DB 605 vs Merlin

[Tempest109]

I personally prefer DB 605 over Merlin in single engine application. With DB 605, you can put arnament (MG and Cannon in the spinner) in the nose, provided the plane design had enough space. That is enough for air supremacy one.
Putting DB 605 in Bf 110 was a waste of time.

While Merlin, in my opinion is better for double engine one.

How about others opinion?

 

[Thumpalumpacus]

I'm not a fan of nose-mounted armament, slows down the cyclic and usually limits ammo stowage.

 

[pbehn]

I personally prefer DB 605 over Merlin in single engine application. With DB 605, you can put arnament (MG and Cannon in the spinner) in the nose, provided the plane design had enough space. That is enough for air supremacy one.
Putting DB 605 in Bf 110 was a waste of time.

While Merlin, in my opinion is better for double engine one.

How about others opinion?

Before the war started the British decided they needed 8 0.303 MGs unrestricted by being synchronised to take down a bomber with a 2 second burst of fire.

 

[MiTasol]

The cannon is not synchronized as it fires thru the centre of the prop - not thru the blades.

 

[wuzak]

I would say that being able to put a cannon through the prop does not mean that the engine is superior.

And it also will depend on what version of 605 and, more importantly, which version of the Merlin?

 

[pbehn]

The cannon is not synchronized as it fires thru the centre of the prop - not thru the blades.

I agree, it is obviously true, but you cant arrange 8 MGs around the engine of a single engined aircraft

 

[Tempest109]

I'm not a fan of nose-mounted armament, slows down the cyclic and usually limits ammo stowage.

Actually in this case is fighter vs fighter one. If you want bomber interception, cannon in wings is better idea or you go with 190 route combining sync and unsynced one

 

[Tempest109]

The cannon is not synchronized as it fires thru the centre of the prop - not thru the blades.

My bad, I forget whats the correct term

 

[Tempest109]

I'm not a fan of nose-mounted armament, slows down the cyclic and usually limits ammo stowage.

Understandable. In many case, Soviet prefered that style. I think to keep the agility.

 

[Thumpalumpacus]

Understandable. In many case, Soviet prefered that style. I think to keep the agility.

Right, it helps both accuracy and perhaps roll-rate. All the same, I'm not a fan.

 

[pbehn]

I'm not a fan of nose-mounted armament, slows down the cyclic and usually limits ammo stowage.

It can cause CoG issues too, but lets not get seduced by the dark side of the forum.

 

[pbehn]

Actually in this case is fighter vs fighter one. If you want bomber interception, cannon in wings is better idea or you go with 190 route combining sync and unsynced one

In 1940 the RAF didnt have the luxury of sending out planes to take on fighters and others to take on bombers, you took on what arrived.

 

[Shortround6]

Well, some of this stuff didn't spring into being overnight.

The German DB 605 started back with the DB 600. The DB 605 inherited the cannon through the propshaft.

The Russian M-100 series of engines go back to the French HS engines in about 1933-34 (Russians took out a license). and they inherited the cannon through the propshaft

The cannon of 1933-36 were not the cannon of 1942.
The engines of 1933-36 were not the engines of 1941-42.

If you have 850-1000hp engines you can only put so many cannon and machineguns in a plane.
If you have 1200-1600hp engines you can put a lot more cannons and machine guns in a plane.


British (and French radials) were putting two 20mm cannon (badly) in a single engine fighter in 1940. They got a lot better in 1941.
One 20mm through the prop in a DB 605 was not enough in 1942.
At least not for the average pilots. But now the choice starts to become 1 cannon or 3 cannon and the engine won't give the desired performance with 3 cannon.

This is more than a bit simplified but what the Germans were trying to do with the DB 605 in 1942 has very little to do with what they were trying to in 1933-38 when they started down the through the propshaft gun. It has a lot to do with trying to use the same airframe from 1935-38 with a bigger engine.
The British were also trying to use the airframe but the bigger airframe offered more space to fit more guns once the engines gave more power.

 

[MiTasol]

I agree, it is obviously true, but you cant arrange 8 MGs around the engine of a single engined aircraft

That is for real. Two seemed the practical limit and then you have all the hassles of sychronizers and significantly reduced firing rate and the CG movement that comes when you fire off all the ammo.
Ammo on or below the CG as in most wing mounted gun installations eliminates all those issues.

 

[Tempest109]

That is for real. Two seemed the practical limit and then you have all the hassles of sychronizers and significantly reduced firing rate and the CG movement that comes when you fire off all the ammo.
Ammo on or below the CG as in most wing mounted gun installations eliminates all those issues.

How about the wing root one?

 

[ThomasP]

Wing root mounted guns have the problem of reduced ROF due to the need for synchronization, combined with the problem of reduced roll rate due to the mass being off of centerline (although to a significantly lesser extent than guns mounted further out in the wing).

Also, depending on what you are designing the airframe for (say intercepter vs LR escort), there is the problem of fuel tank placement. If you need to use space in the wing for fuel stowage, then wing root mounted guns would require that the fuel tanks be further out in the wing, causing problems with roll rate. This outer wing fuel tank problem could be reduced somewhat by using the fuel in these tanks first, so that by the time you reached the combat area the tanks were empty. But if you can not count on fighting at a range from base that would use up this fuel, the roll problem remains. This is one of the reasons that wing fuel tanks were usually placed close to the fuselage in fighters, another reason being that the wing is usually thicker there, which makes it easier and more efficient (in terms of both tank weight and volume) to install the fuel load there.

 

[MiTasol]

And most landing gears retract into the wing root as that is where the wing is thickest which allows for good sized wheels

 

[tomo pauk]

I personally prefer DB 605 over Merlin in single engine application. With DB 605, you can put arnament (MG and Cannon in the spinner) in the nose, provided the plane design had enough space. That is enough for air supremacy one.
Putting DB 605 in Bf 110 was a waste of time.

While Merlin, in my opinion is better for double engine one.

How about others opinion?

A fellow member( with much more knowledge than what I have) listed the engine qualities' priorities as such:
1 - power
3 - size (or weight) penalty
5 - weight (or size) penalty

2, 4 and 6 = reliability (we asume that engines can be actually had, ie. no point in discussing the engines that were unavailable)

We talk mid-late 1942 on (when DB 605 is in service).
A 2-stage supercharged Merlin makes better power, the better the higher we go. It is much more reliable in any version. Size and weight are in balpark, the intercooler adds to the installation size of the Merlin, but that can be circumvented. Between mid/late 1942 and the end of the war, ability of the DB 605 to have the cannon firing through the prop is a moot point, since the fighters now have enough of power to carry cannons in the wing and still perform.