| Maker | Continental W670-K | Continental A-40-4 | Franklin 4AC150 | Franklin 4AC171 | Jacobs L-5 | Jacobs L-5M | Jacobs L-5MB |
| Arrangement | Radial | Horizontal | Horizontal | Horizontal | Radial | Radial | Radial |
| Cooling | Air | Air | Air | Air | Air | Air | Air |
| No of Cyls | 7 | 4 | 4 | 4 | 7 | 7 | 7 |
| Bore/Stroke | 5.125" x 4.625" | 3.125" X 3.75" | 3.625" x 3.625" | 3.875" x 3.625" | 5.50" x 5.00" | 5.50" x 5.00" | 5.5" x 5.00" |
| Displacement | 668 cu ins | 115 cu ins | 150 cu ins | 171 cu ins | 831 cu ins | 831 cu ins | 831 cu ins |
| Comp Ratio | 5.4:1 | 5.14:1 | 6.6:1 | 6.25:1 | 6.00:1 | 6.00:1 | 6.00:1 |
| bmep Cruise | 123 | 90 | 94 | 97 | 105 | 105 | 105 |
| Blower ratio | N/A | N/A | N/A | N/A | N/A | N/A | 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 | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh | 1 Inl 1 Exh |
| Valve Arr. | OHV | Side Valve | OHV | OHV | OHV | OHV | OHV |
| HP max - not Take-Off | 225 | 42 | 50 | 60 | 285 | 285 | 285 |
| @ RPM | 2175 | 2700 | 2300 | 2350 | 2000 | 2000 | 2000 |
| @ Altitude | Sea Level | Sea Level | Sea Level | Sea Level | Sea Level | Sea Level | Sea Level |
| HP Take-Off | 225 | 40 | NA | NA | 300 | 300 | 300 |
| @ RPM | 2175 | 2575 | NA | NA | 2125 | 2125 | 2125 |
| HP Cruise | NA | 30 | 37.5 | 45 | 210 | 210 | 210 |
| @ RPM | NA | 2300 | 2100 | 2150 | 1900 | 1900 | 1900 |
| Fuel Octane | 65 | 65 | 70 | 70 | 73 | 73 | 73 |
| Prop Drive | Direct | Direct | Direct | Direct | Direct | Direct | Direct |
| Dry Weight | 460 lbs | 145 lbs | 161 lbs | 204 lbs | 510 lbs | 504 lbs | 525 lbs |
| lb/Cruise HP | 2.04 | 4.83 | 4.30 | 3.58 | 2.43 | 2.40 | 2.50 |
| Carb(s) | 1x Stromberg | NA | 1x Marvel or Stromberg | 1x Stromberg | 1x Stromberg | 1x Stromberg | 1x Marvel |
| Ignition | Scintilla Mag | Scintilla Mag | Scintilla or Eisemann mag | Scintilla Mag | Scintilla Mag | Scintilla Mag | Scintilla Batt/Mag |
| Electric Starter | Eclipse | N/A | N/A | Auto-lite | Eclipse | Eclipse | Eclipse |
| Length | 34.187" | 14.25" | 27.969" | 27.969" | 19.00" | 19.00" | 19.00" |
| Height | 42.50" | 21.312" | 18.375" | 18.375" | 43.50" | 43.50" | 43.50" |
| Width | NA | 25.50" | 34.375" | 34.375" | N/A" | N/A | N/A |
| Ht above bed | NA | N/A | 11.187 | 11.187" | N/A | N/A | N/A |
| Mount Dia / Bearer Spacing | 20.00" | 10.00" | 10.00" | 10.00" | 16.50" | 16.50" | 16.50" |
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.