Would be nice to know mention what are the problems of inverted V engine layout I suggest as a topic for next video diesel engines 5TD and 6TD of T-64 and T-80UD tanks, may be also V-2 diesel of T-34
Until you consider how much wear and tear they would suffer from spinning as such high rpms imagine replacing each individual gear compared to simply getting a new belt
@@randomrayquaza2044 This engine spins at 3000rpm. The engine of the Honda CBR250RR mc22 hit almost 20'000 rpm and used guess what? geared camshafts. Turns out it's one of the most reliable engines.
@@randomrayquaza2044 i design and make industrial machines. I've seen things made in the 50s working 24/24 with gears still brand new, at speeds higher then a combustion engine. The machine is immortal
Why did the Germans make inverted inline engines?: Because they were required to do so by the visionary head of engine design at the RLM (German Air Ministry) Dr Helmuth Sachse in the early 1930s. He required all new engine designs to have fuel injection single stage superchargers, and inline engines were to be inverted and to be able to accommodate a cannon firing through the propeller hub. It was no coincidence that the Daimler-Benz 601, 603, 605 and Junkers Jumo 211 and 213 engines and Argus were all structured this way. Strangely enough Sachse was good mates with his opposite number in England, Major George Bulman, . At their last meeting (in a Munich beer hall in 1938) Sachse complained to Bulman about how difficult it was working under politically driven Nazis who failed to understand what he was doing. He was convinced his unimpressed attitude toward them was going to get him fired and he was right. He was quickly snatched up by BMW who made him the head of piston engine development, where he oversaw the development of the legendary BMW-801 14 cylinder radial which powered many Luftwaffe aircraft, including the venerable Focke-Wulf FW-190A series. This engine may have been the first to include a mechanical computer, the 'Kommandogerat' which automatically managed propeller pitch, mixture (and spark advance?) which freed a hard-pressed fighter pilot from having to deal with engine settings while trying to score victories and stay alive. Power, weight and Fuel: During the Battle of Britain... The DB-601A displaced 33.9L (2,069 cu in), developed 1,007 kW (1350hp) and weighed 660 kg (1,455 lb) with 6.9:1 compression ratio, for a power to weight ratio of 0.928 hp/lb, using B4 fuel of roughly 87 octane equivalent fuel. The Rolls Royce Merlin III displaced 27.04L (2,069 cu iin), developed 775 kW (1030hp) and weighed 624 kg (1,375 lb) with 6.1:1 compression ratio, for a power to weight ratio of 0.749 hp/lb, using 87 octane fuel. It didn't take long for the RAF to upgrade to 100 octane rated fuel, improving the Merlin's output to 860 kW (1150 hp), but the development of high octane equivalent fuel in Germany was accomplished by a complex combination of additives derived from coal hydrogenation with lower octane equivalent B4 type fuel, which arrived after the Battle of Britain. So although the DB-601A displaced more than 25% than the Merlin III, it weighed only 6% more and when both used ~87 octane fuel it delivered a 31% higher maximum power. At the National Air ans Space Museum Smithsonian campus there is a Merlin on display behind a description claiming (as I recall) it delivered the highest hp output per cu in displacement of any WW2 V12 inline engine. However we can see above that there is more than one specification one needs to know when comparing engines. Coolant temperature: The Rolls Royce Merlin did operate at a higher coolant temperature than the DB-601. The higher 120C coolant temperature of the Merlin compared with the 90C equivalent of the DB-601 meant that the frontal area of the Merlin's radiators could be less, causing less parasite drag and permitting higher aircraft speed. To make this work, Rolls Royce had to develop lightweight plumbing and radiators that could withstand both the high pressure and temperature of the coolant.Willi Messerschmitt complained about this to Daimler-Benz but to no avail. Part of the reason may have been Germany's lack of strategic metals like nickel, chromium, copper, vanadium and others that were needed to make ideal high temperature alloys. Their metallurgists knew how, but the materials were not available in quantity while Allied engine builders could draw and ore from the natural resources of the entire British Empire and the United States. This also compromised Germany's gas turbines, which suffered serious engine life, reliability and logistical support issues. To me it speaks volumes about the quality of that Germany's overworked engineers that they were able to produce such competitive engines in spite of this. Direct Fuel Injection: Oddly the otherwise astute British examined the concept of direct fuel injection in the 1930s but discarded it as offering no advantage over carburetor induction. Germany's engine designers would cause them to regret that decision. The Bosch direct injection systems in the Daimler-Benz engines offered a number of advantages, some of which were not obvious... Unlike carburetors which regulated fuel flow with float chambers, direct fuel injection systems were not affected by G-forces. A Bf-109 pilot with a Spitfire on his tail could shove the sick forward and try diving full throttle to safety knowing his DB-601 will give full power. A Spitfire pilot with a Bf-109 on his tail could not do that - the negative G forces would close the float valve in his Merlin's carburetor perhaps stalling the engine at a very bad time. He had to roll upside down first. The Bf-109 was designed from the outset as a short range interceptor to be used as part of Blitzkreig warfare. It then found itself having to escort bombers across the Channel during the BoB, for which it lacked range. Limited to 87-90 octane equivalent fuel, it had a larger displacement than the Merlin and although it offered a comparable or better power to weight ratio, it had to burn fuel at a faster rate than did the Merlin to output comparable power. Direct fuel injection ensured the maximum possible efficiency of fuel usage. For each cylinder, the precise amount of fuel required was injected at exactly the right instant for the right duration, limiting waste. The range of the Bf-109 would have been even shorter had it not been for direct fuel injection. Direct injection meant that the inlet manifolds carried only air, not an air-fuel mix. The closing of the inlet and exhaust valves overlapped, leaving a brief period where both were open at the end of the exhaust stroke. This meant that air from the inlet manifold briefly passed through the cylinder and out the exhaust, helping to cool the block, head and exhaust valves reducing the chance of knocking due to a hot engine. Because of the aforementioned shortage of strategic metals, preventing excessive engine temperature was always an issue with the Daimler-Benz engines. Excellent video Francis - fabulous graphics that make normally obscure details much easier to understand. It would be a great companion to Douglas' book. I was investigating whether I should try modeling and animating a DB-601 myself, but you've done it! I wonder if it's possible to export solid geo files from Solidworks to Houdini? Thanks again! (Continued in the Reply....)
(Continued from above...) Supercharger: What we call combustion is the oxidation of a hydrocarbon like octane to carbon dioxide plus water (or as close as possible). 25 Oxygen molecules are required to oxidize every 2 octane molecules. Engine power is just as dependent on oxygen as it is on fuel. As an aircraft climbs, the the density of air (which is ~21% oxygen) falls off, which means the oxygen falls off and an engine which developed 1500 hp on the ground might only develop 1000 hp or less at 20,000 ft. As explained in the video, the object of an aircraft engine supercharger is to minimize the loss of sea level engine power at higher altitude. Compressing the air gets more oxygen molecules into the cylinder, so more fuel can be burned and more power delivered to the propeller. Superchargers are rated to work best at a specific altitude, above which their effect declines and power falls off again. Adding extra air pressure and thus combustion charge at sea level where there was already plenty of oxygen would likely destroy the engine. Before the DB-601 the supercharger had to be disabled until the aircraft climbed to somewhere near rated altitude, during which the pilot had to live with declining engine power. Once they were close enough to rated altitude they could safely engage the supercharger and enjoy full engine power again or something like it. Dr-Ing Karl Kollmann's supercharger for the DB-601 changed that. As I understand it, the supercharger could be left on for the whole flight. The engine charge was based on altitude constantly being adjusted by an aneroid barometer which drove a fluid coupling similar to a car automatic transmission torque converter between the supercharger impeller and the engine to deliver the ideal charge for a given altitude. At ground level the supercharger ran but delivered very little charge (which is why DB-601 and 605 engines have a distinct whine or whistle near the ground). As the aircraft climbed, the charge was automatically increased to ensure the engine could always deliver maximum power output all the way to supercharger rated altitude. Beyond that, power started to fall off again, like a conventional supercharger. IMHO, this was an inspired piece of work. The DB-610 Yes 2 x DB-605 coupled via a common gearbox was called a DB-610, but before that 2 x DB-601 coupled likewise was the DB-606. The DB-606 was a complete disaster - responsible for the deaths of many Luftwaffe bomber crews. It was a nifty way of stuffing 2 engines into a small space mostly within the wing that caused lass parasite drag than 2 separate engine nacelles but it came with major problems, the biggest of which was its tendency to catch fire. The DB-606 had worked well in the high speed prewar Heinkel He-119 experimental prototype bomber/reconnaissance aircraft but it turned out to be disastrous for the Heinkel-177A heavy bomber causing catastrophic fires to such an extent that their crews refused to fly them. The DB-610 was definitely an improvement but coupled engines were always a stopgap measure. This very nearly ruined Heinkel and amongst other things caused them to cancel their He-280 jet fighter because they simply didn't have the engineering staff put out the fires in the He-177A program while further developing what was the first jet fighter to fly. As an aside, it's interesting to compare the He-177A with the Avro Manchester which also came with unreliable high powered Rolls Royce Vulture engines. The British Air Ministry cancelled the Manchester but allowed Avro to design a new version powered by 4 separate Rolls Royce Merlins and the result was the Lancaster. Heinkel (according to his autobiography) was forced to make the He-177A work with coupled engines even when he offered a more conventional version. The same air-frame fitted with 4 x DB-603 engines (secretly in Heinkels Vienna-Schwekat plant where the RLM couldn't see it) and the He-274 built by Farman in occupied France with the same air-frame and 4 separate engines proved how sound the He-177 air-frame design had been all along. Thanks to the DB-606 and DB-610 and the RLM, Germany was denied a potentially first class heavy bomber as well as a jet fighter alternative. The real problem was Germany's inability to develop a reliable high power engine like the big American Wright and Pratt and Whitney radials or the British Napier Sabre. They just didn't have enough engineers to both oversee production of current engines to meet wartime demands plus develop new ones. Government oversight of engine development by the RLM was nowhere near as good as it was in Britain and a great deal of time and resources were expended for no useful contribution to the war. The promising Daimler-Benz DB-604 24 cylinder X configuration engine was cancelled while rival Jumo-222 4 x 6 24 cylinder engine ran into conflicting RLM demands along with technical challenges with too few engineers available to deal with them. When it finally started entering service in late 1944 it was unreliable and clearly not yet ready. ---- Anyone interested in WW2 German or British propeller engines really must read The Secret Horsepower Race by Calum Douglas. It's a brilliant book written by an F1 racing engine designer who also speaks German, who spent 5 years researching and writing the book based on archived wartime official documents. He also managed to acquire the original notes and documentation of the late Dr-Ing Karl Kohllmann - who with Dipl-Ing Fritz Nallinger was one of the chief designers of the DB-600, 601, 605, 603 engine family. He also separately translated a paper Kohlmann wrote about the theory and practice of engine supercharging. The Secret Horsepower Race is a super-detailed, well written and illustrated book that includes so many fascinating stories about how and why these engines became what they were. www.calum-douglas.com/ Excellent video Francis - fabulous graphics that make normally obscure details much easier to understand. It would be a great companion to Douglas' book. I was investigating whether I should try modeling and animating a DB-601 myself, but you've done it! I wonder if it's possible to export solid geo files from Solidworks to Houdini? Thanks again!
