33:39 Russian manual translates as follows: “While flying under 1500-2000m you can activate high power mode by pushing the throttle and the prop pitch lever to their foremost positions. The revs should stay at 2500 RPM, with boost being 1200mm of mercury. This mode can be used for no more than 15 minutes in one go. This high boost mode (1200 vs normal 1000mm of mercury) will allow the plane to go 30-35kmh faster. Typically, this mode can only be used after first 10 hours of motor time.” Second page: “80. At the second gear of supercharger the use of boost higher than 1000mm is forbidden due to detonation risks. 81. Engage the second gear of the supercharger at altitudes greater than 4000-4500m 82. Watch the gauges to avoid cylinder heads getting hotter than 240 degrees celsius and the incoming oil getting hotter than 85 degrees celsius” Great video, thank you Greg

I have a degree in combustion engine technology from Munich Technical University, been fascinated with WW2 aircraft engines as long as I can remember and yet I learn something new every time Greg uploads a video. Keep up the great work!

I have a full set of engine manuals from Buick for the P&W R1830s used in the B-24. My Grandpa took them home after the war and gave them to me in the 70s. The engine manuals are leather bound and are a work of art. the rebuild manuals are ring binders. Someday i will donate these to a museum probably.

The quality of this channel is mindboggling! Love the calm low voice as well. Absoulte joy to be an audience

I remember as a child, and I am 75 years old, that all but the newest automobiles were followed down the road by clouds of blue smoke. They all burned oil. Then, seemingly overnight, this changed. New ring materials and coatings came to the market. I’m guessing that as always these advances first came to aero engines thus explaining the change from four ring to three ring pistons. The extra ring was just an attempt to maintain compression longer when poor ring materials were used.

Thanks very much for this video. La-5F and La-5FN are two forgotten Soviet fighters that really were great performers, their wing configuration is pretty interesting too.

In 2000, I went to the Hannover Fair, bought the most expensive ticket so I could be there all day, as I was in the line, looked to my left, and saw an airplane on a elevated stand, A Hansa jet with forward swept wings I read Fluzeug Museum, any plan I had for that day dropped on the spot, walked that way, paid my fare, and had an empty museum for myself, what a joy! Walked about and a staff member asked me if I had any questions, delighted, I started asking a few in my broken English, the gentleman said, “please wait here” and went away, a few minutes later the museum director was walking with me answering all my questions, and somehow amused that a South American was so interested in airplanes, this was by FAR the best museum experience in my life. We naturally stopped at the FW190 A series, and the very fist feature it called my attention was the BMW 801 engine, it had an enamel logo in the bottom front cylinder! He explained it was recently completed, told me several stories as to how he found parts here and there, next to it was another 801 engine in a stand, He told me when the Soviets were taking anything of value right after the end of the war, this particular engine was in a cart pulled by oxen, something startled them while on a hill, the cart tilted, and the engine fell off and rolled down the hill and into a ditch, where it stayed a few decades, I could touch and examine the engine, what a moment … indescribable how every systems , tubes and rods occupy every single crevasse and available space within its volume, a memorable day indeed in my life to get to see engineering marvels after 20 yrs reading about it. A year later I went to the Smithsonian hangar at Dulles airport, and saw another FW190 in a recently open wing sponsored by Ford, the guide told the group he was addressing that this particular FW190 was restored to a 100% condition, in that moment I became that smart ass guy who told out loud “no, it is not, it’s missing the BMW logo in the cylinder #1, right at the bottom” and pointed with my finger. Years had passed, and every now and then I remember how unexpected fate took me to see my favourite airplane and engine in different places while not looking for it. Thank you Greg.

