You've probably heard of a radial engine. They were the early powerhouse of aviation. But how do they work? Watch Boldmethod's latest video and find out.
The "two unaccounted for" were because they were so complicated that they were naturally very finicky, to the point that on virtually every mission, the B36 came back with at least one non-functioning engine. If you'd like to see a B36 on display, make a trip out to Tucson, AZ and visit the Pima Air and Space Museum. (No, I'm not associated with them. I just love aircraft.)
:20 4 Stroke Cycle: My dad taught the cycle as a teenager in a way I have been able to remember it easily with all the innuendo he could muster he told me the 4 strokes were Suck, Squeeze, Bang, Blow. Now every time I hear the 4 strokes mentioned it think back on that lesson.
On that Oshkosh flight line, don't forget about the WW-II fighters and trainers that also use radials! All the Grumman fighters (F4F, F6F, F7F, F8F), the Corsair, the PT-17, BT-13, AT-6, T-28, etc. On the German side, the FW-190. And more!
I'm not watching this video to see how 4 strokes work, I'm watching to see how such a strange engine type dealt with oil containment, engine balance, and uneven wear in the era before boxers!
Inverted engines, of which many thousands were made prior to and during WWII, had oil control issues to overcome for all cylinders, not just the lower cylinders as on radial engines. Radial engines, mostly in the form of rotary engines with the engine spinning around a fixed crankshaft, were common and extremely successful during WWI, so they are hardly "weird." All piston engines have the potential for balance problems with rotating and reciprocating parts, but the radial configuration is no worse than any other. And the myth of unequal piston wear due to orientation relative to gravity is just that. The moving parts of internal combustion engines are subjected to acceleration forces of such magnitude that the force of gravity is not even a rounding error in design.
Radials are "dry sump" meaning they have no oil pan. They instead have an oil tank, normally mounted on the firewall. There are pubs, likely on line which explains how the system works. Combination of pressure feed and spraying/slinging oil onto various components.
There is a very small collection sump and a scavenging pump to remove excess oil back to the reservoir tank, oil is pressure fed from the reservoir tank to the engine by another pump. Note that the cold start process for a radial always involves turning the motor slowly through 3-4 revolutions before attempting to start, this is because after sitting for some hours oil(and sometimes fuel or moisture) can settle in the downward angled cylinders seeping passed the piston rings into the combustion chamber and at the extreme cause a hydraulic lockup or more commonly it reduces chamber volume drastically increasing compression ratio and/or causing a hydraulic hammer(kind of like a garden hose with bubbles in it will splurt and pop and shake when you first turn the water on)
I wonder how they can fit 5 connecting rods to one lobe/throw on the crank, the would need to be really fine/thin in comparison to a car engine.... Am I missing something?
@@homewordbound4970 I see it has been some time and no one has answered. There is one rod in each bank called the master rod. The other articulated rods are pinned to the master rod at the circumference of the rod crank end. His video shows the motion but it is not explained. The explanation gets quite complicated after that. This system causes timing and stroke length errors that must be compensated for. Most engines have a compensated breaker cam in the magneto. The real part to understand is the cam ring. By a 4 lobe cam ring I mean four intake and four exhaust lobes. A nine cylinder can run with a 4 lobe cam at 1/8 engine speed in reverse rotation to engine rotation. It can also run with a 5 lobe cam ring at 1/10th engine speed in the same direction as engine rotation. If you want to draw it up start with a 3 cylinder. A single lobe will turn in reverse at half speed and a two lobe at quarter speed. If you take the time to understand the cam ring geometry you will also understand why there is an odd number of cylinders in a bank and the firing order is odd then even.
I've only seen a photos of a radial engine/on tv, it looks like the barrels/cylinders are arranged inline/level, I'm wondering how they managed to fit 5 connecting rods/big end bearings to the crank? I can only picture room for one unless the cylinders are slightly off? I've often wondered when I see them on TV, I'm a bit mechanically minded but I can't get my head around that? I'm watching Valkyrie and seen a radial so here I am trying to find out, I get the 4 stroke just can't picture the big end bearings arrangement for multiple pistons 🤔
@@homewordbound4970 The most common arrangement is a master rod/articulated rod arrangement. The crankshaft throw (in each row, for a multi-row engine) rotates a connecting rod with a piston on the other end as usual. This is the master rod. This rod has extended flanges with multiple holes drilled into them in a circular pattern, one hole for each of the other cylinders. Each hole has a pin in it. Each pin is inserted through the "big end" of a straight connecting rod which is retained between the two flanges of the master rod. The other end of each "articulated" rod, as they are known, is a "little end" through which the piston pin is inserted, so each articulated rod also drives one piston in its respective cylinder. Each articulated rod is free to rotate side-to-side enough to keep pointing at its cylinder as the crankshaft throw moves the entire master rod, and its captive pins for the articulated rods, in a circle. So, in a nine-cylinder engine, or row, you have one piston being moved directly by the master rod, and eight more pistons connected to the periphery of the master rod by articulated rods and moving them as the master rod circles the crankcase. There are complications in this arrangement due to the fact that the articulated rods do not move on the exact circumference of the circle described by the crankshaft throw, but these geometrical characteristics can be compensated satisfactorily.
