Lockheed XP-58 Chain Lightning

[MIflyer]

Yes, the XB-42 used two V-1710's fed into a V-3420 gearbox. You wonder if the airplane had proceeded if they would have gone to a V-3420, which I suspect would have been lighter. On the other hand I suspect that two V-1710's were more reliable than a V-3420, and an engine out capability probably would have been essential in airline service.

 

[wuzak]

Yes, the XB-42 used two V-1710's fed into a V-3420 gearbox. You wonder if the airplane had proceeded if they would have gone to a V-3420, which I suspect would have been lighter. On the other hand I suspect that two V-1710's were more reliable than a V-3420, and an engine out capability probably would have been essential in airline service.

Yes, it had the remote gearbox used with the V-3420 on the XP-75.

 

[MIflyer]

Well, the V-3420 clearly was not a twinned V-1710 because it used a different crankcase, supercharger, and reduction drive.

 

[wuzak]

Well, the V-3420 clearly was not a twinned V-1710 because it used a different crankcase, supercharger, and reduction drive.

It depends what you mean by twinned engine.

The Daimler-Benz twinned engines were two complete engines that drove through a common gearbox. Each half could drive the propeller if there was an issue with the other.

The V-3420 was a twinned engine in that it was made from two V-1710s, but geared together so that they could not operate independently and had, as you point out, only one supercharger.

The H-2470 was the same, based on a pair of O-1230s joined together.

They could be considered twinned as they combine two engines into one.

Why I couldn't consider the Vulture a twinned engine is that it had only one crankshaft and shared not much with engines that proceeded it.