi Phil, I'm not sure how that would work. Should I stop making videos for a while and write a book? I don't have time for both.

[@phil3114]

@@GregsAirplanesandAutomobiles "if", and I write "if" intentionally, money is your priority then this is exactly what I would do. There are raging and ever returning debates going on in the military interested community, especially when it comes to simulations, who wage almost all out war when it comes to praising or dissing their own/other nation's gear and vehicles and whatever. A thouroughly researched book based not on hearsay but primary sources from an author with an inherently good understanding for mechanics and the ability to explain it in a few simple words, covering the range of typical ww1 and/or ww2 aircraft would do rather well I believe. Especially if it promises to tackle the most typical myths out there.

[@AdurianJ]

US Army Air Force in the 1930's: "Yo Dawg i heard you like superchargers......."

[@kenanfurcle786]

@Garrison Nichols wow man you really have a great sense of humor

[@clementfabre5860]

Picturing Doolittle with bling jewelry and a basketball jersey...

[@Rayan-bj8wn]

"so we'll get you a supercharger... then a supercharger for your supercharger"

[@seanmac1793]

@Garrison Nichols Wooosh

[@mcmoose64]

Great to find a channel that doesn't just regurgitate Wikipedia pages , baseless myths , wartime propaganda , and old wives tales. I am in my late 50s and have been a fan of military aviation literally since pre-school , when my dad gave me a picture book of combat aircraft through out history . It probably helped that every picture had Snoopy peering out from one of the crew stations . From age 6 , I devoured every book and article on the topic of military aircraft that I could find in my local and school library. Almost every cent I earned during my childhood and adolescence went into either model kits or reference books. This continued until I discovered girls , motorcycles , and eventually beer. I thought I was pretty well informed , but your insights and technical analysis has been truly eye opening . This is one of the few channels that I watch religiously .Keep up the great work .

[@GregsAirplanesandAutomobiles]

Thanks Anthony.

[@chuckschillingvideos]

I think it all comes down to the pilot and the specifics of the situation. Each plane has certain situational advantages which can be utilized against the other by a skilled pilot. Either way, two of the loveliest combat aircraft to ever grace the sky.

[@SquillyMon]

One of the deciding factors in restoring my 67' MGB was British Whitworth Standard. I became aware of Whitworth's existence directly due to this vehicle and it played a major role in my decision not to deal with it and to subsequently give the car to my brother. Today the MG is beautifully restored and resides in Colorado. I lost my brand new car dolly in that transaction as well...lol. I've heard from other sources that "Metwrench" tools work quite well on BWS.

[@jaredneaves7007]

I'm a simple man, I see a Greg video I click play.

[@blacksheep5466]

Ya I'm 30 an industrial electrician and millwright and I love this channel. It's amazing to listen to someone who knows so much on the topic... an actual expert...

[@GregsAirplanesandAutomobiles]

I'm working on an electrical video you will probably like.

[@dougdenhamlouie]

On may 31 1944 my dads group was jumped from behind by FW190D led element. They were attacked from above and behind killing the 333s leader who my dad was flying wingman to. My dads P51bc caught up to and disabled the FW190D in a full power dive. As my dad flew over the german broke into my dads wingtip. 2 whole months in a Romanian POW camp and he was back home as a flight instructor flying P47N 5 days a week. Heaven I say. Texas gunsmith

[@marinandrei1679]

Cool story but when did Fw190D's flew in Romania?

[@dougdenhamlouie]

@@marinandrei1679 Some real heavy hitters were moved to Romania spring 1944. Gunther Rall 275 victories started in Romania 1941 then finished in 1944 flying the 190D. If you want to question someone who has read EVERYTHING on the Romanian air war you had better have your shit wired tightly or someone like me is going to ass rip you. This May 31 battle is covered in detail in the 333s newspaper of june 1944.

