- Holder
- Franklin Engine Company
- Revision
- 0
- Status
- Current
- Product
- Engine
- Models
- 1
The release keeps the latest revision of each data sheet. Model names are as the data sheet lists them.
On this page
Models · 1
| Model | Also known as | Note |
|---|---|---|
| O-425-9 | Formerly Aircooled Motors (Military) |
Airworthiness directives · 0
ADs whose products are models on this data sheet, matched by model and maker.
No ADs matched this data sheet’s models
Registered aircraft
Registry models that point at this data sheet, with their registered aircraft.
STCs approved under this data sheet · 1
What the data sheet says
From the PDF’s text layer, line by line: tables lose their columns. The PDF is the record.
FRANLIN ENGINE COMPANY
MODELS: Aircooled Motors Franklin Military O-425-9
T.C. NUMBER: 5E-13
Model O-425-9
Type - 6HOA Geared 0.623: 1
Rating:
Maximum continuous,
hp, rpm, at S.L. press.
alt. 240-3200-S.L.
Take-off, hp, rpm,
at full throttle 245-3300
Fuel (minimum grade
aviation gasoline) 80/87
Bore and stroke, in. 4.75 x 4.00
Displacement, cu. in. 425
Compression ratio 7.4: 1
Weight (dry), lbs. 413
C.G. location
From front face of
thrust nut, in. 18.4
Forward of rear face
of crankcase, in. 10.5
Below C.L. of
crankshaft, in. 30.0
Propeller shaft,
SAE No. 20
Ignition, dual Stromberg PS-78D carburetor
Timing, deg. BTC Scintilla S6LN-22 magnetos
Spark plugs 28
Oil sump capacity,
quarts 13
NOTE 1. Maximum permissible cylinder head, barrel, and oil inlet temperatures, 475 degrees
F.,
325 degrees F. and 210 degrees F., respectively. The cylinder head temperature is measured
with a well type thermocouple.
NOTE 2. Carburetor fuel pressure limits, 11 to 13 psi.
NOTE 3. The following accessory provisions are provided:
Accessory Drive Directions* Drive Speed* Maximum Torque (in. lbs.)
Cont. Static
Starter C 1.000: 1 - - - - 6000
Generator C 2.368: 1 500 2200
Vacuum and hydraulic pump C 1.125: 1 100 800
Governor C 0.833: 1 125 2300
Fuel pump CC 0.750: 1 25 450
*”C” - Clockwise, “CC” - Counter clockwise
**Speed - Times crankshaft rpm