What Turbo Supercharger Model?

[airplane176]

Does anyone know the turbo supercharger model used or proposed in the following aircraft?

Douglas A-20 (the first model - no suffix letter)
Martin YB-10A
North American XB-28/A
Lockheed XC-35
Grumman XF6F-2 (R-2600 version)
Boeing XP-4
Curtiss X/P-5
Boeing XP-12G
Grumman XP-50
Grumman XP-65
Bell XP-77

Thank you in advance.

Roger

 

[Jabberwocky]

The XV-770 as installed in the XP-77 had no turbocharger. Or supercharger, for that matter. The supercharger for the engine ran afoul of development delays, and never made it into the XP-77 (I think).

There was a Bell proposal for a all-metal turbosupercharged XP-77. From memory, they wanted a C Series turbocharger, but I'd have to double check that.

 

[wuzak]

Does anyone know the turbo supercharger model used or proposed in the following aircraft?

Douglas A-20 (the first model - no suffix letter) - one A-20 was powered by a turbocharged R-2600. I would imagine it would have been a C-series turbo, considering the size and power of the engine, subsequent versions (A-20A onwards) doing without
Martin YB-10A - as an early turbocharged model it would have been GE Form-10 turbos (forerunner of the B-series), like on the XFM-1
North American XB-28/A - the XB-28 used an R-2800/GE C series turbo combination. The XB-28A used the same engine as the XA-26A/B/C so was without turbo
Lockheed XC-35 - I would guess it would be a Form-10 turbo, going by the size and power of the engine
Grumman XF6F-2 (R-2600 version) - not built? The second XF6F-2 had an R-2800 and a Turbo Engineering "Birman" turbocharger. Not successful
Boeing XP-4 - possibly the same as the Y1P-25. A very early turbo, most likely a GE unit
Curtiss X/P-5 - possibly the same as the Y1P-25. A very early turbo, most likely a GE unit
Boeing XP-12G - possibly the same as the Y1P-25. A very early turbo, most likely a GE unit
Grumman XP-50 - GE B-series
Grumman XP-65 - none. It was to be the army version of the F7F which had 2 stage R-2800s, but no turbo
Bell XP-77 - None - see Japperwocky's reply

Thank you in advance.

Roger

The early turbos were somewhat unreliable. The XP-50 prototype was lost when one of the turbos exploded in flight and the pilot had to bail out. That was in 1941.

 

[wuzak]

There was a Bell proposal for a all-metal turbosupercharged XP-77. From memory, they wanted a C Series turbocharger, but I'd have to double check that.

The C-series would be far too big for the Ranger. A B-series would also, probably, be too big.

 

[Shortround6]

The XV-770 as installed in the XP-77 had no turbocharger. Or supercharger, for that matter. The supercharger for the engine ran afoul of development delays, and never made it into the XP-77 (I think).

There was a Bell proposal for a all-metal turbosupercharged XP-77. From memory, they wanted a C Series turbocharger, but I'd have to double check that.

The XP-77 engine had a single stage-single speed supercharger as flown (all the V-770 Rangers did that made over 400hp). You are correct in that the intended model V-770 with it's associated supercharger never made it into the XP-77. The intended supercharger was 2 speed and sort of a stage and half. One or more axial rotors in-front of the centrifugal stage. The post war "D" series V-770 never made the power at altitude that the was claimed/proposed for the 1942/43 project.

I doubt that Bell really wanted a "C" series turbo for the XP-77 as the turbo was unsuited for engines below 1500-1800 hp.

 

[Shortround6]

The early turbos were somewhat unreliable. The XP-50 prototype was lost when one of the turbos exploded in flight and the pilot had to bail out. That was in 1941.

The early turbos were ALL GE products. Some were a bit on the crude side (like needed greasing through Zerk fittings every few hours) but then that is what development is for

Birman doesn't really get into it until 1940-42.

Please remember that in the late 20s and early 30s not only was GE supplying what few turbos there were but was supplying ALL US engine manufacturers with regular (mechanical) supercharger designs, parts and even complete superchargers. One reason for the US being a bit slow in catching the British in supercharger design. P&W and Wright not starting to design their own superchargers until the second 1/2 of the 30s.

 

[airplane176]

Jabberwocky,

Of course you are correct. I was thinking of the XV-770-9 with mechanical supercharger. I did not know about the other proposal. Thank you.

Wuzak,

Thank you for the list. You are also of course correct about the XB-28A. I am trying to find out what the XF6F-2 would have been delivered with had it been completed in that form. Likewise, the XP-65 initial proposal. Perhaps neither of these was far along enough to specify an exact model.

Shortround,

Yes, nearly all U.S. turbos were supplied by GE. I have a few odd ones from Wright (Curtiss SC-1), and Birmann (experimentally in the XF4U-3 and R-2800 XF6F-2).

Thank you all for your information. I am trying to pin down exact models for my website U.S. and German Military Aircraft Database, 100+ Years Worth. Perhaps someone has access to the XC-35 at the NASM?

Roger