[@marinandrei1679]

@@dougdenhamlouie the Fw190D entered service in September 1944, Günther Rall flew the Fw190A Im not saying you're dad didn't flew above Romania Im asking about the Fw190D Also as a Romanian my self, i know my history better and others, i accept the US Airforce bombed Romania , but Fw190D above Romania? Idk after we switched sides in 24 August 1944, we captured only A3's and A5's

[@dougdenhamlouie]

@@marinandrei1679 The D was not a common frontline aircraft for the most part late war. The need for high octane fuel was a issue late war. And when it entered service is in question. Go on Wikipedia and no telling what you will find. Some say early 45 it entered service. Not true. Many of the hotrod D model were given to group leaders or VIP pilots like Gunther Rall. I am selling a house and moving to New Mexico and much is already packed up but have some proof of my claim. Would need to scan that part of the book Polesti and the 333 news paper? As well since my dads wing tip sliced through the cockpit he got a real up close look at the plane. A FW190D. As well his first hits in the dogfight blew the radiators on the 190D. The radial equipped 190s did not have radiators. BTW as a baby I was held by your Princess Catherine when she was a guest in our house. Got a picture of her holding me in 1963. She fled Romania post war and ended up in Comfort TX i think? i still have her book somewhere? My dad was POW in camp 17 a converted boys school. Do you know of it? They say it is still there? I still have the red cross POW post cards from that camp? I have been trying to identify that pilot and plane for many years. If I can identify the plane likely I will identify the pilot as the plane was so uncommon?

[@dougdenhamlouie]

@@marinandrei1679 I have a German historian looking into who was killed on that day May 31 1844. I will save your post and send you what I get if your interested?

[@thomaspinney4020]

Jam Handy - Been a long time since I heard those. The lessons were really effective. They remain a good learing tool, especially for technical subjects. Thanks for showing them.

[@julianneale6128]

Another excellent legendary example to put up against the D9 is the Spitfire MkXIV, as it's a development from the earlier MkVIII with a different engine. An absolute beast of a machine combining outright performance along with fantastic maneuverability.

[@rodparsons6719]

Tempest 2 or Spit XIV in the winter/spring of '44/'45 in the British sector? Or if we're playing fantasy football then the Mk.24 against the D13?

[@erichammond9308]

thanks for keeping it real! the Merlin and P-51 collaboration was truly a joint endeavor and credit to both sides is well deserved!

[@juanpablorossicabrales9176]

Great!, Could You do video duel between Bf 109 K versus Spitfire Griffon.

[@GregsAirplanesandAutomobiles]

I really should do that.

[@apfelsnutz]

What a SUPER ANYALISIS thanks very much, I've always loved the FW-190... since I saw the one sitting outside at Santa Barbara apt. in the '60s and '70s. It was a D-9, strangely disappearing by the mid '70s. I never really liked the P-51, but favored the P-40 for the stalwart that it was. All the Best,...

[@FiveCentsPlease]

+apefelsnutz The surviving Fw-190D-13 went through a couple of owners in the late 1960s before it was bought by Doug Champlin. That is what you saw because it spent some time sitting outside in California. This was also when the owners at that time stripped off all of the original paint to apply zinc chromate paint and erased much of the identity of the aircraft for some time. live.staticflickr.com/5081/5338427400_85387a631f_b.jpg Doug Champlin shipped it to Germany in the 1970s for the first rebuild. It was rebuild again to better condition sometime around 2001.

[@stevejennings1373]

Thankyou again Greg for your excellent presentation on this subject. I especially appreciate your logical analysis on the vague or grey areas in the discussion. By the comments, I enjoy the contributions by sharp people who enjoy these subjects as I do. Many thanks to all.

[@Mike-eq4ky]

The fuel aspect and its effect both on the war and aircraft development is really intriguing (and Greg's video on WWII's fuels is essential viewing) and was such an important strategic element of the war, very often not fully appreciated. Arguably, the Germans launched the war partially over oil, and the impact of their lower octane fuels on powerplant and aircraft development is fascinating. It was made real for me as I was waiting on line at Duxford (in the UK) to get into the Imperial War Museum and was chatting with an older gentleman who was part of the US or UK (can't remember which...) aircraft evaluation units who'd flown virtually all the fighter aircraft on the Allied and Axis sides and said, "if the Germans would have had our fuel, we'd have been in for a very rough time". They'd take a 109 or 190 and put our 130/150 octane fuel and test them and the results apparently were eye opening. In this video, Greg's comment about being able to get an additional 25mph or so in top speed by going from the 87/89 octane fuel vs the US / British 130 was the best example of practical impact. Very enlightening indeed!

[@rob.heinlein]

FYI, the "Nur für den Dienstgebrauch" on your Fw190 manual is a security classification and translates to something like "for internal use only". Fascinating stuff, as always, Greg!