Thanks Greg. One thing that is enjoyable about your videos is the quality of the comments. You have a lot of intelligent, knowledgeable people coming here because of the intricate information being conveyed - and that is refreshing. One sad aspect of life in the USA - is that with the cut backs to High School Education and the change in the nature of automobile power plants future generations may not have the hands on practical experience we had growing up. It was common place here for teenage boys to take Auto Shop as a class in High School - and then the older engines that were not so computer controlled could be worked on by any one with an interest. In some communities such classes as Auto Shop and Music - were dropped because of a lack of funding. For me - having rebuilt engines and changed the rings - I could readily understand the discussions about them. I remember me and my brother in law rebuilding the engine on a Fiat where the cylinders were not all the same size - and so - having bought all the same size rings - for one of the cylinders - we could not get the piston back in with the new rings on it ... and had to buy some different sized rings ... In my generation - working on cars was just something that (almost) every young man did. Now ... because of insurance rates - there are young men who don't drive because they can't afford the insurance - and have their girl friends drive them about. My point about that historically was that during WWII - one of the advantages the Americans had - in fielding a military that had almost no animal transport - was all those young men who had grown up working on their or their buddies old Model T's and such that had been handed down to them. Because of that - you had a lot more young men with basic mechanical experience who were easier to train - but - you also had more than that. A lot of the crews of vehicles - would know how to fix them at least on a basic level and were not as dependent on Motor Vehicle Maintenance to do it . All of which would translate into more vehicles on the road and not in the shop. I don't know how all this will really translate into the capabilities of young men and the military in the future but I am concerned about it. .

Spoiled us again! I really appreciate looks at eastern front and pacific technologies as the wider audience might not even know the la5-5fn! BZ

We need a kickstarter "get Greg a good microphone"

My guess is that the transition from 3 to 2 compression rings was related to the introduction of chrome plated upper rings. Chrome rings improved sealing and dramatically improved ring life, so that engine designers realized they could switch to 2 compression rings and reduce drag while still maintaining good performance over the life of the engine.

Greg, since you weighed in on the overall mediocre quality of the Wright R-2600, and its unreliability (presumably just early till the kinks were ironed out) I think you might be interested in my father's perspective on Wright vs. P&W radials from his AAF/USAF career as a flight engineer at the end of WWII on C-47s through to his pilot days flying MANY radial-powered multi-engine aircraft from the early 50s through to his retirement in 1971. These included AT-6s, B-25s, C-45s, C-46s, C-47s, KB-29s, and KB-50s. (His last tour was flying C-141A's in 1969-71). Basically, he thought Wright engines were garbage compared to P&W engines. He considered them notable for short periods of serviceability between overhauls, often a fraction of P&W engines, and general unreliability. For the B-29's R-3350, he shocked me once by commenting that the engine only had a service life of about 100 hours between major overhauls, and when you got a B-29 with high hours on the engines, watch out! He described one incident in which a B-29 engine started to overheat so much that the cowling started to glow red and then a cylinder head blew off the barrel and exploded up right through the cowling! (Which isn't to say the R-4360s were fireproof. My father lost a close friend in a KB-50 when an engine caught fire and he stayed in the cockpit too late to save himself while everyone else bailed out. Anyway, my father was adamant that P&W made superior engines. Period. My personal comment is that by a twist of fate I worked as a corporate lawyer in the Curtiss-Wright Law Dept. from 1981 to 2001. When I started the Corp. HQ was in a huge, former R-3350 plant located in Wood-Ridge, NJ. Many areas of the plant had changed little from the WWII era. The corp. culture there was "not the best," and the history of the plant from the "glory days" of WWII wasn't the best, either. See "Building the B-29 (Smithsonian History of Aviation and Spaceflight) (1995, by VANDER MEULEN JACOB) which has a great chapter on the R-3350 and the Wood-Ridge plant in particular. Having said all this, there is one Wright engine that made a major contribution to WWII, and that might be worth a "review" by you to discuss why it was successful. I'd love to hear your thoughts about the R-1820.

Thanks for all your hard work in creating content and for posting it on here free of charge. I will never understand how anyone dislike content such as this. Another informative episode.

