| Maker | Gnome-Rhone Mistral Major 18L | Gnome-Rhone Mistral Major 14M | Hispano-Suiza 12Y21 | Hispano-Suiza 12Xirs-1 | Hispano-Suiza 14AA-04 | Hispano-Suiza 14AB-02 | Renault 4PG1 |
| Arrangement | Radial | Radial | Radial | V 60 | V 60 | Radial | Radial |
| Cooling | Air | Air | Liquid | Liquid | Air | Air | Air |
| No of Cyls | 18 | 14 | 12 | 12 | 14 | 14 | 4 |
| Bore/Stroke | 5.75" x 7.09" | 4.80" x 4.57" | 5.91" x 6.69" | 5.12" x 6.69" | 6.13" x 6.69" | 5.32" x 5.12" | 4.72" x 5.51" |
| Displacement | 3308.64 cu ins | 1157.78 cu ins | 2196 cu ins | 1647 cu ins | 2759.6 cu ins | 1589 cu ins | 386.1 cu ins |
| Comp Ratio | 6.10:1 | 6.50:1 | 7.0:1 | 5.80:1 | 6.20:1 | 6.20:1 | 5.30:1 |
| bmep Cruise | 145 | 148 | 133 | 158 | 151 | 141 | 103 |
| Blower ratio | 8.94 | 5.65 | 8.24 | 10.0 | 10.0 | 10.0 | N/A |
| Cyl Material | Steel | Steel | Steel | Steel | Steel | Steel | Steel |
| Valves per cyl | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh | 2 Inl 2 Exh | 2 Inl 2 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh |
| Valve Arr. | OHV | OHV | OHV | OHV | OHC | OHC | OHV |
| HP max - not Take-Off | 1300 | 650 | 910 | 720 | 1120 | 680 | 105 |
| @ RPM | 2150 | 3000 | Not Given | 2200 | 2125 | 2400 | 1800 |
| @ Altitude | 12000 ft | 12000 ft | 11811 | Not Given | 9350 ft | 11483 ft | Sea Level |
| HP Take-Off | 1400 | 700 | 880 | 740 | 1070 | 650 | 100 |
| @ RPM | 2150 | 3000 | 2400 | 2600 | 2125 | 2400 | Not Given |
| HP Cruise | NA | NA | NA | NA | NA | NA | 85 |
| @ RPM | NA | NA | NA | NA | NA | NA | 1700 |
| Fuel Octane | 87 | 87 | 85 | 85 | 85 | 85 | 72 |
| Prop Drive | Geared | Geared | Geared | Geared | Geared | Direct | Direct |
| Dry Weight | 1622.6 lbs | 881.8 lbs | 1036.2 lbs | 848.8 lbs | 1311.7 lbs | 1025.1 lbs | 319.5 lbs |
| lb/Cruise HP | 1.25 | 1.36 | 1.14 | 1.18 | 1.17 | 1.51 | 3.76 |
| Carb(s) | 1 X Bronzania | 1 X Bronzania | 1 X Own | 1 X Own | 1 X Own | 1 X Own | 1 X Zenith |
| Ignition | Bosch Mag(2) | Bosch Mag(2) | Bosch Mag(2) | Bosch Mag(2) | Bosch Mag(2) | Bosch Mag(2) | Sev Mag(2) |
| Starting Method | Own, El. Motor | Own, El. Motor | Viet, Cartridge | Viet, Cartridge | Viet, Cartridge | Viet, Cartridge | Viet, Cartridge |
| Length | NA | NA | 67.72" | 61.81" | 64.96" | 55.51" | 50.00" |
| Height/O.D. | 55.12" | 37.40" | 36.61" | 35.92" | 49.60" | 39.76" | 27.56" |
| Width | NA | NA | 29.92" | 28.34" | NA | NA | 17.32" |
| Bed centres | NA | NA | NA | NA | NA | NA | 21.26" |
| Mount Dia | NA | NA | NA | NA | NA | NA | NA |
Let me know if any of the above does not read true, or if you have information that does not agree. Wherever possible, I will update these pages on a regular basis as data comes in.