@@tsegulin DOHC 4 valve engines takes up a lot of space and are heavy. A big block Chevy push rod fit straight in to Porsche 928 replacing a 5l. A 6l small block Chevy can replace a 5.3l jeg V12 in a XJS and the Chevy weight much less. I wonder how much displacement one could get in a "Chevy V12" aircraft engine within the space comfines of a RR Merlin. 45 liters? 2 large valve is not that big of a handicap in a supercharged low reving engine.
You have an error, you list the cubic inch for both rolls royce merlin and db-601 as the same but you have their liter displacements as different. If the cubic inch displacement is the same for both then so would their liter displacement. So something is wrong here. @tsegulin
@@JuniorJunison You are correct, the cu in displacements of the two engines are not the same. DB 601 should read 2069 cu in Rolls Royce Merlin should read 1,650 cu in. The metric displacements are correct. Sorry, my bad.
@@datvik7187 This certainly has to do with the complexity of the design and therefore the high cost of production. For this reason, NASCAR race cars still run with carburetors by regulation. This is also just to keep costs down.
@@christophermikrowelle7093 It's my opinion that Mercedes could have absorbed the costs in their R&D. After all, they charge a premium for their cars, not to mention they LOVE making complex systems in their cars.
Actually, the original steam engines had the cylinders at the bottom and crank or beam above so this V12 is "right-side-up". When engineers decided to put the cylinders on top and crank at the bottom, they were called "inverted" engines, which became the norm.
@@kingcosworth2643 No, just drip-lubrication with oil-cups and greasers climbing all over them with oil-cans. I think you'd have to have quite tiny midgets lubricating this V12 ;P
I remember a video where a guy sent a DB601 crankshaft into RR to have it measured and checked. The engineer at RR said the specs were spot on to its very high tolerances He said don't drop it because they couldn't make another like it the tolerances were so exact with their modern equipment. Imagine they were doing this in the thousands under constant bombing of their factories.😮
The machining of the P&W 2800 was so precise that there was no gaskets between the engine block halves. The Germans were astounded by the quality of those engines. Some of the generals knew they were going to lose because of Americas industrial strength.
@johnarnold893 This isn’t particularly impressive. Most aircraft engines don’t use gaskets between the crankcase halves because unlike automotive engines the main bearings are incorporated into the crankcase and don’t have separate caps. If they used a gasket the preload would change as it compressed or expanded leading to a spun bearing or catastrophic failure of the through studs that hold the combustion forces. They typically use a silk string to act as a gasket.
This story is repeated of just about every WW2 era engine being examined by another manufacturer, it's so old it has hairs on it whether it's Pratt & Whitney, RR, DB601, Merlin or whatever. Those engines were made with fixed jigs and tooling rather than CAD/CAM/CNC. Making the jigs and tools, providing the sharpening and adjustment data etc. only makes sense if you are tooling for large numbers. Bombing factories in WW2 was so imprecise that it was rare for tools and machines to be hit, and in any case there would typically be multiples on the production line. The cost of doing the metrology on a DB601 crank, then feeding it through to the program and tooling, would also be uneconomic for a single crank. Making it from billet would involve a great deal of machining, forging it would add to the tooling cost. You would also probably need to have details of the alloy in use and its heat treatment, which would involve testing the sample crank in different places for hardness, ductility and modulus. The 1940s engineering was as good as it could be but today we could easily design and make better engines - the reason we don't is that whole economy of scale thing, no new piston aero engines because the production volume wouldn't justify the sunk costs before production started.
@@johnarnold893 The industrial strength was quantity not performance. Individual German tanks, guns and aircraft were often better than Allied ones but could only be made in small quantities (indeed the main benefit of bombing Germany seems to have been the diversion of so much effort into producing the 88mm Flakcanone in volume.) The German joke was that one Tiger could defeat ten Shermans but the Americans always seemed to have eleven Shermans.
Waking up to this was an unexpected surprise. I never heard of a hydraulic supercharger and it's counterintuitive to me that higher compression ratios are better for fuel economy. Very interesting and informative. This is my first comprehensive look at the Messerschmitt BF 109 engine after learning about it decades ago.
at rarer air bars its often not even a choice - less fuel is needed for the same net thrust provided you find a way to have the chamber bars higher, hence supercharger
Higher compression engines paired with higher octane fuels and part-throttle operation makes for improved fuel economy when maintaining a constant cruising speed. It's about sipping the good stuff for power.
Technical yet very clear. Thanks, I've always wondered why the German V-12 was inverted when no Allied engine maker tried this. Lots of stuff in there I didn't even know I didn't know!
Ok, let me see if i get this right...... It's a 33 liter 12 cylinder 2000 horse power engine with variable speed super charger, dry sump , high pressure direct cylinder fuel injection, inverted, multi- displacement, gear driven cam, nitrous oxide or methanol injected rated, 4 valve dual over head roller rocker valve train,dual ignition system, roller bearing connecting forged rods, that only weighs 1300 pounds and yeah you can shoot a cannon thru it while its running and it was designed in the 1930s ??????!!!!! I feel like engine designers nowadays need to stop bragging.
I can imagine these engines consumed huge amounts of oil. I had a BMW motorcycle where the engine was flat on it's side and when you parked it on the kickstand the "top" side was angled slightly downward. Every single time you parked the engine there was oil seeping past the rings into the combustion chamber and there was ALWAYS white smoke on startup - LOTS of white smoke on cold starts in the morning.
Oil leakage causing detonation, and fuel diluting the oil, were problems with the DB series. The original Zündapp boxer motorcycle had a cylinder angle of, I think, 170 degrees or even less, so that the oil would drain back, at least in sidecar form. In my view BMW should have gone for a wide angle V. The difference in vibration wouldn't have been much, though it would be on the rather silly huge boxer they are now making.
11:36 Fiat?! That's a Rába Bf-109G-2 Built by Rába in Győr, Hungary under license. That is NOT an Italian Bf-109. Fiat and Alfa-Romeo built the engines under license to domestic Italian Fighters, like the Macchi C.201, Reggiane Re.2001. Kawasaki and Aichi both recieved the license, because Japan had a severe interservice rivalry, and the Navy and Army would not want to share an engine, or aircraft. Aichi produced for the Navy, and Kawasaki produced it for the Army. The other thing you missed is that Germany didn't have a fuel shortage when the engine was developed, the Injection was specifically developed for manuvering advantage, and the MW-50 injection was used for energy traps as well, since with the extra power, they could actually have both the horsepower, and airframe advantage over the P-51D. The inverted design was sought after specifically for leaving more space over the engine, enabling the installation of machine guns, and giving better visibility for the pilot.
@@dougerrohmerIt wasn't an inability to make high octane fuel, it was the inability to make enough high octane fuel--actually, enough of any fuel--to meet it's constantly increasing needs. High octane fuels were available prewar, viz. speed record attempts. DB 601N engines used C3 high octane fuel in 1940, and, by late '41 all FW-190's used C3 for their BMW 801D's until the end of the war.
The power and rpm figures are manifestly wrong. The engine produced 1000 PS at 2300 RPM and 1.3 Ata and 1100 PS at 2400 RPM and 1.4 Ata (according to the engine tech-manual for the DB-601 A). The N-Model (DB 601 N) allowed up to 2800 RPM at 1.4 ATA and produced 1280 PS. The inverted configuration and the way the piston sprayed the oil in the crankcase produced problems with foaming at high RPM, thus the later DB engines were all fitted with defoaming devices to allow higher RPM in the DB601, 605 and 603. Also the DB601 didn't have a pressurized cooling system (the DB605 had).
Great video An extra advantage of the inverted engine was that the distance from the crankshaft to the upper surface (piston case or what would have been the sump) is reduced. Since the distance from the that to the upper fuselage is driven by allowing the pilot to see forwards, the plane could have reduced frontal area. I didn't describe that well- hope you can understand it.