The russians designed and developed a diesel radial that was water cool with 56 cylinders and made over of 4,000 hp. They even coupled 2 together in a package and that one makes over 10,000 hp. The engine series was so successful that they are even still in production today. They never did make it into any aircraft but they found a home in marine apllications.
Not that I have any credentials or actual knowledge, but I would assume efficiency is similar to that of "regular" piston engines like what you'd find in most cars
Their main benefit is that air cooling works really well for them, so you don't need a radiator. Also, they can usually still run even if one or two cylinders get shot off. Important for a warplane.
Initially yes, very much so. That's why radials were more common in WWI. Between the wars, advancements in liquid cooling made inline engines slightly more efficient for aircraft use, thus the introduction of Merlins and Allisons and what not. But then NACA and others did some serious research on things like cowl designs that reduced drag on radial installations enough to get them back up to inline levels of efficiency. Thus giving us P47s, Corsairs, FW-190s, etc.
There is no reason why a two-stroke radial engine could not be built. Such an engine would fire each cylinder in the order of rotation regardless of number of cylinders, odd or even, and would always have a balanced firing interval. The R-4360 Wasp Major had cooling issues only when stuffed backwards into the wing of the B-36. The 18-cylinder, two-row Wright R-3350 had more serious, and more deadly cooling problems front-side forward in the B-29 bomber. The R-4360 gave sterling service in aircraft such as the C-124 Globemaster for many years after the B-36 flew its last flight. Pratt and Whitney built a masterpiece in the Wasp Major engine, but of course it could not compete with turbine engines.
I don’t know anything about these but after they get started do they need fuel. This my be a dumb question because it’s an engine but does the compressed air turn the propeller so it doesn’t need fuel?
Well us brits being the stubborn buggers we are chose not to use radial engines in our air craft we went with the good old v12 even the Lancaster bomber used v12s (4 of them) the exception was the hawker typhoon powered by a Napier sabre (an h24 basically take two flat 12s put one on top the other and and use gearing to connect them to a single output shaft an h has two crankshafts).
Britain used many thousands of radial engines during the war. The Bristol sleeve-valve radials were quite successful on bombers, transports, and especially on the famous Beaufighter.
@@Hopeless_and_Forlorn Yep. They also used a lot of radial powered American aircraft like the P47. In fact, many British airmen that got "upgraded" to P51s wanted their P47s back.
Once the radial engine needed a reduction gear to drive a propeller, why stay with it? Why did Wankel not invent its engine back then before WWII (or the inverted one: Liquid Piston) ? With all the gears in the reduction planetary ( I like it ) gearbox and in the compressor gearbox, there is no argument to not also allow gears in the engine. Wankel used a gear, the V12 has some gears. With enough cylinders you can justify a large wheel behind the engine to drive DOHC. You replace stroke with RPM. Also use gears to avoid the asymmetry of a master conrod. There was a stationary radial engine which did this, but it looks like the video was taken down.
Simply: it’s not small. Complexly: the propellor is shaped perfectly, and spins so quickly that it pushes air behind the plane. Sir Isaac Newton tells us that every force has an equal and opposite reaction, so this pushes the plane forwards, and the wing is shaped so that the air flows over with a higher pressure on the bottom of the wing- this is called lift. When the engines make the plane fast enough, the air can flow fast enough creating a big enough difference in pressure for the aircraft to take off!
Dibya Jyoti Well the pistons together essentially draw a circle. So you need a piece that's the length of the radius of the circle which the axis attaches to in order to have the axis in the middle. Not sure if that was your question though.
I guarantee you, not everything you hear is right. The old pratt and whitney's found in the DC 3 and DC 4s have a radial engine with I believe 9 or 11 in a ring
The fuck you mean? Wankel (rotary), regular piston engines and radial engines can all work in 4 strokes. I think you meant the difference between a standard piston engine and a radial engine.
On the second and third watching of this video I think that this man may be evidence that Eric Cartman's little theory might just hold validity. If you look into his dead eyes when he is shown in the video you may find yourself questioning (I know I did) whether he has a soul or not.