I think the main reason behind the drop in number of rings over the years is (among others), as you said, friction. Actually what happens over the years is that, in the quest for higher specific power outputs, engines increase their working rpm range and friction increases exponentially with speed. So the friction losses that are acceptable at one engine speed, become unacceptable at, say, double that engine speed. Also, at higer engine speeds, the loss of compression through ring blowby is less. So a high number of rings is now no longer required. More years go by... and now fuel economy becomes a thing, so now you have even less rings than before... and then anti-friction coatings on the piston skirts, and then you go to no piston skirts at all.

Did not know that about the Packard Merlins. I'd imagine that finding hardware in the modern era to keep them running must be challenging. Interesting as always.

Loved it will rewatch multiple times.

Another great video. It is refreshing to have technical videos that are informative, not 10 minutes of fluff. Almost like mini grad school lectures. As a former USN submarine officer I really enjoy history not being dumbed down.

In professional aviation and in engineering in the US, I've used exclusively Celsius. Too many people think the US doesn't know how to use metric. In my engineering job we also seamlessly work in imperial and metric units. Units of measure are just a matter of preference and perspective. the units used to measure something has no bearing on how high quality the end product is.

Well done, as usual, Greg. Those of us who are not engineers continue to enjoy your talent for reducing what could be brain-numbing complexity to something understandable to the non-specialist. I'm also finding, at least in this case, that it really does help to be something of an automotive enthusiast, as well. All those Hot Rod and Road & Track Magazine articles I read decades ago about automotive engine performance have turned out to be surprisingly useful, in this instance and others, when talking about aircraft engine performance. I look forward to Part II.

The biggest weakness of the La-5 is all of the things that you have to control manually. New pilots simply wouldn't get the most out of the aircraft in a dogfight because there was just far too much going on, and all of the engine system controls weren't down as perfect reflexes.

German native speaker here and I've been interested in WW2 aviation since I was a kid .... but trying to read that excerpt from the 190 manual explaining the C3-system kinda made my head spin. Talk about engineers needing to polish their communication skills. And I'm not sure this is due to the period the text was written in - I'm pretty sure you'd still find technical manuals to this day that would sound very similar in tone. This is almost like something out of a sketch making fun of what we call "Fachchinesisch" - meaning technical jargon or, more literally "professional Chinese". :D

Thanks Greg. You have the ability to make the mundane spectacularly interesting.

Thank you, Greg - your videos are a Masters-level education on my favorite technical subject - Warbirds!

Thanks for another great video! If I remember correct the Chinese still manufactures a copy of the Ash.82 engine, and that engine is what usually powers the few airworthy FW190:s that still exists (except for Paul Allens, where they managed to restore the original BMW 801). Really looking forward to next video with the advanced engine management system (the Kommandogerät!). Would love to hear your view, as a pilot, on it's effect on pilot work load - especially during combat/dog fights.

2:07 "Loosen the airscrew nut" it says. Preferably during your morning coffee, as the dude looks like he is in his comfy robe. I love these illustrations. Like, realistically, they would have to show three guys in tank tops leaning on the breaker bar, instead, we get bespectacled gentleman in his 60s, gently prying on the nut.

A Do 335 with two DB603, nice. I am stealing that idea for my HoI4 Kaiserreich headcanon writing stuff. Anyway, thank you for another great video Greg, your content is the best ww2 aircraft stuff on youtube. Anyway, have a nice day Greg, and greetings from germany :) Edit: spelling, it's hard :P

Will watch that tonight with great interest. And thats an understatement. Thanks Greg.

