GE "Type D-23" turbocharger?

[OldGeezer]

The XP-67's Final Report mentions (twice) that General Electric Type D-23 turbos were fitted to the engines, but it also says (twice) that D-2 turbos were fitted. I've seen material on the D-2 but I haven't been able to find out anything about a D-23, other than the callouts in the Final Report. I'd like to know more about it, does anyone know where I could look?

 

[wuzak]

Should it be B-2 and B-23 turbos?

 

[OldGeezer]

Should it be B-2 and B-23 turbos?

It's definitely D-2 on the Model 2A drawings, multiple places there and in the XP-67 Case History and Final Report. I'll go back through the records though and see if D-23 is mentioned anywhere except the Final Report. A couple of the propulsion system integration drawings are out being scanned right now so I won't be able to look at those for a couple of weeks.

 

[OldGeezer]

Should it be B-2 and B-23 turbos?

I think Kim McCutcheon got me sorted out on this. It wouldn't make sense to have a D-series turbo on the XP-67's I-1430 engine, because D-series in USAAF nomenclature only applies to engines over 2000 HP, and the 1430 wasn't rated anywhere near that at the time it was designed. It would have had either a B- or more likely C-series turbo. So D-2 and D-23 were probably GE's own part numbers, having nothing to do with USAAF's type designations. I was just confusing myself by a lack of understanding, and when you posted about B-2 and B-23 yesterday, that's what started me thinking along new paths. So thanks for that!

 

[wuzak]

C series was for larger, more powerful engines, such as the R-2800. I believe in the 2000hp range.

The B series was used with the V-1710, which would be the closest to the I-1430 in performance. Two B-series turbos were used on the B-29 with the R-3350.

 

[ddwhitney]

Gentlemen,
Referring to Turbosupercharger Type Designation Sheets: The Type D was for 1401-1800 HP Engines. The D-1 was the basic unit and rated for 1500 HP engines. The D-2 was the same with the exception that a flange is provided 180 degrees from nozzle box inlet for attaching a waste gate. Used on Douglas A-20 and F-3 airplanes, possibly others.
The Type D-23 was for 1400 HP engines, Military Rating and 1700 HP at 25,000 ft; rated speed 20,000 rpm. A Cooling shroud was fitted between turbo compressor and nozzle box baffle ring.

 

[OldGeezer]

Gentlemen,
Referring to Turbosupercharger Type Designation Sheets: The Type D was for 1401-1800 HP Engines. The D-1 was the basic unit and rated for 1500 HP engines. The D-2 was the same with the exception that a flange is provided 180 degrees from nozzle box inlet for attaching a waste gate. Used on Douglas A-20 and F-3 airplanes, possibly others.
The Type D-23 was for 1400 HP engines, Military Rating and 1700 HP at 25,000 ft; rated speed 20,000 rpm. A Cooling shroud was fitted between turbo compressor and nozzle box baffle ring.

Are these Type Designation sheets somewhere that I could look at? I've been looking for info like this for a long time without finding anything, and I'd love to see the source material. Thanks for posting!

 

[ddwhitney]

Are these Type Designation sheets somewhere that I could look at? I've been looking for info like this for a long time without finding anything, and I'd love to see the source material. Thanks for posting!

I have scanned the 25 pages of GE Type Designations into a pdf. It's a little large. If you have problems contact me and I can send it direct.

 

[OldGeezer]

I have scanned the 25 pages of GE Type Designations into a pdf. It's a little large. If you have problems contact me and I can send it direct.

That's exactly what I needed - thanks so much!!!

 

[wuzak]

I have scanned the 25 pages of GE Type Designations into a pdf. It's a little large. If you have problems contact me and I can send it direct.

Thanks for the info.

So there was a D-series turbo.

What was it used in, other than the XP-67?

 

[OldGeezer]

Thanks for the info.

So there was a D-series turbo.

What was it used in, other than the XP-67?

The only other aircraft that ever flew with the same engines as XP-67 (Continental I-1430) was Lockheed's XP-49, but it used a different turbo, the General Electric B-33. I'm curious about this myself, and I wonder whether the D-23 might have been just another experimental piece of gear that it was convenient to use XP-67 as a testbed for.