| Maker | Lycoming O-145- C3 | Lycoming GO-145- C1 | Lycoming GO-145- C2 | Lycoming GO-145- C3 | Lycoming R-530- D1 | Lycoming R-530- D2 | Lycoming R-680- B4C |
| Arrangement | Horizontal | Horizontal | Horizontal | Horizontal | Radial | Radial | Radial |
| Cooling | Air | Air | Air | Air | Air | Air | Air |
| No of Cyls | 4 | 4 | 4 | 4 | 7 | 7 | 9 |
| Bore/Stroke | 3.625" x 3.5" | 3.625" x 3.5" | 3.625" x 3.5" | 3.625" x 3.5" | 4.625" x 4.5" | 4.625" x 4.5" | 4.625" x 4.50" |
| Displacement | 144 cu ins | 144 cu ins | 144 cu ins | 144 cu ins | 529 cu ins | 529 cu ins | 680 cu ins |
| Comp Ratio | 6.50:1 | 6.50:1 | 6.50:1 | 6.50:1 | 6.50:1 | 5.50:1 | 5.50:1 |
| bmep Cruise | 108 | 106 | 106 | 106 | 124 | 116 | 101 |
| Blower ratio | N/A | N/A | N/A | N/A | 1.0:1 | 1.0:1 | 1.0:1 |
| Cyl Material | Cast Semi-Steel | Cast Semi-Steel | Cast Semi-Steel | Cast Semi-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 | 75 | 75 | 75 | 75 | 210 | 200 | 225 |
| @ RPM | 3100 | 3200 | 3200 | 3200 | 2300 | 2300 | 2100 |
| @ Altitude | Sea Level | Sea Level | Sea level | Sea Level | Sea Level | Sea Level | Sea Level |
| HP Take-Off | 75 | 75 | 75 | 75 | 220 | 210 | 225 |
| @ RPM | 3100 | 3200 | 3200 | 3200 | 2300 | 2300 | 2100 |
| HP Cruise | 55 | 56 | 56 | 56 | 165 | 155 | 165 |
| @ RPM | 2800 | 2900 | 2900 | 2900 | 2000 | 2000 | 1900 |
| Fuel Octane | 73 | 73 | 73 | 73 | 80 | 73 | 73 |
| Prop Drive | Direct | Geared | Geared | Geared | Direct | Direct | Direct |
| Dry Weight | 167lbs | 181lbs | 191lbs | 193lbs | 430lbs | 430lbs | 492lbs |
| lb/Cruise HP | 3.04 | 3.24 | 3.41 | 3.45 | 2.61 | 2.77 | 2.98 |
| Carb(s) | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg |
| Ignition | Scintilla Mag(2) | Scintilla Mag(1) | Scintilla Mag(2) | Scintilla Mag(2) | Scintilla Dual Mag | Scintilla Dual Mag | Scintilla Dual Mag |
| Electric Starter | Eclipse | N/A | N/A | Eclipse | Eclipse | Eclipse | Eclipse |
| Length | 24.625" | 28.312" | 29.312" | 29.312" | 34.266" | 34.266" | 37.047" |
| Height/O.D. | 22.125" | 20.125" | 20.125" | 22.125" | NA | NA | NA |
| Width | 29.562" | 29.562" | 29.562" | 29.562" | 43.50" | 43.50" | 43.50" |
| Ht above bed | 9.469" | 9.547" | 9.547" | 9.547" | NA | NA | NA |
| Mount Dia | 10.25" | 10.25" | 10.25" | 10.25" | 19.25" | 19.25" | 19.25" |
Let me know if any of the above does not read true, or if you have other information that does not agree.
Wherever possible, I will update these pages on a regular basis as data comes in.