[@GregsAirplanesandAutomobiles]

Thanks Rob.

[@timelwell7002]

Greg's in-depth knowledge of factors such as engineering and aircraft design are very impressive - which makes all his videos far more informative than most (or possibly all) other similar channels. Keep up the good work Greg..!

[@charlesflint9048]

I am always seriously impressed by Greg’s presentations. I’ve found the driest technical descriptions very engaging to follow, he makes complex stuff understandable.

[@neoconshooter]

I used to go to the Museum of the USAF two or three times a year and would spend one, or one and a half days crawling through the plane displays and 2-1/2 to three days ensconced in the records rooms. While there, I talked to all the old pilots and photocopied the relevant flight data pages from the manuals. ( I was designing a Game that resembled "The speed of HEAT" at the time and wanted to be accurate!) Both the old pilots and the manuals show 80" of boost on 150 Octane Gas and 437 MPH for the "D" and 440 MPH for the "B/C" models. (More wind shield pressure drag and less pressure recovery drag for the B/C and less Wind Shield drag and more Pressure Recovery Drag For the "D" equals 3 MPH more speed for the B/C than the D! But the "H" had less Windshield Drag and less Pressure recovery Drag from the redesigned canopy!) In addition, they also showed much higher levels of boost giving 2,218 HP with ADI in the -9 Packard Merlin used in both the P51H and P-82 A/B, but 2,300 HP in the late Allison's, but at less boost than required for the Merlin to get the 2,218 HP. I asked why this was and was told it was because the Allison had better heads and "Pent roof" Combustion chambers like the Myer-Drake Offenhauser Indy Car engines. Do you have any ideas about these things? Sincerely, Stewart. PS love and subscribe to your channel for a long time and hope for a P-38 series soon?

[@The7humpwump]

Great video, thanks. I hear your wife likes the P-38...you should make her happy and do a video on that.

[@GregsAirplanesandAutomobiles]

LOL, thanks for that.

[@The7humpwump]

I’ve got your 6

[@Cheka__]

@@GregsAirplanesandAutomobiles Yeah, make all of us... um, I mean her, happy.

[@genuinsanity]

Amazing .....the details....the little differences make a HUGE difference !

[@LEGOBubuS]

Yesss.. 😃 Greg is back with another super quality content. My Monday is saved!

[@exsappermadman25055]

I don't have an hour dude but I get the jist. The Allison engine made the plane faster but the compromise between that and the Merlin meant that the Merlin was the better choice. The lack of fuel injection on the Merlin was a problem when going inverted but luckily they didn't have to do that very often as both the Mustang and Spitfire could out turn the German opposition. You make a really good point here about how the planes were built, as in the conditions. British factories were being bombed too until we moved them and passed on fake info as to where they where....Nice channel man, subbed.....

[@jroch41]

Another super-informative video from Greg about a relatively little known German fighter.

[@321-Gone]

The difference between combustion and detonation is easy to understand. There are 2 action in both combustion and detonation. The pressure wave and the flame wave. The flame wave travels at the speed of sound. Detonation is a bomb. The pressure wave is traveling faster than the speed of the flame wave. Where the flame wave is mostly a pushing expansion of energy. The detonation is like a steel hammer and will easily damage a softer metal. Usually an aluminum piston or cylinder head. It's alwasy important to understand pressure creates heat without a flame. Allot of heat. (Side note, that's why a turbine supercharger needs a charger cooler. Not because of heat transfer through the turbocharger body.)

[@theccpisaparasite8813]

It would have been interesting to compare the FW-190 made with high quality metal and Allied quality fuel.

[@paulmryglod4802]

My opinion is that with allied manufacturing and fuel, the 190 would have been a superior plane, especially with allied abilities to improve quickly.

[@danmallery9142]

Oh man, you brought back some memories with the filmstrip "movies"! Yes, being the filmstrip advancer was a badge of honor in the early grades. Not so much in the middle school or later years.

[@GregsAirplanesandAutomobiles]

It was only one step from being a hall monitor.

[@1QU1CK1]

I can still hear the little beep meaning "next".

[@alexanderrswaim5142]

I can remember a handful of filmstrip projectors with an integrated cassette deck that would _automatically_ advance at the beep (which I think was filtered out of the speaker). At the time that seemed pretty amazing.