The Merlin and Allison engines used a water/ethylene glycol mix to allow higher temperature coolants, and thus smaller radiators, without requiring a highly pressurised system. It ran at about 120C. I wonder why the Germans didn't try that approach. Maybe they just didn't have the capacity (the British got their ethylene glycol from the USA). Incidentally, there were bf109s with V12 engines the "right way up" in the form of the Spanish licence-built Hispano Aviación HA-1112. However, the Germans could not provide the DB605A engines as they needed all they could build once WW II started. Consequently, the Spanish installed the Hispano-Suiza 12Z V12, which was similar capacity (36.5 litres) and had the same provision for a hollow propeller shaft to accommodate a cannon barrel. After WW II, when surplus Merlin engines became available, then those were retro-fitted to the Hispano Aviación HA-1112 fighters. They can be seen in the film Battle of Britain, as the producers leased a number of those Hispano Aviación HA-1112 fighters and painted them up as Battle of Britain era bf109s. However, you can clearly see the give-away that they were Merlin engined from the higher line of the exhaust stubs. They would also, of course, not have sounded like a DB605A engine either, but the producers just dubbed the "correct" sound in. So to what extent the adoption of a conventionally orientated V12 affected the performance and flight dynamics of the bf109, I really don't know. But clearly the inverted engine format wasn't absolutely essential.
@@EbenBransome The Merlin I, II, and III series all used pure ethylene glycol coolants. That presented problems, not least with it being highly inflammable. From the Merlin X on, a water/ethylene glycol mixture at a ration of 70:30 was used, and that seems to have remained. First it is a fact that RR used a water/ethylene glycol mix an settled on a ration of 70:30 as the best compromise (which they used from the Merlin X onwards). Also, the lower heat capacity of ethylene-glycol does not, in itself, cause radiators (or rather heat exchangers) to be larger. Quite the opposite as they can run hotter and exchange more heat through a given surface area. Where the reduced heat capacity of ethlylene glycol does come into play is in how fast the flow rate has to be. One half the heat capacity, then twice times the flow rate and there are also some conduction issues. The prescribed coolant temperature at high power output levels, such as when climbing fast and in combat was 120C, although some later models were allowed very short periods at 135C. In practice, the cooling system of the Merlin and its prototypes evolved quite a lot. Originally it was intended to use evaporative cooling, but it proved unreliable and hence the move to ethylene glycol cooling in the earlier engines. Later it move to the water/ethylene glycol mix.
@@TheEulerID Your explanation is correct. I deleted rather than editing my original post for better clarity. I do take some issue with your other statements. Because of the greater viscosity of glycol, attention has to be paid to the flow paths especially in the cylinder head. But also high glycol mixtures have more wall adhesion in heat exchangers than straight water, so more circulating power is needed.
@TheEulerID Thanks so much for your reply, it was informative and fascinating. I knew of diesel being more power dense because of it being less refined. My reasoning was that, the first thing manufacturers did during the first U.S oil crisis in 1973-74 to improve fuel economy was to lower compression. I learned so much from your reply.
Did anyone else notice that the propeller blades were pitched backwards. In the animation of them rotating, they would be pushing the air in the wrong direction.
You should look into the Napier Saber engines. They are a wonderful and slightly weird engine that uses sleeves instead of valves to exhaust and intake air.
Napier were pretty crap at sleeve valves. It was Bristol who perfected them and made them in volume, they had to help Napier with the sleeve design and manufacturing. The Bristol Centaurus produced about as much power as the double Daimler engine, from 18 cylinders. But by the time they were fully developed they were heading for obsolescence.
@Kenneth-p1b The early Sabres had a host of faults including unforgivably poor quality control. It took Bristol to fix the sleeves and the EE takeover to get some shop floor discipline. I believe the common American belief that they productionised the Merlin and early examples they saw were handmade was confusion with a couple of Sabre samples sent to the US which had indeed been hand finished. RR was set up to produce Merlin engines in volume from the start.
10:38 Interesting fact: To beat early marks of Spitfire that were chasing them, Luftwaffe pilots would put their Bf 109 into a steep dive. As the negative g force would starve the Spitfires carburettor of fuel. The fuel injection of the Bf 109 wasn’t affected by g forces.
Answer is easy and no mystery: a V engine upside down puts the small end of the engine up, allowing for a narrower canopy, hereby increasing visibility for pilots by a big margin. Recall the "hun out of the sun"? German pilots were able to spot their enemies much earlier
Hun in the sun was an expression used in the First World War. At dawn the Hun attacked from the East with the rising Sun behind them making it difficult for the British and French forces to see the enemy due to being dazzled. Nothing to do with the shape of the engine.
Everything is very clearly and neatly laid out, I just noticed that either the propeller is rotating in the wrong direction in the entire video material, or the angle of the blades in the direction of the aircraft's movement is incorrect
Tower Shafts and bevel gears were standard for inline aircraft engines. Gears also drove the magnetos, oil pumps, foolant pumps and mechanical superchargers. Botton end bearings could be plain or roller type. Radials it was common to use ball bearings on the crank. The cam rings were driven by external and internal spur gears. The cam ring in an 18 cylinder radial often turned wt 25% of crank speed. Props in all engines except low powered direct drive engines used speed reduction drives to keep prop tip blade speeds below the speed of sound.
@1:57 "if the engine was stopped for a long time, the cylinders could become flooded with oil and the spark plugs had to be removed and cleaned." No, that isn't the main reason, and that is why this video was definitively not written by any airplane mechanic. If oil gets into the cylinder and the engine is rotated by a starter without draining the oil first, the rods will bend (fluids don't compress) and the motor will have to be rebuilt. This is called hydraulicing by most mechanics. That is probably the main reason that the Allies didn't want to use an inverted V-12, because it was so easy to hydraulic the motor. It may have required that the spark plugs be cleaned, but the main reason was the hydraulicing that would damage the motor. This is why you don't just start an engine that has ingested water - it will destroy the engine. You have to pull all the spark plugs and spin the motor over to force all the water out of the cylinders. If you've ever wondered why you have to pull the prop through two revolutions on a radial - this is why. You have to get the oil out of the bottom cylinders before spinning the engine over.
He was referring to removing the spark plugs to drain the oil and also cleaning the spark plugs as a secondary thing, obviously the main thing is to drain the oil through the spark plug holes.
Because of the fuel injection it was possible to keep both intake and exhaust valves open for a certain time. This increased the gas exchange in the cylinders.
In these inverted engines, how did oil from the crankshaft or the under sides of the pistons get back into the oil system, and not try to drain past the rings towards the combustion chamber?
Very well done !! An upside down engine for airplanes they used was brilliant, and I wonder why more countries did not use it. The mechanical injection had issues, but it worked! It was stupid the way England slaved themselves to carb's even with the choke point regulator hack. A few minor points to mention: Germany never seem to master the high pressure coolant problem, compared to the British and Americans. They always had issues with it, and many engines only lasted 14-20 hours. Germany's main fuel and lubricant sources was coal converted to low grade fuel. They never got over 80-90 octane, where England and America eventually got up to 130 octane. The NITROUS OXIDE was Germany's secredt weapon! And it took YEARS for England and America to figure it out. Although water injection to cool the cylinders was an old racing hack. The Turbo's - and Nitrous - LOVED low compression ratio's and that worked out very well. The dual engine concept never really worked out. Dual sparkplugs another brilliant idea, you are right, they needed to be opposite or further apart. Kawasaki cruiser motorcycle still use this concept today!
Actually, much in U.S. & England compared very favorably. What this video did NOT tell you was the rapid, steadily decreasing decline as of 1940 forward of German alloy quality due to inability to acquire sufficient strategic metals for their production requirements: manganese, chromium, nickel, moybdenum, copper, aluminum, vanadium, cobalt, tungsten--even high quality Iron ores. More exotic metals like platinum, beryliium, indium were out of the question. That's why there were unending problems with their engines, such as valves that burned & corroded causing detonation, spark plugs that would not last, and non-competitive lead-babbit bearings that could not endure high boost pressures and corrosive fuels. You ever notice grainy quality of German WWII film? Yeah, even silver was in short supply. And not enough chromium to produce stainless steel. They were working at an alarming strategic material disadvantage, and, unlike US or USSR, could not compensate with higher production capacity than their adversaries.
@@josephstabile9154 Also the Germans had a shortage of skilled workers, then a shortage of semi- skilled workers and eventually even resorted to slave workers who took every opportunity to sabotage whatever they were forced to make for their oppressors.
@@Willheheckaslike If I correctly follow you, you're asking about the 60 Series RR Merlin, that is to say, the 2-stage supercharged Series, as used in the Mk IX (and others) Spitfires. This engine allowed higher boost pressures, ultimately (late '44/'45) in the range tof 72" hg with 150 octane avgas, famously in the Packard Merlin equipped P-51D. As the British were striving to keep the Merlin competitive, especially during the crucial time of the introduction of more advanced models of the Bf-109, and of the FW-190, the USA was of great help with its advanced silver/aluminum/indium bearing technology, and its iridium electrode spark plugs. These technologies were what allowed the Merlin to be able to endure the much boosts pressures that 2-stage compressors, intercoolers & high octane promised. Implied in that, the necessary strategic materials/exotic alloys were available to the USA, and therefore to Britain. Germany, after '40, had to increasingly restrict its industry's use of these materials, some of which it never had access. By mid '44, the lack of alloying materials was so severe that German armor was developing unacceptable levels of cracking upon impacts, and transmissions/gears were also failing at higher levels. Some of this can be attributed to falling/rushed production standards, but mostly to lack of strategic materials. To quote Albert Speer, by end of April '45, the total amount of strategic ores remaining in Germany could be enclosed in a broom closet.
