Pfeil's cousins for your airforce

[vanir]

Ranges for US navy planes, while "possible" were for speeds and altitudes that would be fatal in European flying. You can some rather amazing ranges from Spitfires and 109s if you fly them at 180mph at 5,000ft

An important point people forget with advertised ranges. One Wildcat ace broke down in an interview I remember watching, where he described how he was on the return leg of an escort mission, passed the last waypoint and was trimmed for lean cruise with the canopy open so he lit a cigarette. They got bounced by a flight of Zeros, who outranged them so much they could follow them all the way home and attack from high altitude over the field. In the time it took for the pilot to trim his Wildcat back to combat he said the B-17 in front of him had gone down with the crew.

In Europe you were likely to be attacked from take off to landing, there was almost no opportunity to trim the motor to burble on an oily rag while you floated around like a birdy.

 

[Siegfried]

It was pretty well established by the very late 30s that the normal tandem engine arrangement (2 engines in one long nacelle) while cutting down on drag didn't offer the same propulsive efficiency as two tractor engines. The nacelles were always too short and the rear propeller was always operating in disturbed airflow. The Do 335 does offer, by far, the greatest distance between propellers of any of the tandem aircraft so perhaps it was less of a problem.

The interesting thing is that Messerschmitt is suggesting in line tandamised DB603 engines on a variant of its Me 264 bomber known as the
Messerschmitt Me P.1075 Me Messerschmitt Me 264 Luft '46 Entry at a late stage of the war.

In addition the Dornier Do 26K, possibly the longest range production aircraft at the outset of the war used in line tandem engines.

Other aircraft:

Cessna 337 Skymaster
Rutan Model 76 Vogager (definitely longest range aircraft ever)
Adam A500 (modern commuter)
Dornier Wal
Dornier Do X
Dornier Do 18 Seaplane, the German PPY Catalina.
Dornier Do 26K Seaplane, Possibly the longest ranged seaplane ever built.
Dornier Do 335 Pfeil (arrow), Perhaps one of the fastest piston engined aircraft ever built.
Dornier Seawings Seastar, modern Seaplane of composites.

Savoia-Marchetti S.55
LeO H-242

And the Fokker D.XXIII: .Fokker D.XXIII - fighter

********

Several record breakers there.

So I tend to think that the wisdom of the supposed inefficiency of the push-pull setup is misinterpreted and that the advantages can outweigh the disadvantages.

I think the rule is more like this:
One big propeller is better than two small ones but that two in line tandems are just as good if not slightly better than equally distributed engines.

Consider the possibility of powering the He 177:
Option A: two gear coupled engines in a common nacelle on each wing. This means weight close to the wing root and has aeroelastic and structural advantages.
The amount of air in the disturbed airflow of the wing is minimized since the amount of wing area has gone up linearly with propeller diameter while the prop
area has gone up with the square.

Option B: 4 equally distributed engines: structural and aeroeleastic disadvantages, more whetted area of the nacelle more of the wing in disturbed airflow of wing.

Option C: Engines in line tandem: has structural advantages, less drag than either one big engine or gear coupled engines. Props are in disturbed airflow as per Option B. First Prop supposedly also interferes with second prop.

The Ta 152C, with a single DB603LA managed 466mph. The Do 335 with the same engine the DB603L was expected to move at 495mph. A version with the even more powerful DB603N would have broken the 500mph mark.

The XP-72 superbolt, if it ever got its turbocompunded engine supposedly faster.