| Maker | Pratt & Whitney Wasp S2H1 | Pratt & Whitney Wasp S3H1 | Pratt & Whitney Wasp S1H1-G | Pratt & Whitney Wasp S2H1-G | Pratt & Whitney Wasp S3H1-G | Pratt & Whitney Hornet S1E | Pratt & Whitney Hornet S5E |
| Arrangement | Radial | Radial | Radial | Radial | Radial | Radial | Radial |
| Cooling | Air | Air | >Air | Air | Air | Air | Air |
| No of Cyls | 9 | 9 | 9 | 9 | 9 | 9 | 9 |
| Bore/Stroke | 5.75" x 5.75" | 5.75" x 5.75" | 5.75" x 5.75" | 5.75" x 5.75" | 5.75" x 5.75" | 6.125" x 6.375" | 6.125" x 6.375" |
| Displacement | 1344cu ins | 1344 cu ins | 1344 cu ins | 1344 cu ins | 1344 cu ins | 1690 cu ins | 1690 cu ins |
| Comp Ratio | 6.0:1 | 6.0:1 | 6.0:1 | 6.0:1 | 6.00:1 | 6.5:1 | 6.5:1 |
| bmep Cruise | 111 | 118 | 118 | 111 | 118 | 123 | 118 |
| Blower ratio | 12:1 | 10:1 | 12:1 | 12:1 | 10:1 | 12:1 | 12:1 |
| Cyl Material | Steel | Steel | Steel | Steel | Steel | Steel | Steel |
| Valves per cyl | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh |
| Valve Arr. | OHV | OHV | OHV | OHV | OHV | OHV | OHV |
| HP max - not Take-Off | 500 | 550 | 550 | 500 | 550 | 750 | 700 |
| @ RPM | 2200 | 2200 | 2200 | 2200 | 2200 | 2250 | 2050 |
| @ Altitude | 10500 | 5000ft | 8000ft | 10500ft | 5000ft | 7000ft | 6000ft |
| HP Take-Off | 600 | 600 | 600 | 600 | 600 | 875 | 700 |
| @ RPM | 2250 | 2250 | 2250 | 2250 | 2250 | 2300 | 2050 |
| HP Cruise | 375 | 400 | 400 | 375 | 400 | 525 | 500 |
| @ RPM | 2000 | 2000 | 2000 | 2000 | 2000 | 2000 | 1900 |
| Fuel Octane | 80 | 80 | 87 | 80 | 80 | 87 | 87 |
| Prop Drive | Direct | Direct | Geared | Geared | Geared | Direct | Direct |
| Dry Weight | 864lbs | 864lbs | 930lbs | 930lbs | 930lbs | 975lbs | 975lbs |
| lb/Cruise HP | 2.30 | 2.16 | 2.33 | 2.48 | 2.33 | 1.86 | 1.95 |
| Carb(s) | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg |
| Ignition | Scintilla Mag(2) | Scintilla Mag(2) | Scintilla Mag(2) | Scintilla Mag(2) | Scintilla Mag(2) | Scintilla Mag(2) | Scintilla Mag(2) |
| Electric Starter | Optional | Optional | Optional | Optional | Optional | Optional | Optional |
| Length | 42.938" | 42.938" | 47.734" | 47.734" | 47.734" | 44.234" | 44.234" |
| Height/O.D. | 51.437" | 51.437" | 51.437" | 51.437" | 51.437" | 54.437" | 54.437" |
| Width | NA | NA | NA | NA | NA | NA | NA |
| Ht above bed | NA | NA | NA | NA | NA | NA | NA |
| Mount Dia | 23.375" | 23.375" | 23.375" | 23.375" | 23.375" | 23.375" | 23.375" |