You are right, they did not compare. The same displacement RR Griffon had superior metallurgy, superior supercharging, massively longer engine life and 50% more power. It’s hard to be a Wëhräböö in grown up discussions.
I’m already amazed by the timing systems to be able to fire through the propeller arc. Whoever decided to yeet a 30 mm through the engine was definitely thinking outside the box.
Adding 2 engines for the DB610 reminds me of the video talking about the differential. In order to increase the engine output, we will put in ... MORE engines.
Well done! Most sources just say, "Well, uh, moves the engine out of the pilot's line of sight and allows through-the-prop and top gun placement. You dove MUCH deeper!
The video was called Inverted V12 WHY?!?. It's a pretty good video, but most of the info was not about WHY!?!? Inverted V12, it was technical information about HOW?!?! this V12. So yeah he dove deeper into HOW!?!? but not into WHY!?!?, which really boils down to aircraft geometry. It's not like you can't have a supercharger or fuel injection on other engines.
I can just about change the oil on an engine i am not a motor head, however the engineering and technology involved in this 1940's engine is facinating, infact incredible
You left out a tiny detail on the DB 610 - it had a real nasty habit of catching on fire. the sole reason the HE-177 was apiece of flaming crap. Great animations!
I really enjoied the video. I live learning about this stuf but you may want to change the direction the prop turns or the pitch of the blades. Currently the prop is blowing the air backwards. Thanks for the video!
You have to consider the differential in temperature between ambient and the radiator. All things the same a hotter radiator will dissipate more heat than a radiator at a lower temperature, that's just basic heat exchanger stuff. That would let the radiator be smaller as well as the fact that it doesn't even need to cool the coolant as much since it is supposed to run hotter. Makes perfect sense, besides running an engine above 212 degrees being really, really infeasible...
No, that is completely wrong. If the radiator is running at a higher temperature, then the temperature gradient is higher which means the rate of heat transfer per unit area is higher. Thus if the radiator (really better called a heat exchanger) runs at a higher temperature it can be smaller and requires less air per unit energy transferred.
Excellent graphics! Another video comparing the Merlin with the DB601 would be good. At the beginning of the war the 2 opposing engines had near identical output and the respective aircraft Bf 109E and Spitfire Mk 1 had near identical performance. As the war progressed the DB 601 started to fall behind as did later models of the Bf109.
I didn't really get that crucial advantage of up side down cylinders. But troubles with spark plugs and hydro locking - obvious down side. It seems like no one else used that layout at the time
I just wanted to tell you that I subscribed to your channel and I like your channel because I like it very much because it is shown it with a video and all I like features in the morning and the evening and in the morning to then I was watching videos so it's a nice show and always see individual played at the TH-cam channel here I can subscribe where it is awesome to see how it is done from the engine to see it when it's rotating and the opposite side with the cylinders with two spark plugs I didn't know that and that's awesome to see when there is a spark plug on the other side but the next to each other then again I would like to say this is an awesome video
Alison (US Aircraft) Coupled two of their V-1710's together also. This is the very rare V-3420 (although technically it was a "W" engine just like the DB. It was never quite perfected, and with the advent of British Jet Engines, Alison stopped the program entirely,. However, the "V-3420" drove a fancy gearbox that turned Counterrotating Propellers, which was a fad for awhile. In my opinion only the British got this right... In all but a very few cases, instead of a Huge Engine driving a complex gearbox (which was the source of most of the failure that almost always resulted in a crash*), they went with (most of the time) with two standard engines per Counter-rotating propeller set! Each driving it's own propeller to achieve the same counter rotating affect! *like the Hughes XF-11 crash after a gearbox failure cause the right hand propeller set change the pitch with one propeller going into full reverse thrust and the other went to fine pitch (which produce very little forward thrust. Just before Howard Hughes got to a golf course, the forward propeller went to zero thrust and this, along with other factors caused the crash that nearly killed H.H.!
The lower C of G is a myth, if the cannon tube is on the planes centre line, then the heavy crank and rods are now above the planes centre line.(In cars there are no inverted V engines to keep the C of G low) The higher C of G of this engine helps the plane to initiate a roll from straight and level.
Plain bearings are 100% dependent on oil. Roller bearings too, but as they have "wheels", they can last longer without oil. In both cases, the bearings will be siezed, but the roller bearing will last longer. In fact, plain bearings produce less friction than roller bearings as long as they have enough oil pressure.
It’s to mount weapons in the nose of an aircraft. The oil pan up top allows for more room for guns closer to the line of sight of the pilot and the sights themselves.
It's a dry sump design. That is as much of the oil as possible is scavenged out of the crankcase and stored in a separate tank. That's not unusual - all the high performance V engines in WW II were dry-sumped or else there was a very strong chance of oil starvation under aerobatic manoeuvres. That's not to say it isn't still possible. In the case of radial engines it was normal to turn the engines by hand first to ensure that the bottom cylinders weren't hydro-locked. I suspect the Germans may have done that with their inverted engine designs too.
The inverted aircraft engine wasn't an idea of Daimler-Benz, it was a requirement of the Air Ministry for Air Force Engines. For this reason, the majority of German V-Engines for aircraft during WWII were inverted, Argus AS 10/410/411, Junkers Jumo 210/211/213, DB 603/605. It appears that one of the main reasons for this requirement was easier maintenance. Because, the mechanics could perform most of the work from below the engines.
I have to admit, I do like the looks of the German Stuka but the P51 mustang is my ultimate favorite fighter of old. Today it’s the A10 followed by a close second is the F22 then F15.
It was an issue on all early DB 605's. When they developed the 601 into the 605 they switched from roller bearings to plain journal bearings on the crankshaft, but forgot to increase the oil supply. Doh! Eventually the increased the capacity of the oil pumps, introduced crankshaft nose oil supply, and a centrifuge to de-aerate the oil to reduce foaming. But all these fixes took quite some time.
this is flat out amazing. great work on the video. can you do one about rotary engines such as which was used in the nieuport 17? always wanted to know how they work. especially the fuel systems.
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Would be nice to know mention what are the problems of inverted V engine layout
I suggest as a topic for next video diesel engines 5TD and 6TD of T-64 and T-80UD tanks, may be also V-2 diesel of T-34
Aerospace engineer here - WELL DONE.
This is the kind of video that makes TH-cam worthwhile.
No wonder they lost ww1 and ww2 - too complex for slave labour -easy to sabotage
Exactly right 💯
I agree, some great engineering.
Aerospace engineer here - 100% agree
Civil engineer here but still confirm.
Gear driven camshafts. The ultimate in reliability and peformance. No timing belts/chains to break.
Until you consider how much wear and tear they would suffer from spinning as such high rpms imagine replacing each individual gear compared to simply getting a new belt
dohcs in cars usually are...
@@randomrayquaza2044 Well ... thats the beauty of a 2500~3000rpm engine ... Camshaft is turning at half that so revs are not an issue.
@@randomrayquaza2044 This engine spins at 3000rpm. The engine of the Honda CBR250RR mc22 hit almost 20'000 rpm and used guess what? geared camshafts. Turns out it's one of the most reliable engines.
@@randomrayquaza2044 i design and make industrial machines. I've seen things made in the 50s working 24/24 with gears still brand new, at speeds higher then a combustion engine. The machine is immortal
Why did the Germans make inverted inline engines?:
Because they were required to do so by the visionary head of engine design at the RLM (German Air Ministry) Dr Helmuth Sachse in the early 1930s. He required all new engine designs to have fuel injection single stage superchargers, and inline engines were to be inverted and to be able to accommodate a cannon firing through the propeller hub. It was no coincidence that the Daimler-Benz 601, 603, 605 and Junkers Jumo 211 and 213 engines and Argus were all structured this way.
Strangely enough Sachse was good mates with his opposite number in England, Major George Bulman, .
At their last meeting (in a Munich beer hall in 1938) Sachse complained to Bulman about how difficult it was working under politically driven Nazis who failed to understand what he was doing. He was convinced his unimpressed attitude toward them was going to get him fired and he was right. He was quickly snatched up by BMW who made him the head of piston engine development, where he oversaw the development of the legendary BMW-801 14 cylinder radial which powered many Luftwaffe aircraft, including the venerable Focke-Wulf FW-190A series. This engine may have been the first to include a mechanical computer, the 'Kommandogerat' which automatically managed propeller pitch, mixture (and spark advance?) which freed a hard-pressed fighter pilot from having to deal with engine settings while trying to score victories and stay alive.
Power, weight and Fuel:
During the Battle of Britain...
The DB-601A displaced 33.9L (2,069 cu in), developed 1,007 kW (1350hp) and weighed 660 kg (1,455 lb) with 6.9:1 compression ratio, for a power to weight ratio of 0.928 hp/lb, using B4 fuel of roughly 87 octane equivalent fuel.
The Rolls Royce Merlin III displaced 27.04L (2,069 cu iin), developed 775 kW (1030hp) and weighed 624 kg (1,375 lb) with 6.1:1 compression ratio, for a power to weight ratio of 0.749 hp/lb, using 87 octane fuel. It didn't take long for the RAF to upgrade to 100 octane rated fuel, improving the Merlin's output to 860 kW (1150 hp), but the development of high octane equivalent fuel in Germany was accomplished by a complex combination of additives derived from coal hydrogenation with lower octane equivalent B4 type fuel, which arrived after the Battle of Britain.