The "two unaccounted for" were because they were so complicated that they were naturally very finicky, to the point that on virtually every mission, the B36 came back with at least one non-functioning engine. If you'd like to see a B36 on display, make a trip out to Tucson, AZ and visit the Pima Air and Space Museum. (No, I'm not associated with them. I just love aircraft.)
I'm lucky enough to live somewhat close to the museum and those planes are fucking huge
I have gotten the awesome opportunity to fly on the b-29 fifi and I have got to say the sound of a radial engine is truly the best in the world
:20 4 Stroke Cycle: My dad taught the cycle as a teenager in a way I have been able to remember it easily with all the innuendo he could muster he told me the 4 strokes were Suck, Squeeze, Bang, Blow. Now every time I hear the 4 strokes mentioned it think back on that lesson.
Thats how my wife does it too!
That’s how Kent State teaches its aeronautical students as well 😂
It's a simple way to remember when applied nightly S-S-B-B in a college environment & relate 4 stroke theory .
"Six Derping and four Herping."
XD
On that Oshkosh flight line, don't forget about the WW-II fighters and trainers that also use radials! All the Grumman fighters (F4F, F6F, F7F, F8F), the Corsair, the PT-17, BT-13, AT-6, T-28, etc. On the German side, the FW-190. And more!
I'm not watching this video to see how 4 strokes work, I'm watching to see how such a strange engine type dealt with oil containment, engine balance, and uneven wear in the era before boxers!
Inverted engines, of which many thousands were made prior to and during WWII, had oil control issues to overcome for all cylinders, not just the lower cylinders as on radial engines. Radial engines, mostly in the form of rotary engines with the engine spinning around a fixed crankshaft, were common and extremely successful during WWI, so they are hardly "weird." All piston engines have the potential for balance problems with rotating and reciprocating parts, but the radial configuration is no worse than any other. And the myth of unequal piston wear due to orientation relative to gravity is just that. The moving parts of internal combustion engines are subjected to acceleration forces of such magnitude that the force of gravity is not even a rounding error in design.
i wonder where the oil pan location is or how lubrication works out on radial engines! is there anybody who have a clue about that?
Radials are "dry sump" meaning they have no oil pan. They instead have an oil tank, normally mounted on the firewall. There are pubs, likely on line which explains how the system works. Combination of pressure feed and spraying/slinging oil onto various components.
There is a very small collection sump and a scavenging pump to remove excess oil back to the reservoir tank, oil is pressure fed from the reservoir tank to the engine by another pump.
Note that the cold start process for a radial always involves turning the motor slowly through 3-4 revolutions before attempting to start, this is because after sitting for some hours oil(and sometimes fuel or moisture) can settle in the downward angled cylinders seeping passed the piston rings into the combustion chamber and at the extreme cause a hydraulic lockup or more commonly it reduces chamber volume drastically increasing compression ratio and/or causing a hydraulic hammer(kind of like a garden hose with bubbles in it will splurt and pop and shake when you first turn the water on)
I wonder how they can fit 5 connecting rods to one lobe/throw on the crank, the would need to be really fine/thin in comparison to a car engine.... Am I missing something?
@@homewordbound4970 I see it has been some time and no one has answered. There is one rod in each bank called the master rod. The other articulated rods are pinned to the master rod at the circumference of the rod crank end. His video shows the motion but it is not explained. The explanation gets quite complicated after that. This system causes timing and stroke length errors that must be compensated for. Most engines have a compensated breaker cam in the magneto. The real part to understand is the cam ring. By a 4 lobe cam ring I mean four intake and four exhaust lobes. A nine cylinder can run with a 4 lobe cam at 1/8 engine speed in reverse rotation to engine rotation. It can also run with a 5 lobe cam ring at 1/10th engine speed in the same direction as engine rotation. If you want to draw it up start with a 3 cylinder. A single lobe will turn in reverse at half speed and a two lobe at quarter speed. If you take the time to understand the cam ring geometry you will also understand why there is an odd number of cylinders in a bank and the firing order is odd then even.
Ok I just randomly clicked on this video and the first thing I hear is "It's ass scratch week". I can't be the only one to hear that right?
RCmies "class crash"
You forgot to mention that radial engines will always have an odd number of cylinders.
Not always. Maybe nowadays.
I've only seen a photos of a radial engine/on tv, it looks like the barrels/cylinders are arranged inline/level, I'm wondering how they managed to fit 5 connecting rods/big end bearings to the crank?
I can only picture room for one unless the cylinders are slightly off?