Another excellent presentation from Greg. Can't believe how quickly that 40 minutes went by! 👍

Definitely Worth the money to see it a day early

I have been curious about Soviet engine performance and all my questions have been answered. Well done Sir! ✈

Can’t wait for you to cover the brilliant sleeve valve engines. Napier Sabre was absolutely incredible

Facinating Greg. As usual your info in interesting and technical. Your delivery is terrific

Very interesting video. Glad you mentioned the "engine control system" because the Kommando Geraet was the really novel feature of the BMW 801, and has been referred to as the world's first ECU. Did the 801 TJ (turbo-supercharged) ever enter service?

These videos go way too fast. I'm like there's no way that was whatever time was indicated. The best content, analysis and context. Always hungry for more.! Thanks Greg.

Awesome! Thanks for another superb video, Greg! Love your hard work!

4 ring pistons were still very common in heavy duty/industrial gas engines into the 90s. The 366/427 tall deck truck engines from Chevrolet are an example.

Thank you Greg, another fascinating video!

I will take your questions regarding the C-3 inj. to Flugwerft Oberschleißheim at the end of September. There will either be answers or free tickets to the Ostfront

Again excellent video! 30:37-30:44 another reason why this is not a substantial advantage is because to sortie duration on the eastern front was, on average, between 55-65 minutes leaving roughly only half of that time max for fighting (25-30 mins). This is within the time envelope you bring up.

Thanks Greg! Another fascinating video! =)

Another awesome video Greg. Cheers!

Greg this is awesome, thank you for your hard work. It would be super cool to hear what you can learn/know about the Napier Sabre

A great video indeed. All of the described engines deserved a detailed insight.

About time we got a good comparison of these 3 cousins, the Wright Twin Cyclone 2600, the BMW 801, & the Ash 82

Awesome stuff Greg!

Very well done and a whole boat load of info. This ( in the written book form) really would be a wonderful addition to any FW-190A -5 flight, maint., and other pertinent written manuals that are required for the operation of that aircraft.

real nice that given a talk about X, the speaker fits also a lot of related interesting topics, like the supercharger gap.

I think "ash 82" is close enough)). I think we'd say "asha 82". (The letter Ш is called sha, and it gives a sh sound.)

Piston speed is not the real problem, it's piston acceleration. When pistons accelerate too quickly the rings lose their seal in their grooves (ring lands). This causes a loss of power, and accelerates wear in the ring lands. Eventually causing a piston ring failure.

Hey Greg, another well researched and well presented topic on something I didn't know I'd be interested in... but still watched the whole video and enjoyed all of it. Also, I'd NEVER heard of BSW or that every Merlin, US or Brit uses that standard. Awesome.

Thanks for a very good and informative video! I would love to see a video (or even a video series) on the La-5, La-5FN and La-7. The La-7 is coming for DCS in the future, and I would love to learn more about it.

Great analysis and information Greg. Thank you.

Many you are making some well interesting videos for us WWII Geeks!

Thanks again Greg, wonderful series. Are you planning to get back to sleeve valve radials and the Beaufighter, or maybe the Sea Fury or Tempest?

Thank you for not killing my ears with "Ay-esS-Haitch 82". You overseeded 99% of your countrymen.

One small correction that the DB-603 engines did see combat in Me-410 aircraft. Kurt Tank really wanted to use the DB series in his aircraft but they were not available. After WW2, France was left with two He-274 prototype aircraft and used them for high altitude research, so DB-603 engines soldiered on in the He-274 aircraft until the early 1950s.

Great video as usual!

Interesting. In War Thunder the A-5 only runs 1.42ata but the performance changes exactly like in Greg’s Chart for the C3 injection. So above 1km the performance continuously drops till at around 2.5km, where it immediately jumps back to 1.42. So it behaves like having C3 injection without the boost in performance.

Love learning about these engines, bloody marvellous!

I saw an Fw-190 flying over the D-Day memorial and later as a static display at NAS Oceana. That particular plane was actually a replica made by Flugwerk, and was powered by an Ash-82 rather than a BMW-801.