So although the DB-601A displaced more than 25% than the Merlin III, it weighed only 6% more and when both used ~87 octane fuel it delivered a 31% higher maximum power.
At the National Air ans Space Museum Smithsonian campus there is a Merlin on display behind a description claiming (as I recall) it delivered the highest hp output per cu in displacement of any WW2 V12 inline engine. However we can see above that there is more than one specification one needs to know when comparing engines.
Coolant temperature:
The Rolls Royce Merlin did operate at a higher coolant temperature than the DB-601.
The higher 120C coolant temperature of the Merlin compared with the 90C equivalent of the DB-601 meant that the frontal area of the Merlin's radiators could be less, causing less parasite drag and permitting higher aircraft speed. To make this work, Rolls Royce had to develop lightweight plumbing and radiators that could withstand both the high pressure and temperature of the coolant.Willi Messerschmitt complained about this to Daimler-Benz but to no avail.
Part of the reason may have been Germany's lack of strategic metals like nickel, chromium, copper, vanadium and others that were needed to make ideal high temperature alloys. Their metallurgists knew how, but the materials were not available in quantity while Allied engine builders could draw and ore from the natural resources of the entire British Empire and the United States. This also compromised Germany's gas turbines, which suffered serious engine life, reliability and logistical support issues. To me it speaks volumes about the quality of that Germany's overworked engineers that they were able to produce such competitive engines in spite of this.
Direct Fuel Injection:
Oddly the otherwise astute British examined the concept of direct fuel injection in the 1930s but discarded it as offering no advantage over carburetor induction. Germany's engine designers would cause them to regret that decision. The Bosch direct injection systems in the Daimler-Benz engines offered a number of advantages, some of which were not obvious...
Unlike carburetors which regulated fuel flow with float chambers, direct fuel injection systems were not affected by G-forces.
A Bf-109 pilot with a Spitfire on his tail could shove the sick forward and try diving full throttle to safety knowing his DB-601 will give full power.
A Spitfire pilot with a Bf-109 on his tail could not do that - the negative G forces would close the float valve in his Merlin's carburetor perhaps stalling the engine at a very bad time. He had to roll upside down first.
The Bf-109 was designed from the outset as a short range interceptor to be used as part of Blitzkreig warfare. It then found itself having to escort bombers across the Channel during the BoB, for which it lacked range. Limited to 87-90 octane equivalent fuel, it had a larger displacement than the Merlin and although it offered a comparable or better power to weight ratio, it had to burn fuel at a faster rate than did the Merlin to output comparable power. Direct fuel injection ensured the maximum possible efficiency of fuel usage. For each cylinder, the precise amount of fuel required was injected at exactly the right instant for the right duration, limiting waste. The range of the Bf-109 would have been even shorter had it not been for direct fuel injection.
Direct injection meant that the inlet manifolds carried only air, not an air-fuel mix. The closing of the inlet and exhaust valves overlapped, leaving a brief period where both were open at the end of the exhaust stroke. This meant that air from the inlet manifold briefly passed through the cylinder and out the exhaust, helping to cool the block, head and exhaust valves reducing the chance of knocking due to a hot engine. Because of the aforementioned shortage of strategic metals, preventing excessive engine temperature was always an issue with the Daimler-Benz engines.
Excellent video Francis - fabulous graphics that make normally obscure details much easier to understand. It would be a great companion to Douglas' book.
I was investigating whether I should try modeling and animating a DB-601 myself, but you've done it!
I wonder if it's possible to export solid geo files from Solidworks to Houdini?
Thanks again!
(Continued in the Reply....)
(Continued from above...)
Supercharger:
What we call combustion is the oxidation of a hydrocarbon like octane to carbon dioxide plus water (or as close as possible). 25 Oxygen molecules are required to oxidize every 2 octane molecules. Engine power is just as dependent on oxygen as it is on fuel. As an aircraft climbs, the the density of air (which is ~21% oxygen) falls off, which means the oxygen falls off and an engine which developed 1500 hp on the ground might only develop 1000 hp or less at 20,000 ft. As explained in the video, the object of an aircraft engine supercharger is to minimize the loss of sea level engine power at higher altitude. Compressing the air gets more oxygen molecules into the cylinder, so more fuel can be burned and more power delivered to the propeller.
Superchargers are rated to work best at a specific altitude, above which their effect declines and power falls off again.
Adding extra air pressure and thus combustion charge at sea level where there was already plenty of oxygen would likely destroy the engine. Before the DB-601 the supercharger had to be disabled until the aircraft climbed to somewhere near rated altitude, during which the pilot had to live with declining engine power. Once they were close enough to rated altitude they could safely engage the supercharger and enjoy full engine power again or something like it.
Dr-Ing Karl Kollmann's supercharger for the DB-601 changed that.
As I understand it, the supercharger could be left on for the whole flight. The engine charge was based on altitude constantly being adjusted by an aneroid barometer which drove a fluid coupling similar to a car automatic transmission torque converter between the supercharger impeller and the engine to deliver the ideal charge for a given altitude. At ground level the supercharger ran but delivered very little charge (which is why DB-601 and 605 engines have a distinct whine or whistle near the ground). As the aircraft climbed, the charge was automatically increased to ensure the engine could always deliver maximum power output all the way to supercharger rated altitude. Beyond that, power started to fall off again, like a conventional supercharger. IMHO, this was an inspired piece of work.
The DB-610
Yes 2 x DB-605 coupled via a common gearbox was called a DB-610, but before that 2 x DB-601 coupled likewise was the DB-606.
The DB-606 was a complete disaster - responsible for the deaths of many Luftwaffe bomber crews. It was a nifty way of stuffing 2 engines into a small space mostly within the wing that caused lass parasite drag than 2 separate engine nacelles but it came with major problems, the biggest of which was its tendency to catch fire. The DB-606 had worked well in the high speed prewar Heinkel He-119 experimental prototype bomber/reconnaissance aircraft but it turned out to be disastrous for the Heinkel-177A heavy bomber causing catastrophic fires to such an extent that their crews refused to fly them. The DB-610 was definitely an improvement but coupled engines were always a stopgap measure. This very nearly ruined Heinkel and amongst other things caused them to cancel their He-280 jet fighter because they simply didn't have the engineering staff put out the fires in the He-177A program while further developing what was the first jet fighter to fly.
As an aside, it's interesting to compare the He-177A with the Avro Manchester which also came with unreliable high powered Rolls Royce Vulture engines. The British Air Ministry cancelled the Manchester but allowed Avro to design a new version powered by 4 separate Rolls Royce Merlins and the result was the Lancaster. Heinkel (according to his autobiography) was forced to make the He-177A work with coupled engines even when he offered a more conventional version. The same air-frame fitted with 4 x DB-603 engines (secretly in Heinkels Vienna-Schwekat plant where the RLM couldn't see it) and the He-274 built by Farman in occupied France with the same air-frame and 4 separate engines proved how sound the He-177 air-frame design had been all along. Thanks to the DB-606 and DB-610 and the RLM, Germany was denied a potentially first class heavy bomber as well as a jet fighter alternative.
The real problem was Germany's inability to develop a reliable high power engine like the big American Wright and Pratt and Whitney radials or the British Napier Sabre.
They just didn't have enough engineers to both oversee production of current engines to meet wartime demands plus develop new ones. Government oversight of engine development by the RLM was nowhere near as good as it was in Britain and a great deal of time and resources were expended for no useful contribution to the war. The promising Daimler-Benz DB-604 24 cylinder X configuration engine was cancelled while rival Jumo-222 4 x 6 24 cylinder engine ran into conflicting RLM demands along with technical challenges with too few engineers available to deal with them. When it finally started entering service in late 1944 it was unreliable and clearly not yet ready.
----
Anyone interested in WW2 German or British propeller engines really must read The Secret Horsepower Race by Calum Douglas. It's a brilliant book written by an F1 racing engine designer who also speaks German, who spent 5 years researching and writing the book based on archived wartime official documents. He also managed to acquire the original notes and documentation of the late Dr-Ing Karl Kohllmann - who with Dipl-Ing Fritz Nallinger was one of the chief designers of the DB-600, 601, 605, 603 engine family. He also separately translated a paper Kohlmann wrote about the theory and practice of engine supercharging. The Secret Horsepower Race is a super-detailed, well written and illustrated book that includes so many fascinating stories about how and why these engines became what they were.
www.calum-douglas.com/
Excellent video Francis - fabulous graphics that make normally obscure details much easier to understand. It would be a great companion to Douglas' book.
I was investigating whether I should try modeling and animating a DB-601 myself, but you've done it!
I wonder if it's possible to export solid geo files from Solidworks to Houdini?
Thanks again!
@@tsegulin DOHC 4 valve engines takes up a lot of space and are heavy. A big block Chevy push rod fit straight in to Porsche 928 replacing a 5l. A 6l small block Chevy can replace a 5.3l jeg V12 in a XJS and the Chevy weight much less. I wonder how much displacement one could get in a "Chevy V12" aircraft engine within the space comfines of a RR Merlin. 45 liters? 2 large valve is not that big of a handicap in a supercharged low reving engine.
You have an error, you list the cubic inch for both rolls royce merlin and db-601 as the same but you have their liter displacements as different. If the cubic inch displacement is the same for both then so would their liter displacement. So something is wrong here. @tsegulin
@@JuniorJunison
You are correct, the cu in displacements of the two engines are not the same.
DB 601 should read 2069 cu in
Rolls Royce Merlin should read 1,650 cu in.