I've often wondered when I see them on TV, I'm a bit mechanically minded but I can't get my head around that?
I'm watching Valkyrie and seen a radial so here I am trying to find out, I get the 4 stroke just can't picture the big end bearings arrangement for multiple pistons 🤔
@@homewordbound4970
Master & slave rods.
@@heinzhaupthaar5590
Thanks very much I'll look into this 👍
@@homewordbound4970 The most common arrangement is a master rod/articulated rod arrangement. The crankshaft throw (in each row, for a multi-row engine) rotates a connecting rod with a piston on the other end as usual. This is the master rod. This rod has extended flanges with multiple holes drilled into them in a circular pattern, one hole for each of the other cylinders. Each hole has a pin in it. Each pin is inserted through the "big end" of a straight connecting rod which is retained between the two flanges of the master rod. The other end of each "articulated" rod, as they are known, is a "little end" through which the piston pin is inserted, so each articulated rod also drives one piston in its respective cylinder. Each articulated rod is free to rotate side-to-side enough to keep pointing at its cylinder as the crankshaft throw moves the entire master rod, and its captive pins for the articulated rods, in a circle. So, in a nine-cylinder engine, or row, you have one piston being moved directly by the master rod, and eight more pistons connected to the periphery of the master rod by articulated rods and moving them as the master rod circles the crankcase. There are complications in this arrangement due to the fact that the articulated rods do not move on the exact circumference of the circle described by the crankshaft throw, but these geometrical characteristics can be compensated satisfactorily.
Alright I laughed a little too hard on the nicknames 😂
Great video, Thod. You are bold indeed.
Cool video but your unflinching unblinking stare into the camera frightens me a little
You must immediately retreat to your safe place, drink some hot cocoa and pet your comfort puppy.
Very intense isn't it 🤣
😶🌫️
The russians designed and developed a diesel radial that was water cool with 56 cylinders and made over of 4,000 hp. They even coupled 2 together in a package and that one makes over 10,000 hp. The engine series was so successful that they are even still in production today. They never did make it into any aircraft but they found a home in marine apllications.
If a radial engine is two-stroke (Inefficient!) it can, in theory, have an even number of cylinders, but the four-stroke Never could.
so how much power could 28 cylinders make then. id like to know.
On the specifications of the 28 cyl engine, it says 3,500HP
V14
maybe about 1600 hours power
That one deals around 4200 hp, hello from 4 years in the future btw
This video really helpful. 😊😊
Talk about how they put a radial engine in the M1 Sherman tank lol
Thank you👏🏾👏🏾👏🏾👏🏾
Are radial engines efficient than other engine types??
Not that I have any credentials or actual knowledge, but I would assume efficiency is similar to that of "regular" piston engines like what you'd find in most cars
Their main benefit is that air cooling works really well for them, so you don't need a radiator. Also, they can usually still run even if one or two cylinders get shot off. Important for a warplane.
Initially yes, very much so. That's why radials were more common in WWI. Between the wars, advancements in liquid cooling made inline engines slightly more efficient for aircraft use, thus the introduction of Merlins and Allisons and what not. But then NACA and others did some serious research on things like cowl designs that reduced drag on radial installations enough to get them back up to inline levels of efficiency. Thus giving us P47s, Corsairs, FW-190s, etc.
I just wondered how they could attach so many pistons to one crankshaft.
th-cam.com/video/cIBWNu9fIro/w-d-xo.html
@@tracersedge Thank you!
There is no reason why a two-stroke radial engine could not be built. Such an engine would fire each cylinder in the order of rotation regardless of number of cylinders, odd or even, and would always have a balanced firing interval. The R-4360 Wasp Major had cooling issues only when stuffed backwards into the wing of the B-36. The 18-cylinder, two-row Wright R-3350 had more serious, and more deadly cooling problems front-side forward in the B-29 bomber. The R-4360 gave sterling service in aircraft such as the C-124 Globemaster for many years after the B-36 flew its last flight. Pratt and Whitney built a masterpiece in the Wasp Major engine, but of course it could not compete with turbine engines.
Short and sweet...nice.
What about engine balancing? Was a radial Engine easier to balance than say inline engines?
I don’t know anything about these but after they get started do they need fuel. This my be a dumb question because it’s an engine but does the compressed air turn the propeller so it doesn’t need fuel?
@Samuel Prince oh, now I understand. Thanks a lot I’ve been trying to figure this out
so... was there any 3 row radial engine out there?
are there any engineering similarities to the Archimedes’ do nothing machine?
