What does a BF-109E that spent 80 years at bottom of a frozen lake look like?

[Rexedgar]

It had an upside down, fuel injected V-12 made by Diamler Benz. The crankshaft was drilled and rifled to fire a 20MM cannon shell through the center of it. Wild, huh?

Rereading your post, Grandpappy, care to diagram how the 20mm cannon would fire thru the crankshaft?

Given the time we spent/spend around the internal combustion engine, you would think we would have known better from the top…….





6th note from the bottom left: tunnel for cannon

 

[Rexedgar]

It seems to be that an ICE crankshaft doesn't have an actual centerline that could be used as a gun barrel.

There is a centerline on a crankshaft. All the main bearings line up, the problem comes when you attach the connecting rods and set the works in motion..

 

[Gaius46]

I figured that the propeller was offset from the theoretical crankshaft centerline. And that it had a gear reduction to reduce RPM so the propeller tip speed wasn't too fast. I can't recall why there's a maximum tip speed.



I solved that in #8.

Props are basically rotating wings and suffer all the same trans-mach and mach issues that wings not optimzed for supersonic flight do.

 

[Antiwar]

There is a centerline on a crankshaft. All the main bearings line up, the problem comes when you attach the connecting rods and set the works in motion..

There is a theoretical centerline, and a partial physical centerline. But the connecting rod attachment to the crank throws are a problem to contend with.

And shooting bullets through a crankshaft that's rotating at thousands of RPMs? Does the barrel rifling take this into account? Would that be good for the engine? Does a crankshaft with a ~1" barrel make sense?



A picture of a Bf109 crankshaft would be cool for this thread.

 

[Antiwar]

Props are basically rotating wings and suffer all the same trans-mach and mach issues that wings not optimzed for supersonic flight do.

That's getting closer. I'm remembering turbulent airflow at the prop tips would be very inefficient and possibly destroy some props.

 

[Questerr]

Take it up with Wikipedia.

I did:

List of most-produced aircraft - Wikipedia

en.m.wikipedia.org

Notice how the Bf-109 is not at the top of the list?

 

[HennyBogan]

Let me show you!

This was the German aircraft that fought the Battle of Britain. The Kraut pilots called it an "Emil" for the BF-109E.

Solid

 

[Rexedgar]

There is a theoretical centerline, and a partial physical centerline. But the connecting rod attachment to the crank throws are a problem to contend with.

And shooting bullets through a crankshaft that's rotating at thousands of RPMs? Does the barrel rifling take this into account? Would that be good for the engine? Does a crankshaft with a ~1" barrel make sense?



A picture of a Bf109 crankshaft would be cool for this thread.


View attachment 67384312

A crankshaft is a crankshaft is a…….you get the idea.

If you slow down and read the post you are replying to you will see that we are in agreement. You stated that a crankshaft doesn’t have a centerline. I disagreed and stated the reason. We agree that bullets cannot be fired through a crankshaft in motion. And 20mm is closer to 3/4”….


A picture of a Bf109 crankshaft would be cool for this thread.

see post # 26

 

[Antiwar]

Rereading your post, Grandpappy, care to diagram how the 20mm cannon would fire thru the crankshaft?

Given the time we spent/spend around the internal combustion engine, you would think we would have known better from the top…….


View attachment 67384299


6th note from the bottom left: tunnel for cannon

Fantastic drawing! And it looks to actually be a drawing. Do you know what engine that is? Didn't @Grandpappy or someone say the Messerschmitt engines were supplied by Rolls Royce? A supercharged inverted V-12 is interesting.

 

[Rexedgar]

Fantastic drawing! And it looks to actually be a drawing. Do you know what engine that is? Didn't @Grandpappy or someone say the Messerschmitt engines were supplied by Rolls Royce? A supercharged inverted V-12 is interesting.

I you had read post # 13 you would have your answer. I don’t think Rolls-Royce was on good terms with the German aircraft industry in the war years…….

 

[Antiwar]

A crankshaft is a crankshaft is a…….you get the idea.