The metric displacements are correct. Sorry, my bad.
@@tsegulin no worries
I'm impressed. This engine epitomizes elegant design.
I just completed a restoration of a 57 Mercedes 300sl with the direct injection adapted from these engines. Absolutely amazing technology for the era.
Lucky guy, very nice car. I've got a mk2 Cosworth Escort, but a 300sl would be a dream car.
Makes u wonder why direct injection wasnt standardized in cars in the 60s. Instead we got carbs way into the mid 80s.
Cool, I guess they simplified a little the injector as it didn't need to compensate for altitude anymore
@@datvik7187 This certainly has to do with the complexity of the design and therefore the high cost of production.
For this reason, NASCAR race cars still run with carburetors by regulation. This is also just to keep costs down.
@@christophermikrowelle7093 It's my opinion that Mercedes could have absorbed the costs in their R&D. After all, they charge a premium for their cars, not to mention they LOVE making complex systems in their cars.
Actually, the original steam engines had the cylinders at the bottom and crank or beam above so this V12 is "right-side-up". When engineers decided to put the cylinders on top and crank at the bottom, they were called "inverted" engines, which became the norm.
So it's actually an inverted-inverted engine 😉
@@starsiegeplayerso when flying inverted - it's an inverted - inverted - inverted ?
@JollySchwaggermann at that point it comes full circle and reverts back into a medieval watermill
They didn't run wet sumps however
@@kingcosworth2643 No, just drip-lubrication with oil-cups and greasers climbing all over them with oil-cans. I think you'd have to have quite tiny midgets lubricating this V12 ;P
I remember a video where a guy sent a DB601 crankshaft into RR to have it measured and checked. The engineer at RR said the specs were spot on to its very high tolerances He said don't drop it because they couldn't make another like it the tolerances were so exact with their modern equipment. Imagine they were doing this in the thousands under constant bombing of their factories.😮
The machining of the P&W 2800 was so precise that there was no gaskets between the engine block halves. The Germans were astounded by the quality of those engines. Some of the generals knew they were going to lose because of Americas industrial strength.
@johnarnold893
This isn’t particularly impressive. Most aircraft engines don’t use gaskets between the crankcase halves because unlike automotive engines the main bearings are incorporated into the crankcase and don’t have separate caps. If they used a gasket the preload would change as it compressed or expanded leading to a spun bearing or catastrophic failure of the through studs that hold the combustion forces.
They typically use a silk string to act as a gasket.
@@johnarnold893 wanker
This story is repeated of just about every WW2 era engine being examined by another manufacturer, it's so old it has hairs on it whether it's Pratt & Whitney, RR, DB601, Merlin or whatever.
Those engines were made with fixed jigs and tooling rather than CAD/CAM/CNC. Making the jigs and tools, providing the sharpening and adjustment data etc. only makes sense if you are tooling for large numbers. Bombing factories in WW2 was so imprecise that it was rare for tools and machines to be hit, and in any case there would typically be multiples on the production line.
The cost of doing the metrology on a DB601 crank, then feeding it through to the program and tooling, would also be uneconomic for a single crank. Making it from billet would involve a great deal of machining, forging it would add to the tooling cost. You would also probably need to have details of the alloy in use and its heat treatment, which would involve testing the sample crank in different places for hardness, ductility and modulus.
The 1940s engineering was as good as it could be but today we could easily design and make better engines - the reason we don't is that whole economy of scale thing, no new piston aero engines because the production volume wouldn't justify the sunk costs before production started.
@@johnarnold893 The industrial strength was quantity not performance. Individual German tanks, guns and aircraft were often better than Allied ones but could only be made in small quantities (indeed the main benefit of bombing Germany seems to have been the diversion of so much effort into producing the 88mm Flakcanone in volume.)
The German joke was that one Tiger could defeat ten Shermans but the Americans always seemed to have eleven Shermans.
Thanks for the video. According to a 109 pilot there was a valve to isolate the left or right radiator in case it was hit.
Well done. The cooling issues were covered well, didn't know about them until this.
Missed out that the boiling point would drop with increased altitude. The system would become pressurised anyway.
Waking up to this was an unexpected surprise. I never heard of a hydraulic supercharger and it's counterintuitive to me that higher compression ratios are better for fuel economy. Very interesting and informative.
This is my first comprehensive look at the Messerschmitt BF 109 engine after learning about it decades ago.
at rarer air bars its often not even a choice - less fuel is needed for the same net thrust provided you find a way to have the chamber bars higher, hence supercharger
@@TheGrimStoic Thank you very much, I learned something new today.
@@bobhill3941 nothing you didn't already know, c'mon. I just applied it for you.
@@bobhill3941 nothing you didn't already know, c'mon. I merely summarized it for you.
Higher compression engines paired with higher octane fuels and part-throttle operation makes for improved fuel economy when maintaining a constant cruising speed. It's about sipping the good stuff for power.
First time I watch one of your videos. Been an engine nut since childhood, and this answered many questions I had. Very good work sir.
Technical yet very clear. Thanks, I've always wondered why the German V-12 was inverted when no Allied engine maker tried this. Lots of stuff in there I didn't even know I didn't know!
Both de Havilland (UK) and Ranger (USA) made inverted engines. They were air-cooled, so they were smaller than the DB series.
@@muzza881 Interesting. Thanks.
Ok, let me see if i get this right...... It's a 33 liter 12 cylinder 2000 horse power engine with variable speed super charger, dry sump , high pressure direct cylinder fuel injection, inverted, multi- displacement, gear driven cam, nitrous oxide or methanol injected rated, 4 valve dual over head roller rocker valve train,dual ignition system, roller bearing connecting forged rods, that only weighs 1300 pounds and yeah you can shoot a cannon thru it while its running and it was designed in the 1930s ??????!!!!! I feel like engine designers nowadays need to stop bragging.
Thank you I have wondered about this configuration & now I know
I can imagine these engines consumed huge amounts of oil. I had a BMW motorcycle where the engine was flat on it's side and when you parked it on the kickstand the "top" side was angled slightly downward. Every single time you parked the engine there was oil seeping past the rings into the combustion chamber and there was ALWAYS white smoke on startup - LOTS of white smoke on cold starts in the morning.
K 100 or K75??? The "Rolling Bricks"......
@@Wuestenkarsten R65
@@PeterRoberts-imogiri Ok, so the ""old" Air cooled Boxer Engine. Nice and nowadays hard to get!
yea my goldwing does the same.
Oil leakage causing detonation, and fuel diluting the oil, were problems with the DB series.
The original Zündapp boxer motorcycle had a cylinder angle of, I think, 170 degrees or even less, so that the oil would drain back, at least in sidecar form. In my view BMW should have gone for a wide angle V. The difference in vibration wouldn't have been much, though it would be on the rather silly huge boxer they are now making.
Really nice animations, makes everything quick to understand. What a marvel of engineering!
I've watched another video on this engine, but this, by far, was much more informative, You've gained another subscriber.
Great video bro, really informative and well put together keep up the good work
11:36 Fiat?! That's a Rába Bf-109G-2 Built by Rába in Győr, Hungary under license. That is NOT an Italian Bf-109.
Fiat and Alfa-Romeo built the engines under license to domestic Italian Fighters, like the Macchi C.201, Reggiane Re.2001.
Kawasaki and Aichi both recieved the license, because Japan had a severe interservice rivalry, and the Navy and Army would not want to share an engine, or aircraft. Aichi produced for the Navy, and Kawasaki produced it for the Army.
The other thing you missed is that Germany didn't have a fuel shortage when the engine was developed, the Injection was specifically developed for manuvering advantage, and the MW-50 injection was used for energy traps as well, since with the extra power, they could actually have both the horsepower, and airframe advantage over the P-51D.
The inverted design was sought after specifically for leaving more space over the engine, enabling the installation of machine guns, and giving better visibility for the pilot.
It wasn't a fuel shortage, it was their inability to produce high octane fuel.
@@dougerrohmerIt wasn't an inability to make high octane fuel, it was the inability to make enough high octane fuel--actually, enough of any fuel--to meet it's constantly increasing needs.
High octane fuels were available prewar, viz. speed record attempts. DB 601N engines used C3 high octane fuel in 1940, and, by late '41 all FW-190's used C3 for their BMW 801D's until the end of the war.
@@josephstabile9154 It was more an inability to make enough of ANY fuel by the end of '44.
The power and rpm figures are manifestly wrong. The engine produced 1000 PS at 2300 RPM and 1.3 Ata and 1100 PS at 2400 RPM and 1.4 Ata (according to the engine tech-manual for the DB-601 A). The N-Model (DB 601 N) allowed up to 2800 RPM at 1.4 ATA and produced 1280 PS. The inverted configuration and the way the piston sprayed the oil in the crankcase produced problems with foaming at high RPM, thus the later DB engines were all fitted with defoaming devices to allow higher RPM in the DB601, 605 and 603. Also the DB601 didn't have a pressurized cooling system (the DB605 had).
Great video
An extra advantage of the inverted engine was that the distance from the crankshaft to the upper surface (piston case or what would have been the sump) is reduced. Since the distance from the that to the upper fuselage is driven by allowing the pilot to see forwards, the plane could have reduced frontal area. I didn't describe that well- hope you can understand it.
The Merlin and Allison engines used a water/ethylene glycol mix to allow higher temperature coolants, and thus smaller radiators, without requiring a highly pressurised system. It ran at about 120C. I wonder why the Germans didn't try that approach. Maybe they just didn't have the capacity (the British got their ethylene glycol from the USA).