[@11bravocrunchie22]

Once again, excellent work, Greg. I love how you break the details down to where someone who doesnt know much about airplanes can understand the topic.

[@shawnmulberry774]

as a 50-something I can tell you how much fun it was to have you discuss Jam Handy. Also, thanks to those old school "myth busters" with giant mallet - lol I bet the narration and background music was quite enjoyable.

[@Philistine47]

_"Don't ask me how this wasn't a violation of the Neutrality Act..."_ Yeah, don't ask the Roosevelt Administration that, either.

[@paythepiper6283]

2 World wars and on both the USA sold weapons in huge amounts, long before they joined the conflicts. Draw from that what you will

[@seanmac1793]

We don't pick sides but just want one side in particular to win

[@wkelly3053]

Some actions regarding U.S. aid taken back then, though uncomfortably done with arguably marginal or (yes) no legitimate authority, nevertheless demonstrated by the end of the conflict to have been beneficial to preventing a Nazi dominated Europe, and it also made for an easier U.S effort once we finally woke up and realized it wasn't going to end well if we failed to get involved, officially that is. I personally cannot imagine the impossible task that would have been thrust upon the United Sates if the British Isles had been overrun. Of course, if that wouldn't have been a problem for you, or your interest is generally counter to the historical end result, then you are welcome to roll your dice and forever debate the proper parliamentary procedure for the sake of absolute correctness while the fire licks at your doorstep. People who are theoretical ideologues may have a hard time appreciating "time threat" and "no-time threat" protocols that many who work in the real world are taught to use every day. In a "time threat" there is wiggle room for planning before acting, but in a "no-time threat" the objective is to act before control is lost to the point that discussion becomes academic. Those of us who do our jobs based on these strategies are actually taught that one of the traps that will make failure more likely is thinking that gathering more information is always better, when in reality it can cause a paralysis from action that is far worse. Yes, there really are situations like that in world affairs, as bitter as it may be for some to accept.

[@anthonywilson4873]

Good job they did, do you think Japan attacked Pearl Harbour without declaring war was fair. It’s War it’s dirty, look around you now, any clean wars? following all the rules? If Uk had not survived no place to land in Europe. US would have been on its own. With Germany and all the Axis powers to oppose. They would not have forced US into submission never. US would not have been prepared. Lend lease gets arms manufacturing going without saying you are preparing.

[@wotnograpefruit]

November 5, 1939, FDR signed the so called "Cash and Carry" act. If a belligerent power paid in US dollars and moved its purchase in its own ships, it could buy whatever it wanted from the United States. In practice, this ended the arms embargo of the Neutrality Act. Of course, belligerent countries were still forbidden from taking out loans in the United States, so broader issues of finance were still an issue, but the messy politics of Lend-Lease belong properly to a separate video.

[@13aceofspades13]

Another well put together video. You know I told Bismark this, but I really appreciate you guys, when you guys make videos you present the facts and don't present some biased dog and pony show that is put together with poorly acquired info and no sources, you show the bigger picture. I always laughed at the "The D-9 is better because it's faster." people, but as you have clearly shown on that graph it entirely depends on altitude and conditions what determines who is faster, and the truth is both planes are very close to one another, but the D-9 nor the Mustang are faster all the time, it largely depends on the conditions of the aircraft, their pilots ability to fly the aircraft, and the conditions they happen to be in.

[@dominicanbikinibeauties6537]

The Focke-Wulf was built here in Bremen, Germany home of the famous Becks Beer. Nowadays, approximately 2,500 people work at the modern second-largest Airbus Commercial site in Germany exactly where the FW 190 was assembled during Hitler time.

[@GregsAirplanesandAutomobiles]

That's really nice to know, thanks.

[@Wookie120]

Glad to see someone who gave the Albatross and the Hurricane the credit they so well deserved! Good job brother!!

[@DefendUSA1776]

Walmart Greeter Greg: "If you compare the Bf 109 to the Yak 1..." "Dude, I just need to get milk!"

[@GregsAirplanesandAutomobiles]

I don't think Walmart would hire me.

[@stevethomas760]

@@GregsAirplanesandAutomobiles Don't know you but I'm thinking you're a "I said take a cart" kind of guy

[@Mjr._Kong]

For some reason, the BMW 635 reminds me a bit of the Dora, in profile anyway. Those Chermans sure know how to design beautiful functionality!!