If you slow down and read the post you are replying to you will see that we are in agreement. You stated that a crankshaft doesn’t have a centerline. I disagreed and stated the reason. We agree that bullets cannot be fired through a crankshaft in motion. And 20mm is closer to 3/4”….


A picture of a Bf109 crankshaft would be cool for this thread.

see post # 26

I don't need to slow to see all of that because I saw all of that.

The projectile is 20 mm. I'd think that the cannon tube would need to be significantly larger in diameter.

I know, you kind of had to agree with me! Do you feel dirty?

 

[Antiwar]

I you had read post # 13 you would have your answer. I don’t think Rolls-Royce was on good terms with the German aircraft industry in the war years…….

I had already read #13. It doesn't answer my questions. Thanks.

 

[Rexedgar]

I don't need to slow to see all of that because I saw all of that.

The projectile is 20 mm. I'd think that the cannon tube would need to be significantly larger in diameter.

I know, you kind of had to agree with me! Do you feel dirty?

On the contrary, I feel “peace, love and understanding.”

 

[Antiwar]

On the contrary, I feel “peace, love and understanding.”

Get a haircut!

 

[Antiwar]

Pappy (Boyington) should put an inverted V-12 in his 37 Hudson Terraplane Utility Coupe. That'd stick it to Toyota Pious drivers!

Now this is badass:



I love artillery wheels, that green, and the brickwork:

 

[Antiwar]

A crankshaft is a crankshaft is a…….you get the idea.

If you slow down and read the post you are replying to you will see that we are in agreement. You stated that a crankshaft doesn’t have a centerline. I disagreed and stated the reason. We agree that bullets cannot be fired through a crankshaft in motion. And 20mm is closer to 3/4”….


A picture of a Bf109 crankshaft would be cool for this thread.

see post # 26

If you had read whatever post of mine that was, you might've seen that I asked if that drawing was an RR.

 

[Fledermaus]

Another view of the engine.

Crank above the cannon which fires through the hub..

 

[Gaius46]

That's getting closer. I'm remembering turbulent airflow at the prop tips would be very inefficient and possibly destroy some props.

It’s been a while so I don’t remember the details but there’s a huge increase in drag as you approach the local speed of sound. The flow over the prop or wing may reach Mach 1 while the prop tips (or wing as a whole) are still well below the speed of sound.

The issue is essentially that above some
speed air becomes compressible and the normal rules of subsonic flight - which assume air to be incompressible - no longer hold. In effect the air molecules don’t move fast enough to get out of the way of the airfoil (thats a pretty gross oversimplification but like I said it’s been a while).

 

[Evilroddy]

Regarding the cannon firing through the propeller shaft debate, the Messerschmitt BF-109E and some later models starting with those produced after the Battle of Britain, but not during it, had a 20mm cannon installed between the banks of the inverted Daimler V-12 and firing through the prop hub. It was able to do this because the prop was not directly connected to the engine crankshaft, but was rather spun by a reduction gear-box which offset the propellor upwards and put it in line with the cannon's gun barrel. Later some Messerschmitts used a 30mm cannon in the same place. The installation was not considered to be very effective as it was quite difficult to service and didn't allow the plane to carry much ammunition.

I hope that clears up any confusion my previous post may have caused.

Cheers and be well.
Evilroddy.

 

[Evilroddy]

Ah, crap. I got my bearings wrong in the post above. The engine is inverted so the gear-box shifted the propeller shaft downwards, not upwards. Apologies.

Cheers and be well.
Evilroddy.

 

[Antiwar]

Another view of the engine.

Crank above the cannon which fires through the hub..

...

 

[Antiwar]

 

[Fledermaus]

View attachment 67384528

Like I said.

Crank above the cannon which fires through the hub..

 

[Antiwar]

Like I said.

Crank above the cannon which fires through the hub..

I saw that. I didn't tag nor quote you.

 

[Fledermaus]

I saw that. I didn't tag nor quote you.

Post #46

Yes you did.