Incidentally, there were bf109s with V12 engines the "right way up" in the form of the Spanish licence-built Hispano Aviación HA-1112. However, the Germans could not provide the DB605A engines as they needed all they could build once WW II started. Consequently, the Spanish installed the Hispano-Suiza 12Z V12, which was similar capacity (36.5 litres) and had the same provision for a hollow propeller shaft to accommodate a cannon barrel.
After WW II, when surplus Merlin engines became available, then those were retro-fitted to the Hispano Aviación HA-1112 fighters. They can be seen in the film Battle of Britain, as the producers leased a number of those Hispano Aviación HA-1112 fighters and painted them up as Battle of Britain era bf109s. However, you can clearly see the give-away that they were Merlin engined from the higher line of the exhaust stubs. They would also, of course, not have sounded like a DB605A engine either, but the producers just dubbed the "correct" sound in.
So to what extent the adoption of a conventionally orientated V12 affected the performance and flight dynamics of the bf109, I really don't know. But clearly the inverted engine format wasn't absolutely essential.
@@EbenBransome The Merlin I, II, and III series all used pure ethylene glycol coolants. That presented problems, not least with it being highly inflammable. From the Merlin X on, a water/ethylene glycol mixture at a ration of 70:30 was used, and that seems to have remained.
First it is a fact that RR used a water/ethylene glycol mix an settled on a ration of 70:30 as the best compromise (which they used from the Merlin X onwards). Also, the lower heat capacity of ethylene-glycol does not, in itself, cause radiators (or rather heat exchangers) to be larger. Quite the opposite as they can run hotter and exchange more heat through a given surface area. Where the reduced heat capacity of ethlylene glycol does come into play is in how fast the flow rate has to be. One half the heat capacity, then twice times the flow rate and there are also some conduction issues.
The prescribed coolant temperature at high power output levels, such as when climbing fast and in combat was 120C, although some later models were allowed very short periods at 135C.
In practice, the cooling system of the Merlin and its prototypes evolved quite a lot. Originally it was intended to use evaporative cooling, but it proved unreliable and hence the move to ethylene glycol cooling in the earlier engines. Later it move to the water/ethylene glycol mix.
@@TheEulerID Your explanation is correct. I deleted rather than editing my original post for better clarity.
I do take some issue with your other statements. Because of the greater viscosity of glycol, attention has to be paid to the flow paths especially in the cylinder head. But also high glycol mixtures have more wall adhesion in heat exchangers than straight water, so more circulating power is needed.
The db 610 sounds like an absolute nightmare to service
@TheEulerID Thanks so much for your reply, it was informative and fascinating. I knew of diesel being more power dense because of it being less refined.
My reasoning was that, the first thing manufacturers did during the first U.S oil crisis in 1973-74 to improve fuel economy was to lower compression.
I learned so much from your reply.
Did anyone else notice that the propeller blades were pitched backwards. In the animation of them rotating, they would be pushing the air in the wrong direction.
You should look into the Napier Saber engines. They are a wonderful and slightly weird engine that uses sleeves instead of valves to exhaust and intake air.
Napier were pretty crap at sleeve valves. It was Bristol who perfected them and made them in volume, they had to help Napier with the sleeve design and manufacturing.
The Bristol Centaurus produced about as much power as the double Daimler engine, from 18 cylinders. But by the time they were fully developed they were heading for obsolescence.
I believe the Napier engine used in the Hawker Typhoon had a service life of just 23 hours..is this correct?
@Kenneth-p1b The early Sabres had a host of faults including unforgivably poor quality control. It took Bristol to fix the sleeves and the EE takeover to get some shop floor discipline.
I believe the common American belief that they productionised the Merlin and early examples they saw were handmade was confusion with a couple of Sabre samples sent to the US which had indeed been hand finished. RR was set up to produce Merlin engines in volume from the start.
I love the centrifugal compressor swirl.
Best Engine Ever made I want one so badly
Thanks!
Thanks. I truly appreciate it.
Always wondered how they managed oil in those. Now I know!!!!
Thank you!
10:38 Interesting fact: To beat early marks of Spitfire that were chasing them, Luftwaffe pilots would put their Bf 109 into a steep dive. As the negative g force would starve the Spitfires carburettor of fuel. The fuel injection of the Bf 109 wasn’t affected by g forces.
Funny that porsche used a similar con rod while developing v rod for harley davudson.
Fantastic video, descriptive and informative. Nicely put together!
Finally a comprehensive breakdown.
Stunning and well presented animation and explanation! Subbed.
A great video idea would be about AG and AX engines from the 1900s to 1930 or 1920s and how they work.
*DUDE THAT WAS FANTASTIC* You got a sub...!!!
Answer is easy and no mystery: a V engine upside down puts the small end of the engine up, allowing for a narrower canopy, hereby increasing visibility for pilots by a big margin. Recall the "hun out of the sun"? German pilots were able to spot their enemies much earlier
Hun in the sun was an expression used in the First World War. At dawn the Hun attacked from the East with the rising Sun behind them making it difficult for the British and French forces to see the enemy due to being dazzled. Nothing to do with the shape of the engine.
@@philhawley1219 Nope. WW II RAF warning
Everything is very clearly and neatly laid out, I just noticed that either the propeller is rotating in the wrong direction in the entire video material, or the angle of the blades in the direction of the aircraft's movement is incorrect
Tower Shafts and bevel gears were standard for inline aircraft engines. Gears also drove the magnetos, oil pumps, foolant pumps and mechanical superchargers. Botton end bearings could be plain or roller type. Radials it was common to use ball bearings on the crank. The cam rings were driven by external and internal spur gears. The cam ring in an 18 cylinder radial often turned wt 25% of crank speed. Props in all engines except low powered direct drive engines used speed reduction drives to keep prop tip blade speeds below the speed of sound.
What's the firing order of this engine?
@1:57 "if the engine was stopped for a long time, the cylinders could become flooded with oil and the spark plugs had to be removed and cleaned." No, that isn't the main reason, and that is why this video was definitively not written by any airplane mechanic. If oil gets into the cylinder and the engine is rotated by a starter without draining the oil first, the rods will bend (fluids don't compress) and the motor will have to be rebuilt. This is called hydraulicing by most mechanics. That is probably the main reason that the Allies didn't want to use an inverted V-12, because it was so easy to hydraulic the motor. It may have required that the spark plugs be cleaned, but the main reason was the hydraulicing that would damage the motor. This is why you don't just start an engine that has ingested water - it will destroy the engine. You have to pull all the spark plugs and spin the motor over to force all the water out of the cylinders. If you've ever wondered why you have to pull the prop through two revolutions on a radial - this is why. You have to get the oil out of the bottom cylinders before spinning the engine over.
He was referring to removing the spark plugs to drain the oil and also cleaning the spark plugs as a secondary thing, obviously the main thing is to drain the oil through the spark plug holes.
Whew! Imagine if this type ingenuity had been applied to peace instead of war? Bummer!
This design brought with it a lot of positives as the video explains. I learned some facts about this engine today. Thank you for posting this!!
Because of the fuel injection it was possible to keep both intake and exhaust valves open for a certain time. This increased the gas exchange in the cylinders.
All this AMAZING outstanding tech in the 30s/40s WAY ahead of the time imo
You did an awesome animation job..
In these inverted engines, how did oil from the crankshaft or the under sides of the pistons get back into the oil system, and not try to drain past the rings towards the combustion chamber?
Great Job! Thanks
Very well done !! An upside down engine for airplanes they used was brilliant, and I wonder why more countries did not use it. The mechanical injection had issues, but it worked! It was stupid the way England slaved themselves to carb's even with the choke point regulator hack.
A few minor points to mention: Germany never seem to master the high pressure coolant problem, compared to the British and Americans. They always had issues with it, and many engines only lasted 14-20 hours. Germany's main fuel and lubricant sources was coal converted to low grade fuel. They never got over 80-90 octane, where England and America eventually got up to 130 octane. The NITROUS OXIDE was Germany's secredt weapon! And it took YEARS for England and America to figure it out. Although water injection to cool the cylinders was an old racing hack. The Turbo's - and Nitrous - LOVED low compression ratio's and that worked out very well. The dual engine concept never really worked out.
Dual sparkplugs another brilliant idea, you are right, they needed to be opposite or further apart. Kawasaki cruiser motorcycle still use this concept today!
"why would someone join two engines together to reach incredible power values that exceed 3000hp?"
This is a flawed "question"
Because there wasn't enough time to join 4 😂
Nothing in America or England Japan or Russia could compare. An elegant design concept made complete with great engineering & problem solving...
Actually, much in U.S. & England compared very favorably.
What this video did NOT tell you was the rapid, steadily decreasing decline as of 1940 forward of German alloy quality due to inability to acquire sufficient strategic metals for their production requirements: manganese, chromium, nickel, moybdenum, copper, aluminum, vanadium, cobalt, tungsten--even high quality Iron ores. More exotic metals like platinum, beryliium, indium were out of the question. That's why there were unending problems with their engines, such as valves that burned & corroded causing detonation, spark plugs that would not last, and non-competitive lead-babbit bearings that could not endure high boost pressures and corrosive fuels. You ever notice grainy quality of German WWII film? Yeah, even silver was in short supply. And not enough chromium to produce stainless steel. They were working at an alarming strategic material disadvantage, and, unlike US or USSR, could not compensate with higher production capacity than their adversaries.
@@josephstabile9154 Also the Germans had a shortage of skilled workers, then a shortage of semi- skilled workers and eventually even resorted to slave workers who took every opportunity to sabotage whatever they were forced to make for their oppressors.