[@peterbellini6102]

Amen Major. I had a very late model '89 BMW 635CSi, very hot car and yes....

[@minimax9452]

„startleistung“ means „Take-off-power“ and „Notleistung“ means emergency power. All the best from Germany

[@groomlake51]

It’s crazy how little compression they ran even with forced induction. I would of thought that more squeeze would help at altitude. I live at 6,200’ in Lake Tahoe. Most all of the High Performance street engines I build for local guys have 1.5 to 2 points more static Comp than a engine i would build for sea level. I can’t help but think the open chamber style combustion chambers back then was a disservice to combat Knock. The modern trend towards the closed chamber design with a good and tight quench. Has really allowed engines to live @ much higher compression numbers with lower octane pump gases. By reducing chamber volumes and getting the piston to head clearance @ the quench to with in .040” to .030”. Has allowed guys to run up to 13.5:1 on 91 octane fuels with very little risk of preignition or detonation by there not being any room for a second flame front propagation because there’s no room. I have also seen positive results using the “Somander Singh Grooves”. They seem to allow you to retard ignition timing back closer to zero while still making the same peek power thus increasing efficiency via less resistance due to ignition lead.

[@Mike-eq4ky]

Great thoughts and info, but we have the benefit of hindsight and all the work that was done back then to get us to this point. I think most of the knowledge was there but I suspect there are numerous reasons for the low compression designs. Chief amongst them was probably reliability rather than tuning for max performance. Aircraft engines also had to be manufactured with available production methods - they didn't have CAM production machinery available to manufacture to the high tolerance levels or the modern materials necessary to make them practical. They also didn't have electronic engine control systems to maximize the HP for a given displacement. There are economic factors and logistics to consider as well. These weren't designed to be race engines, but war fighting materiel with a completely different set of requirements. Some of the post-war work on Reno race planes shows what happens when you take these basic engines and start optimizing them for racing... of course, they only need to run an hour or two at those power levels before blowing up and no one is shooting at them...

[@TheJustinJ]

The answer lies in the piston/cylinder diameter. And the fact it has a steel barrel liner, and not aluminum. Both contribute to increased combustion chamber temperature, and therefore less knock resistance, therefore lower compression ratio. See "In theory and practice" by C.F. Taylor.

[@rayschoch5882]

Excellent as usual, Greg. That I am able to keep up is something of a tribute to your ability to translate complex engineering concepts and data into a form where someone (me) with zero engineering background can understand it. I'm also very impressed by the combination of physics and metallurgy involved in the engine mounts for the Merlin, and for the Dora's V-12 as well. Finally, I hope you'll briefly explain in some other video (or perhaps have done so already, in which case, where?) what's involved in WW 2 propeller design. American piston-engined fighters didn't begin to go to paddle-bladed props until right at the end of the war, and even then, it's pretty uncommon to see them in photos. The F6F and F4U-4 that my Dad flew in 1944-45 all had relatively narrow prop blades. German fighters, however, especially the FW-190, seem to have adopted the paddle-bladed prop much earlier. Why? What are the advantages / disadvantages of narrow vs. wide propeller blades? My limited observations have been that few modern planes, private or commercial, use props with that sort of wide blade.

[@GregsAirplanesandAutomobiles]

Hi Ray, I'll need to do an entire episode on WW2 propellers.

[@rayschoch5882]

@@GregsAirplanesandAutomobiles I'll look forward to it!

[@ASJC27]

Generally speaking, a "wide" blade (the technical term is high activity factor) will have better efficiency at low speeds but worse efficiency at higher speeds than a same diameter, same number of blades low activity factor ("narrow") prop. So a wide blade may provide a bit better maximal rate of climb and maximal sustained turn performance (both achieved at moderate speeds), but may have a bit worse cruise performance and top speed.

[@asiftalpur3758]

You have no idea how many times I'll be rewatching this. I'll leave a more detailed comment with questions and observations later, but you're really in your element here. Loved the energy! Can't wait for British comments and downvotes though lol. About time someone addressed the whole merlin issue/popularized myth of absolute and unchallenged British superiority without any context. Also, the whole concept of time doesn't apply to your videos, 1 hour rarely passes so quickly and here I am watching it for the second time.