Awesome, sweet vid
Well us brits being the stubborn buggers we are chose not to use radial engines in our air craft we went with the good old v12 even the Lancaster bomber used v12s (4 of them) the exception was the hawker typhoon powered by a Napier sabre (an h24 basically take two flat 12s put one on top the other and and use gearing to connect them to a single output shaft an h has two crankshafts).
Britain used many thousands of radial engines during the war. The Bristol sleeve-valve radials were quite successful on bombers, transports, and especially on the famous Beaufighter.
@@Hopeless_and_Forlorn Yep. They also used a lot of radial powered American aircraft like the P47. In fact, many British airmen that got "upgraded" to P51s wanted their P47s back.
@@Hopeless_and_Forlorn I stand corrected..
Once the radial engine needed a reduction gear to drive a propeller, why stay with it? Why did Wankel not invent its engine back then before WWII (or the inverted one: Liquid Piston) ? With all the gears in the reduction planetary ( I like it ) gearbox and in the compressor gearbox, there is no argument to not also allow gears in the engine. Wankel used a gear, the V12 has some gears. With enough cylinders you can justify a large wheel behind the engine to drive DOHC. You replace stroke with RPM. Also use gears to avoid the asymmetry of a master conrod. There was a stationary radial engine which did this, but it looks like the video was taken down.
Why it is needed to close the engines in a shell like the failed one? Cause it is used in a wartime aircraft?
Cooling. The air must be forced through the cooling fins of the cylinders. This is done by the design of the pressure-cowl, the engine enclosure.
Old timey nicknames were so cheeky. I love it
I guess that didn't know about air dams
Is there a car built with a radial engine?
how to oil function in this engine plz plz plz breef
SO I Was right all along
and can you explain how radiator work i mean water cooling or air cooling radiator
This would be more of a multi bank motor not a radial. If you look up say M4 Sherman tank motors you will see the difference
Are there are any bikes having two pistons?? If there how will they work?
Radial engines require an odd number of pistons
Millions. Nearly every Harley Davidson in fact. But they are not radials
Can anyone please explain me how a small rotator helps to push the plane so fast that it can fly ?
Simply: it’s not small.
Complexly: the propellor is shaped perfectly, and spins so quickly that it pushes air behind the plane. Sir Isaac Newton tells us that every force has an equal and opposite reaction, so this pushes the plane forwards, and the wing is shaped so that the air flows over with a higher pressure on the bottom of the wing- this is called lift. When the engines make the plane fast enough, the air can flow fast enough creating a big enough difference in pressure for the aircraft to take off!
@@apexjailor9349 had no idea that not so “small” propeller is that powerful. Thanks mate.
how is balancing of rotary engines done??
Dibya Jyoti there is a piece in the axis, just like an Otto engine, i don't know It's name in english
Dibya Jyoti Well the pistons together essentially draw a circle. So you need a piece that's the length of the radius of the circle which the axis attaches to in order to have the axis in the middle. Not sure if that was your question though.
This is not a rotary engine. This is a radial engine. They are distinctly different.
I guarantee you, not everything you hear is right. The old pratt and whitney's found in the DC 3 and DC 4s have a radial engine with I believe 9 or 11 in a ring
DC3, C-47 used a PW R-1839 Twin wasp 2 rows of 7
Can someone tell me does the radial engine need a flywheel?
No. The inertia of the propeller is enough. They do need crankshaft counterweights to dampen various orders of vibration.
why radial engines have only odd number of cylinder.
@srihari vaila, this should answer your question: th-cam.com/video/qjnQKXNPsk4/w-d-xo.html
This voice is familiar to me
How hard is it to understand the difference of how a radial endgine woirks and how does a 4 stroke engine work
The fuck you mean? Wankel (rotary), regular piston engines and radial engines can all work in 4 strokes. I think you meant the difference between a standard piston engine and a radial engine.
Where's the camshaft.
Try this video, it explains how the engine works instead of just a lesson on four-stroke engine operation: th-cam.com/video/qjnQKXNPsk4/w-d-xo.html
Oversimplified
On the second and third watching of this video I think that this man may be evidence that Eric Cartman's little theory might just hold validity. If you look into his dead eyes when he is shown in the video you may find yourself questioning (I know I did) whether he has a soul or not.
He’s dead inside.
You didn’t answer the question good grief
absolutely useless.!!!
So where are the carbs? How do you throttle it? Crap video.
i learned nothing
...Then you suck at life.
Did you know a lot because why are you watching this video if you know a lot?
Thanks for the info ... But you seem, VERY smug!
The firing order is what i needed to understand per diagram.. heavy 🪖road whehicles & helicopters used radials too.