Greg and his channel are awesome as always!! I think the pic of the BMW 801 pistons show *4* compression and 1 oil ring, not *3* and 1. Thanks as always!

being an engineer in those times... man... there was so much to research and improve on... putting aside the crap, the engineering in all countries was incredible...hats off to those smart minds !!

Whitworth (BSW) is the course thread in imperial units used in the UK, while BSF is for most uses in engineering. BA is a numbered metric series for threads under 0.25 inches diameter often found in instrumentation and electrical equipment. The likelihood is that any UK produced engine will have used all types. BSW was the first standardised thread and BSF followed and shared the cutter angle of 55 degrees, where UNF and UNC would be 60 degrees, and I can see that they could be seen as both Whitworth. BA thread standard is 47.5 degrees and has a relatively shorter thicker thread profile that suits the production and strength of smaller components and BA screw threads are mostly produced rolling rather than cutting.

Good video, Greg. Some versions of the Dornier Do-17 / Do-217 family used BMW801C engines. That's not much use for comparisons with the FW-190 which used the 801D version after Feb 1942, but it might be comparable to US use of the R2600 in the A20. Anyway, one of your better videos. Thanks again for the good content.

Thanks a lot; as always , interesting and clear

[Ash] is a pretty good pronunciation, as it is designer's full name "arkAdy SHvetsOv", where "Sh" is a single Cyrillic letter "Ш". The better could be only "Aa-sha" (probably) from alphabetic names of these letters. But I cannot be sure about the era pronunciation of this abbreviation. Written as АШ-82, АШ-82Ф, АШ-82ФН (F, FN respectively). Don't forget BorIs ShpitAlny and SemiOn VladImirov authors of ShVAK (Sh-V-A-K) 20mm cannons of La-5...7, ШВАК.

Nice work, thanks.

Great episode again.

Great video again really interesting

Hi Greg. Awesome video (again)! Regarding 801 Cylinder head assy. Like you say, likely heat shrunk on. I believe the heads were threaded on to the circular top end of the steel cylinders, in a heat/ shrunk assembly process. So in essence a threaded heat-shrink mount. Common pre war radial practice it seems. I found a detail section drawing showing a threaded interface. BMW usually designed for easy service, so this seems likely.

Been reading R-2800 Pratt & Whitney's Dependable Masterpiece (SAE R-241). Apparently P&W had designed a 2600 cubic inch radial around the time of the Wright Twin Cyclone, but their Engineering Manager basically said, "Nope, not big enough. Make it bigger." They shelved their 2600 c" design, went back to the drawing board, and produced the R-2800. On that note, I've also discovered that the SAE has a lot of their engine books for sale in ebook format. Not cheap, but definitely portable.

Love this info. Thank You

I believe part of the reasoning for the shorter stroke was for mass production or spare parts, if you have a given amount of metal you can produce a bit more short connecting rods rather than longer ones.

I have the grand slam of tool set requirements. I've got a transition MOPAR when the Diamler Merger was starting to effect manufacturing specs. It has the annoying quirk of both ASE & MM fasteners (sometimes on the same module). Then I have a 1917 Remington built Mosin Nagant 1891, and it not only uses Russian specific fastener designs but sighted in units of Arshins/cubits and nobody agrees on the exact conversion to Imperial or Metric. If you need to get a fastener for the rifle, better hope an old Russian Civil Guard happens to have some spares laying around.

Nice tech video. Thanks.

It's clear that bmw 801 has 5 piston rings with one at the very bottom of the piston... Cause i am a mechanic and see that also on agricultural machinery many companies want to put 2 piston rings on a pistons and many now put 3 piston rings... It's a tough balance of more piston rings meaning low tension rings so lower compression but also more friction meaning less rpm and horsepower... Less piston rings mean more hard material but less friction, more prone to scratch the cylinder around the piston, if a failure to one ring happens means greater need to change it, not so robust and prone to more oil consumption...