[@crabbytemptations1771]

I'm 36 and you've made me feel young! Thank you!

[@vanteal]

We were still heavily using slide show films in the 80's and even 90's. It was a "treat" to be the student picked to work the button/knobs.

[@richardschaffer5588]

That was a lot better than running the movie projector! Threading the film through and getting everything right an education in itself!

[@smyrnamarauder1328]

I still wonder what could happen if Fw-190 fitted with BMW 801 TJ engines of ju-388 Ps.greg you improved your voice level on videos thank you for that :)

[@AdurianJ]

Ich bin geschwindigheit? 😁

[@smyrnamarauder1328]

Höhen Würger. (My german is not good)

[@Silverhks]

Yes he did up his voice level and it's fantastic.

[@DrJohn493]

I’m a ph.d. and I don’t understand all you’re describing/saying but I’m blown away by both the American and German engineering for that time period. And I’ve rebuilt automotive engines just for kicks. BTW I’m a pilot and have actually logged two hours in a TF-51 and find your narrative about the comparative aeronautical technologies attention grabbing. Also, both aircraft were works of art.

[@GregsAirplanesandAutomobiles]

I think they are works of art as well. However the artsy people tell me that something that's functional can't be art. Hmm.

[@FabioQuadrana]

I've always wondered why the Merlins were so powerful if they were relatively small compared with Daimler Benz an Jumo engines, and thanks to your channel I realized the huge factor that a superior fuel was over the engines performance, I didn't knew the differences were so dramatic. Germans not only had to fight with low availability of fuel, it also was low on quality and that impacted directly in the design of its engines. An ironic twist of fate was that the designer of the P51, Edgard Schmued, was a german...

[@givenfirstnamefamilyfirstn3935]

Sophisticated airflow control and supercharging and charge cooling and proficient metallurgy didn’t just appear by magic, the wërhäböö’s favourite _Master Race_ would have had to get all that right too!

[@errollemard6996]

I appreciate factualandand unbiased materials which are the fuel for knowledge and the preservatives of history. Thanks for taking the time to educate.

[@JordonBeal]

I just found your channel, and I gotta say, I love it. It brings me back to my childhood when all I cared about were WWII fighters, haha. Cheers, man. Great content.

[@Fastbikkel]

I like details, but under most circumstances i would not look into THIS much details. To be honest, i found it very enlightening and nice.

[@tommyvictorbuch6960]

When a video starts with the words "Greetings, this is Greg," you know you're in for a treat.

[@gort8203]

I also enjoyed the discussion of the multi-stage supercharging, to include mention of the great intercooling solution of the F4U. My understanding is that the Allison V-1710 could have had a 2nd stage supercharger if USAAF had been willing to fun development in the 1930s. USAAF was apparently betting on the GE turbine supercharger, even though getting them for the early P-38 and P-47 prototypes was like pulling teeth from a hen. I think a video comparing the BMEP of various engines would be a very interesting subject for your hard core viewers. I'm curious not only about which engines were superior, but whether there was a general difference between mono block and radial engines, for example.

[@GregsAirplanesandAutomobiles]

It might be interesting. BMEP is higher in the V-12s than in the radials. The Allsion did eventually get that second stage for the P-63 King Cobra, but it was too little too late, the switch to Merlins had already happened. Furthermore, it was a remote stage system like the Navy used, probably wouldn't fit in a Mustang.

[@martijn9568]

@@GregsAirplanesandAutomobiles Wasn't a similar Allison engine used on the F-82? Which would mean it would fit in an P-51H. Not sure about the original Mustangs

[@keithstudly6071]

@@martijn9568 Yes F-82 had Alison engines. I am told that there was a lot of redesign in the F-82, at least a lot more than it looks.

[@trn8061]

Amazing reasearch and in depth information.

[@Air-Striegler]

I was so greatful to see this pop up in my feed: "Greg´s got a new vid out....yeaaaah....!!"

[@PBODK]

Fascinating and interesting video, easy to follow for both aircraft mechanic me, and my girlfriend with no technical knowledge whatsoever. Keep up the good work Greg!

[@jimh6763]

Greg, I love all your videos, but im still waitin on the final p47 videos!!! My favorite fighter due to alot of the reasons you mention. Waiting patiently, Jim

[@GregsAirplanesandAutomobiles]

Thanks Jim, I'm working on Part 7 right now. Then Part 8, which will be easy to make, and it's done.

