Fokker DVII with 250 HP BMW

[leo]

Shortly after Anton Fokker left Germany for Holland he was able to install a 250 HP BMW in a Fokker DVII airframe. How did it compare to the 185HP BMW? Was there a significant gain in performance or was the additional weight of this engine detrimental to the ship?

[Craig]

Do you know that it did, in fact, weigh more?

[leo]

No, I honestly don't know that it weighed more. Increases in HP often were accompanied by increase in weight.

[Dan_San_Abbott]

Leo:
I have trying to find the article on the Fok. D.VII with the BMWIV, so far I have not found it, I remember it said the D.VIIwould max out at 142 mph.
The BMWIIIa weighed in at 643.5 lbs. it produced 180 hp at 1410 rpm and 254 hp at 1600 rpm.
The BMWIV weighed 671 lbs, it produced 250 hp @ 1450 rpm and 310 hp. at 1600rpm.
The superority of the BMW IIIa is evident when compared to the Mercedes D.IIIaüv which produced a maximum of 204 hp @ 1600rpm.
Blue skies,
Dan-San

[leo]

Dan-San:

Thank you for your reply. Give tne performance figures for the DVII with the 250HP BMW, how would it have performed against the 300HP Dragonfly equipped British Fighters. That is, if they had been able to get that engine to perform.

[Dan_San_Abbott]

Leo:
* *when the ABC Dragonfly worked and produced it's horse power, the Sopwith Dragon (snipe) would do 150 mph.
the Nieuport Nighthawk 151mph, the Siddeley S.R.2 at 6500 ft did 145 mph. *There were a couple of fighters the RAF was looking at with the 300 Hisso, they did: Martinsyde F.4, 145 @S/L, The Vickers 16H did 147 @ S/L. *The Fok. D.VII with the 250 ps BMW would still be at a disadvantage in max air speed. *i have often wondered why they did not put the 300 Hisso in the S.E.5a? It was cranking along at 137mph with 200 hp. I would not be surprized if it would not hit 150 mph at ground level with the 300 Hisso?
* * * * * * * * * *Blue skies,
* * * * * * * * * * * * Dan-San