Editing Hyper engine (section)

===FY 1940===
A total of 26 designs, with a mix of 16 engine models from six engine companies, were submitted by seven of the selected companies. These engines became known as the "Hyper Engines", a contraction of '''Hi'''gh-'''per'''formance engines. The submitted designs were graded using a "Figure of merit" (FOM) rating system, and then, using the FOM results (which ranged from 444.12 for the Allison V-1710-E8 to 817.90 for the Pratt and Whitney X-1800-A4G), they were separated into one of three groups.

* Those placed in the first group were little more than modifications to existing designs. They were not considered to be sufficiently advanced.
* Those placed in the third group proposed using an engine that was unlikely to be developed into flying condition by the time the airframe was ready to fly. They were not considered to be viable in the time frame allowed.
* The remaining ten designs were placed in the second group: those that were an advancement in aeronautical engineering, with an engine that would be ready to fly, when needed.

Only three of these ten designs were approved, and contracts were made for a limited prototype run of three aircraft for each.<ref name="Balzer15">Balzer p 15</ref>

The three aircraft/engine combinations that were selected:<ref name="Balzer24">Balzer p.24</ref>
# Vultee Aircraft's Model 70 Alternate 2, (FOM score: 817.9), which became the [[Vultee XP-54]], powered by the [[Pratt & Whitney X-1800|Pratt & Whitney X-1800-A4G]] engine
# Curtiss-Wright St Louis Model P248C, (FOM score: 770.6), which became the [[Curtiss-Wright XP-55 Ascender]], powered by the [[Continental IV-1430|Continental IV-1430-3]] engine
# Northrop's Model N2-B (FOM score: 725.8), which became the [[Northrop XP-56 Black Bullet]], powered by the [[Pratt & Whitney X-1800|Pratt & Whitney X-1800-A3G]] engine

{|class="wikitable"  width="90%" 
|+The high-performance engines of FY 1940<ref name="Balzer24"/>
|-valign=top
! Engine model
! Configuration
! Displacement
! Horsepower
! Specific<br>horsepower
! Weight
! Power to<br>weight ratio
|-
| [[Continental IV-1430|Continental IV-1430-3]]
| inverted V-12
| 1,430&nbsp;in³
| 1,600&nbsp;hp at 3,200&nbsp;rpm
| 1.12&nbsp;hp/in³
| 1,615&nbsp;lb
| 0.99&nbsp;hp/lb
|-
| [[Pratt & Whitney X-1800|Pratt & Whitney X-1800-A3G]]
| 24 cylinder H-block
| 2,600&nbsp;in³
| 2,200&nbsp;hp
| .85&nbsp;hp/in³
| 3,250&nbsp;lb
| 0.68&nbsp;hp/lb
|-
| [[Pratt & Whitney X-1800|Pratt & Whitney X-1800-A4G]]
| 24-cylinder H-block
| 2,600&nbsp;in³
| 2,200&nbsp;hp
| .85&nbsp;hp/in³
| 3,250&nbsp;lb
| 0.68&nbsp;hp/lb
|}