[@hangonsnoop]

@@GregsAirplanesandAutomobiles I'm very happy to hear this! I've learned so much from this series and all of your videos.

[@jimh6763]

@@GregsAirplanesandAutomobiles great Greg. Being an Auto technician for 30 years, I love all the technical stuff!! Fascinating!! Thanks again for all the research you do for these videos. Jim

[@johnm7611]

@@GregsAirplanesandAutomobiles any hints for what each of the episodes will be about

[@wazza33racer]

Dual stage compressors (superchargers or turbochargers) only work effectively when there is an intercooler heat exchanger between them. Otherwise the second stage is trying to compress very hot,thin air which negates most of its effort. Stanley Hooker covers this in his book, when he was part of the Rolls Royce effort to build two stage supercharging for the merlin. They essentially used a supercharger from the failed Vulture engine in tandem with the existing single stage merlin supercharger. They made the needed intercooler assembly, which Hooker stood on top of in his office to see if it was rugged, and it collapsed like a pancake under his weight....it worked out fine anyway. Hooker also said that the blowers sucking air/fuel mixture helped to drop temperatures and obtain excellent fuel mixing, and put it on par with the sophisticated german mechanical fuel injection, once they had overcome the negative g load problem.

[@GregsAirplanesandAutomobiles]

What WW2 two stage system doesn't have an intercooler? All the U.S. designs do. The British carbs were in no way comparable to fuel injection, which is THE reason all the Rolls Royce engines went to injection as soon as they could, which started around late 42'. That doesn't mean that carbs don't have some advantages here and there, but overall in terms of performance they are inferior.

[@wazza33racer]

@@GregsAirplanesandAutomobiles My comment was not meant to imply that US designs didnt use an intercooler. However, some diagrams and common beliefs among lay people, give the impression that one compressor can simply be channeled into another. For example, I was talking to a guy, that was racing trucks ( a Kenworth actually) and he had one turbo on his Cummins NTC directed directly into a second turbocharger, and said that his single,charge air aftercooler had temps above 200C and couldnt get it to make hp. I pointed out the Merlin example, and the guy had a big "I didnt think of that" moment. Regarding carbs on the Merlin versus the German mechanical fuel injection.........I was quoting what Stanley Hooker said in his book "not much of an engineer"....and given his level of experience in both the Merlin and later jets..........its an opinion worth considering. Even in racing cars, fuel injection does not give that much more power over a carb in w.o.t , dyno tests have demonstrated this. What injection does give is better performance at non w.o.t settings and in aircraft, gets rid of the negative g issue completely. Love the channel, keep up the great content!

[@lengray44]

Damn I have watched Jam Handy films in trade school in the early 80s. I always thought it was a play on words. You know, if you get in a jam this will be good to know.

[@randyallen2771]

What a nice surprise for Monday morning! Glad you're alive and well. Always happy to see a new program from you, especially if it's about 190s.

[@Holztransistor]

The Fw 190 D series always was my favorite plane since my grandmother bought me a model kit of that plane in the early 80s. Your videos provide a great deal of information. Thank you! There's only a minor "but" regarding audio quality. Might be due to the lack of insulating material on the walls like in an audio studio.

[@nickbaker4857]

@Hoa Tattis So....he should like those instead?

[@nickbaker4857]

@Hoa Tattis But if your favourite looking plane is a Dora then the Tempest is plug ugly so doesnt hold a candle

[@Waty8413]

The matchups most people think of are usually the assumed best-of-class for a specific point in time. Hence the spit vs 109 comparison instead of hurricanes vs 109, even though the hurricane was the the backbone of the RAF during the BoB and were used to great effect.

[@PaddyPatrone]

Shooting Pistons out of an engineblock is the most simple, but genius way to illustrate this subject. Learned a lot from This video. As always, keep up the good work Greg and I hope you have a nice day. Greetings from germany.

[@GregsAirplanesandAutomobiles]

Thanks Paddy. I watched your Dora 13 video a couple times before making this.

[@GregsAirplanesandAutomobiles]

I also think that shooting the pistons out of the block was very clever. I think that was the Rube Goldberg influence as the whole thing sort of reminds me of his cartoons. That whole episode is pretty good. It's called "Something for Nothing" and it's on youtube.