@@Willheheckaslike If I correctly follow you, you're asking about the 60 Series RR Merlin, that is to say, the 2-stage supercharged Series, as used in the Mk IX (and others) Spitfires. This engine allowed higher boost pressures, ultimately (late '44/'45) in the range tof 72" hg with 150 octane avgas, famously in the Packard Merlin equipped P-51D. As the British were striving to keep the Merlin competitive, especially during the crucial time of the introduction of more advanced models of the Bf-109, and of the FW-190, the USA was of great help with its advanced silver/aluminum/indium bearing technology, and its iridium electrode spark plugs. These technologies were what allowed the Merlin to be able to endure the much boosts pressures that 2-stage compressors, intercoolers & high octane promised. Implied in that, the necessary strategic materials/exotic alloys were available to the USA, and therefore to Britain. Germany, after '40, had to increasingly restrict its industry's use of these materials, some of which it never had access. By mid '44, the lack of alloying materials was so severe that German armor was developing unacceptable levels of cracking upon impacts, and transmissions/gears were also failing at higher levels. Some of this can be attributed to falling/rushed production standards, but mostly to lack of strategic materials. To quote Albert Speer, by end of April '45, the total amount of strategic ores remaining in Germany could be enclosed in a broom closet.
The final versions of the Merlin and Griffon did more with less. The German problem was their eternal one - complicate, don't develop as such.
You are right, they did not compare. The same displacement RR Griffon had superior metallurgy, superior supercharging, massively longer engine life and 50% more power. It’s hard to be a Wëhräböö in grown up discussions.
I’m already amazed by the timing systems to be able to fire through the propeller arc. Whoever decided to yeet a 30 mm through the engine was definitely thinking outside the box.
It wasn’t that crazy an idea, since the Russians and Americans also made cannons that shoot through the engine (even bigger ones like 37mm)
Brilliant. Super erklärt 🧐👌
great work - best explanation I have seen of this unusual engine geometry
Adding 2 engines for the DB610 reminds me of the video talking about the differential. In order to increase the engine output, we will put in ... MORE engines.
Well done! Most sources just say, "Well, uh, moves the engine out of the pilot's line of sight and allows through-the-prop and top gun placement. You dove MUCH deeper!
The video was called Inverted V12 WHY?!?. It's a pretty good video, but most of the info was not about WHY!?!? Inverted V12, it was technical information about HOW?!?! this V12. So yeah he dove deeper into HOW!?!? but not into WHY!?!?, which really boils down to aircraft geometry. It's not like you can't have a supercharger or fuel injection on other engines.
Can i ask?
What software do you use to animate and model these aninations?
Sure. It's solidworks.
@@repairman22 thanks for telling me that
I can just about change the oil on an engine i am not a motor head, however the engineering and technology involved in this 1940's engine is facinating, infact incredible
Nice work with all the CAD modelling and animations!
You left out a tiny detail on the DB 610 - it had a real nasty habit of catching on fire. the sole reason the HE-177 was apiece of flaming crap. Great animations!
I really enjoied the video. I live learning about this stuf but you may want to change the direction the prop turns or the pitch of the blades. Currently the prop is blowing the air backwards.
Thanks for the video!
07:29 If the engine will be operating at higher temp, then the radiators have to be BIGGER, NOT SMALLER. That sounds backwards.
You have to consider the differential in temperature between ambient and the radiator. All things the same a hotter radiator will dissipate more heat than a radiator at a lower temperature, that's just basic heat exchanger stuff. That would let the radiator be smaller as well as the fact that it doesn't even need to cool the coolant as much since it is supposed to run hotter. Makes perfect sense, besides running an engine above 212 degrees being really, really infeasible...
No, that is completely wrong. If the radiator is running at a higher temperature, then the temperature gradient is higher which means the rate of heat transfer per unit area is higher. Thus if the radiator (really better called a heat exchanger) runs at a higher temperature it can be smaller and requires less air per unit energy transferred.
Excellent graphics!
Another video comparing the Merlin with the DB601 would be good. At the beginning of the war the 2 opposing engines had near identical output and the respective aircraft Bf 109E and Spitfire Mk 1 had near identical performance. As the war progressed the DB 601 started to fall behind as did later models of the Bf109.
You read my mind what I have always wanted to see in DB600..
Very instructional video. Thanks for creating it.
always wondered how the oiling system worked on this, thanks for the explanation.
There's an excellent by Calum Douglas, 'The secret horsepower race' that provides tons of detail on WW2 engine development including the DB engines.
Excellent video, well done! Thank you!!
German Engineering at it's finest....I learned a little more about this engine. So cool!!!
Great illustrations and well written text!
These are excellent !!!!
I volunteer for an aviation museum and would love to see one to help explain the WWI Rotary engines like the LeRhone.
this is an excellent video. truly one of my favourites
I didn't really get that crucial advantage of up side down cylinders. But troubles with spark plugs and hydro locking - obvious down side. It seems like no one else used that layout at the time
Excellent video very well done and I definitely learned something.
I just wanted to tell you that I subscribed to your channel and I like your channel because I like it very much because it is shown it with a video and all I like features in the morning and the evening and in the morning to then I was watching videos so it's a nice show and always see individual played at the TH-cam channel here I can subscribe where it is awesome to see how it is done from the engine to see it when it's rotating and the opposite side with the cylinders with two spark plugs I didn't know that and that's awesome to see when there is a spark plug on the other side but the next to each other then again I would like to say this is an awesome video
Can you make a video about the Mercedes OM617 5 cylinder turbodiesel?
great video on a fantastic engine , just subscribed
Did these needed proped over before starting as did radials?
That airplane was a well designed well thought out piece of engineering.
Alison (US Aircraft) Coupled two of their V-1710's together also. This is the very rare V-3420 (although technically it was a "W" engine just like the DB. It was never quite perfected, and with the advent of British Jet Engines, Alison stopped the program entirely,.
However, the "V-3420" drove a fancy gearbox that turned Counterrotating Propellers, which was a fad for awhile. In my opinion only the British got this right... In all but a very few cases, instead of a Huge Engine driving a complex gearbox (which was the source of most of the failure that almost always resulted in a crash*), they went with (most of the time) with two standard engines per Counter-rotating propeller set! Each driving it's own propeller to achieve the same counter rotating affect!
*like the Hughes XF-11 crash after a gearbox failure cause the right hand propeller set change the pitch with one propeller going into full reverse thrust and the other went to fine pitch (which produce very little forward thrust. Just before Howard Hughes got to a golf course, the forward propeller went to zero thrust and this, along with other factors caused the crash that nearly killed H.H.!
Excellent Explanation 👍🙏
I'm liking your videos. New subscriber! :)
Thank you for this educational video! I admire your work! I'm sure it takes a lot of time for 3D modeling and gathering informatio!
That was excellent. The best I have seen.
Nice video bro
cool vid man! really well done
The lower C of G is a myth, if the cannon tube is on the planes centre line, then the heavy crank and rods are now above the planes centre line.(In cars there are no inverted V engines to keep the C of G low) The higher C of G of this engine helps the plane to initiate a roll from straight and level.
2:55 why would needle roller bearing allow an aircraft to operate without oil? I don't see any connection.
Plain bearings are 100% dependent on oil. Roller bearings too, but as they have "wheels", they can last longer without oil. In both cases, the bearings will be siezed, but the roller bearing will last longer. In fact, plain bearings produce less friction than roller bearings as long as they have enough oil pressure.
It’s to mount weapons in the nose of an aircraft. The oil pan up top allows for more room for guns closer to the line of sight of the pilot and the sights themselves.
verrry interesting , never hear about the close to perfect ger. engeniering me engine ....perfect animatiton too
How did the prevent oil leasing in the cylinders hydro locking the pistons when cold starting
It's a dry sump design. That is as much of the oil as possible is scavenged out of the crankcase and stored in a separate tank. That's not unusual - all the high performance V engines in WW II were dry-sumped or else there was a very strong chance of oil starvation under aerobatic manoeuvres.
That's not to say it isn't still possible. In the case of radial engines it was normal to turn the engines by hand first to ensure that the bottom cylinders weren't hydro-locked. I suspect the Germans may have done that with their inverted engine designs too.
The inverted aircraft engine wasn't an idea of Daimler-Benz, it was a requirement of the Air Ministry for Air Force Engines. For this reason, the majority of German V-Engines for aircraft during WWII were inverted, Argus AS 10/410/411, Junkers Jumo 210/211/213, DB 603/605.
It appears that one of the main reasons for this requirement was easier maintenance. Because, the mechanics could perform most of the work from below the engines.
Never ceases to amaze me how smart people were even in those days.
I have to admit, I do like the looks of the German Stuka but the P51 mustang is my ultimate favorite fighter of old. Today it’s the A10 followed by a close second is the F22 then F15.
Old aircraft internal combustion engines are so fascinating.
Modern ICE are interesting too
Incredibly well done thanks!!!!
Which animation/CAD Tool are you using?
Finnish Air Force had some problems with crankshaft lubrication on DB605's. Late engines had only bare iron cylinders, they wore fast.
It was an issue on all early DB 605's. When they developed the 601 into the 605 they switched from roller bearings to plain journal bearings on the crankshaft, but forgot to increase the oil supply. Doh! Eventually the increased the capacity of the oil pumps, introduced crankshaft nose oil supply, and a centrifuge to de-aerate the oil to reduce foaming. But all these fixes took quite some time.
this is flat out amazing. great work on the video. can you do one about rotary engines such as which was used in the nieuport 17? always wanted to know how they work. especially the fuel systems.