I could probably get you some clearer pictures of the 801, also of some of the internals. It's from a crashed Fw190A8, so the engine is completely wrecked and has subsequently spent 50+ years underground. The guy also has a couple 109 engines in various stages of decay, but you can still make out all the interesting bits like the superchargers.

5:54 That's a BV222 flying boat. There's one in perfect condition in a Norwegian fjord having been scuttled at the end of the war! There are (or were) plans to bring it up but it'll cost a fortune

It cut down on the drag in each cylinder. My Cummins 335 chanced to three ring pistons and changed the piston profile for efficiency.

The graph for the 190 with C3 injection looks very strange. Why that huge gap? If the engine can take so much boost on the rest of the altitude range, why not shift to the second speed sooner and get rid of that huge gap? It seems to be using the same shift point as the lower power setting, but surely the engine controller can alter the shift point at different power settings. The blue line and the purple line seem to have two different shift points. Also why does C3 injection have a longer time limit than the purple line if the fuel hasn't even changed?

Greg, I restore antique tractor carburetors and they too mixed SAE and metric. The Zenith K 5 carburetor was used on International Harvester (Farmall) equipment as early as 1931. All external threads are SAE. The internal threads are metric. My favorite: the idle jet has a SAE hex (9/32") and metric threads (M 8 x 1.0). Who knows why? This carburetor was most certainly made in America.

Interesting video. One advantage of WAlies was sodium filled / cooled valves.

How in the world did you manage to gather, digest, and present all this highly technical and in depth amount of knowledge od such a specialized area into your videos? I am a professional mechanical engineer, yet the amount of knowledge is baffling.

Didn't see this coming, thanks Greg. 🐱

Excellent. Thanks again.

Excellent video. This will be getting a second viewing, Was there going to be another video on the P38? I thought there going to be a comparison with the Mosquito?

I can translate from Russian, if you need to. Depends on the volume of the text. My soft copy of "Instruction to a pilot about operation of aeroplane La-5 with motor M-82 (Sic!)" runs 33 pages of plain text with no pictures at all, which is a quite an amount of work. Also, I can record and send pronunciation of Russian words and abbreviations, whenever you want to make a video mentioning Soviet technics.

Reduction of the number of compression rings occurred as a result of improvements to materials, coatings, manufacturing, and design. It used to be that the engine manufacturers had to choose between low oil consumption and low ring wear. If oil control to the cylinder was improved, ring wear would increase due to lack of lubrication. Advent of chromium plating allowed reduction of oil consumption while not causing high wear. Engineers' understanding of ring dynamics and pressure balance due to instrumented testing in running engines allowed improvement to ring design to make each ring more effective. Cylinder bore finishing has improved a lot from optimization of cross-hatch specifications and use of deck plates while honing to make straight, round bores in the assembled engine. This allows use of lower tension rings that reduce friction and cause less bore wear.

Interestingly enough, the Soviets did eventually do something similar to what you proposed it would require to copy the American engine with their metric system. In their copy of the B-29 (Tu-4) they managed to convert it to metric measurements while maintaining a very similar design. Of course this is much easier on the scale of a large aircraft but it is still an interesting application of a conversion from imperial to metric.

kzfaq.info/get/bejne/i7xjhdpztdfenok.html For the bore versus stroke discussion. The engine cross section is a big impact, one of the FW190 replicas in the US used an R-2800 instead of the ASh-82 and you can clearly see the cowl has been modified for a bigger diameter. Whereas the other replicas use ASh-82s in place of the 801 happily.

Cool. Nice to see some info on Soviet engines

The screw threads vary in shape as well as size. Whitworth in particular looks quite different. Almost all Bristol radials have a 5.75” bore, but stroke varies between 6.5” and 7.5” this includes both poppet valve and sleeve valve types. This strikes me as being a little weird.

33:45 81. At altitudes higher that 4000-4500m turn on the second speed of the charger.