[@PaddyPatrone]

@@GregsAirplanesandAutomobiles Great to hear that. Would love to see and hear a flying D variant with Jumo 213. Something that hasn`t been seen or filmed ;) for many many years. Who knows, maybe some day.

[@GregsAirplanesandAutomobiles]

It's going to take one heck of a 3D printer, but yes, one day it will happen.

[@TreeTop1947]

I absolutely loved that clip! As soon as Greg said "Essentially they make a mortar out of an engine block", I was totally hooked. Semper Fi, TreeTop

[@christianbocker7842]

Hi Greg. You create excellent and highly detailed video. I fly air combat sims for almost 20 years now and I can still learn a lot here. Thank you very much for your effort. As I am German, I urge to correct one or two little things which is not easy to get as a native english speaker. Page 5 in the manual shown at timestamp 3:10 in your video isn't about ground attacks. The "Wurfgranate 42" was used as an air-to-air weapon! It was shot into large bomber formation, just hoping to hit something or at least damaging something. But it has nothing to do with air-to-ground rockets.

[@GregsAirplanesandAutomobiles]

Thanks, I try, but I have to deal with German, Japanese, Italian, and Russian language manuals, so mistakes slip through from time to time.

[@Jbroker404]

44:10 I was very surprised to hear this, as I've always heard that the bubble canopy adds significant drag, and that P-51 and P-47 razorback models were faster than their bubble canopy variants. I once heard that the P-47's bubble canopy took about 27 kph of the plane's top speed.

[@GregsAirplanesandAutomobiles]

I put the charts up at the end of the video. They are close, but the razor back is only a bit faster. In any case, I think it's fair to use it in the comparison.

[@devilsoffspring5519]

That's right--the bubble canopy increases drag. Even though the P-51D looks cooler, the older style straight-back fuselage type was actually the faster aircraft, by a few MPH.

[@SpinyNorman2]

@@devilsoffspring5519 By 3 mph (440 vs 437), but the D was heavier and had 6 reliable guns instead of 4 that tended to jam (because they were mounted at an angle).

[@devilsoffspring5519]

@@SpinyNorman2 In general, yes--the D version was the better airplane. More & better guns, better visibility, undoubtedly other improvements like better radio etc. The older one was certainly was faster though--by that little 3 MPH :) I'm pretty sure they used the same engine, V12 Merlin with ~18 pounds of boost, about 1700 HP or so.

[@dc3630]

Mr. Greg goes always in depth; clarification guaranteed! Thank you very much, Mr. Greg!

[@drstrangelove4998]

The Whitworth thread was good, and it’s interesting that Packard retained it. I heard that new, crated Packard Merlins shipped up to the UK with a Whitworth tool kit, which was much prized by RAF fitters, if they could grab it.

[@FiveCentsPlease]

+Dr Strangelove Every Merlin was shipped with a toolkit. www.surfacezero.com/g503/data/500/IMG_0064_Small_.JPG

[@drstrangelove4998]

@@FiveCentsPlease Indeed, that‘s right, thanks for the link!

[@seavee2000]

You make the very (VERY) valid observation that while P-51's were being made in peace,the production of any German aircraft by the latter stages of the war were "difficult" at best. Though suffering slightly less, England was bombed continuously (particularly aircraft factories) and the stress effect on the production workers in both countries should not be under estimated. And finally,the most important factor in ANY aircraft is the pilot-the US had many,well rested and fresh (comparatively) while the Germans had a few "experten" and some poorly trained pilots to put up. Even if the Fw had been 10 better it would have not changed the outcome. An excellent video on the technical aspects , I thoroughly enjoyed the balanced commentary and insights. Thank you.

[@JohnDoe-mx2kp]

6:08 Startleistung is takeoff power Leistungen im Nennbereich der bodeladerstufe refers to power in the designated range for the low stage supercharger. likewise the other line down below refers to the power for the designated range for high stage supercharger. great video so far, I'm gonna help with translation as the video goes on.

[@JohnDoe-mx2kp]

well not much left to translate Haha. btw, I have a huge compilation of original technical data for the db6xx v12 engines in Germa, if you need some information, hit me up.

[@malcolmmansfield7706]

Good to see you back!