Such an unique content ! BTW, a question : why the use of iron cast cylinders instead of aluminium with steel liner ? Was the technology of the time not advanced enough ? This would have saved a substancial weight.

Hey Greg, awesome video, as always. Concerning the C3 injection, the A8 used a different modification, which simply increases the manifold pressure without the charge cooling the C3 injection system provides. Would be interesting to know whether the C3 system had any advantages over the Erhöhte Notleistung system.

Hey Greg! Maybe one day a video about aircraft engines in tanks or other vehicles? Ahhaha

Hi, Greg, great vid as always, have you entertained the idea of doing something on WWII motorbikes? Best regards and keep up the great work.

Hello all. Am I right in thinking that the BMW engines were also, in a way, developments of the Siemens/Bramo engines, which evolved in part from licence production of American radial engines? It might be worth consideration for a future episode, Greg: the family trees of the major engines of the late 1920s/early 30s and I think they were influential in other countries, too.

Another fantastic video! Another thing about the La-5 and 190 is that they don't scale down very well. I've been flying RC scale fighters since 1971, including years as a designated test pilot, and they are two of the worst WW2 single engine planes; with one caveat. The 190 is easy to fix, just increase the horizontal tail area a bit for pitch stability and she's a sweetheart but doesn't look quite right to the trained eye. I have no problem with sacrificing a little scale fidelity to make a plane fly a lot better. To the best of my knowledge, no one has built a Lagg or Yak-1-9 or Mig 1 or 3 that made a good flying model. Highly tapered wings, relatively short tail moment, lots of "beef" in the rear fuselage, and rather marginal verticle fin area combine to make a model that's nearly unflyable. The best scale fighter models I've flown? The P-39, of which I've had four, is, IME, the best by quite a margin. The long nose and large tail feathers provide an excellent mix of stability and maneuverability. It gets tougher to choose after that. The P-47 is probably next and it only suffers compared to the Cobra because of much higher drag and, usually, greater weight because of the huge fuselage. I had the chance to fly a P-47 with nearly identical stats to one of my Cobras and the only real difference was needing a little more throttle in landing configuration. I've flown one Typhoon and it's right up there too. I suspect the F4f and F6f would make excellent models but, other than a small foam F4f, I haven't flown either. The little Wildcat flew like a dream. Most of the rest fall into the "quirky" category. Not treacherous but you really have to know your plane or it will bite, usually through lack of skill with rudder and throttle. The 190 would be here with the enlargement of the horizontal tail surfaces or a little higher. Then we get the ones non-experts should stay clear of. All the Soviet fighters, Corsair, P-40, and the Spitfire. I mentioned the Soviet fighters and the P-40 has similar issues although the big chin radiator is more an issue than lack of tail surface area. The inverted gull wing of the Corsair can cause all sorts of unexpected gyrations but the one that might surprise people is the Spit. R.J. Mitchell designed one of the best fighter wings ever but it doesn't scale down well at all. I've flown a couple good ones with carefully designed airfoils but some companies don't bother and some don't even include the "washout", wing twist, that made the full scale outstanding at the edge of a stall. Most model Spitfires will tip stall with no warning and using ailerons instead of rudder at low speeds is a guaranteed disaster. I haven't flown as many twins but I can tell you guys the best and worst I have flown. The Bf 110 is, hands down, the best. The P-38 is very good until you get close to stall speed. Stay away from the Mosquito! I've only flown one, and it was HARD, but I've watched some dang good pilots turn them into a pile of pieces with one little mistake. Scale models don't tell you everything about a full sized plane, otherwise we wouldn't build full size prototypes, but they exacerbate things that might have been very minor with the real thing. They have, if nothing else, taught me enough to think I would choose a 110 over a Mosquito to perform night landings in a crosswind and I would not, under any circumstances, hold a Soviet fighter in a spin for more than a turn or two or attempt a "three point" landing in any of them. Cheers!

I love Radial engines!