Warner Engine Handbook:

General Specification
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I. General Specifications

The following Warner Aircraft Corporation drawings, power curves, and specifications form a part of this specification:

Curve 24-A

Installation drawing No. 7716

Curve 23-A

Installation drawing No. 8100

Curve 38

Assembly drawing No. 7700

Assembly drawing No. 11300

II.  Type

This specification covers the design and construction of the Warner Aircraft Models SS50 and SS50A, direct drive, seven-cylinder, radial type, air-cooled engine.

III.  Detail Requirements

1. Rating.  This engine is rated at 145 h.p. at 2050 rpm at sea level, (take-off rating 145 hp at 2050 rpm), using 73 octane fuel.  When fixed propeller is used, this engine is rated at 145 h.p. at 2050 rpm, at sea level, using 73 octane fuel.  Engine Type Certificate No. 104 has been assigned to this engine by the Civil Aeronautics Authority.
2. Maximum Cruising Power Ratings.  The maximum permissible cruising power rating of this engine, when using a fixed propeller is 109 h.p. at 1865 rpm.
3. Weight.  The average dry weight of the standard engine is:
  1. SS50, 306 lbs.
  2. SS50A, 307 lbs.
4. Bore and Stroke.  This engine has a bore of 4-5/8" and a stroke of 4-1/4".
5. Compression Ratio.  This engine has a compression ratio of 5.55:1 and has a piston displacement of 499.8 cubic inches.
6. Crankshaft Rotation.  The crankshaft rotation, viewed from the anti-propeller end of the engine, is clockwise.
7. Center of Gravity Position.  The center of gravity of this engine, with accessories drives installed, is:
  1. SS50 - 4-1/2" forward of rear face of mounting bosses.
  2. SS50A - 4.63" forward of rear face of mounting bosses.
8. Mounting.  A mounting bolt circle, 17 inches in diameter, provides for the use of ten 5/16" diameter mounting bolts for mounting this engine.
9.

Overall Diameter and Length.  The overall diameter of this engine is 36-9/16".  The overall length of this engine is:

  1. SS50 - 29 inches
  2. SS50A - 29-3/4 inches
10. Magneto.  The shielded engine is equipped with Scintilla Type VMN7D dual magnetos.  The direction of rotation of the magneto drive, viewed from the anti-propeller end of the engine is counter-clockwise.  The firing order is 1,3,5,7,2,4,6.
11.

Spark Plugs.

  1. SS50 - Champion C-26 spark plugs are furnished with unshielded ignition.  Champion C-26-S spark plugs are used with shielded ignition.
  2. SS50A - Champion C-26 spark plugs are furnished with unshielded ignition.  Champion C-26-S spark plugs are used with shielded ignition.
12.

Fuel Metering.

  1. SS50 - This engine is equipped with a Stromberg NAR-5A carburetor which may be adapted for use with a fuel pump or a gravity fuel system.
  2. SS50A - This engine is equipped with a Stromberg NAR-5A or a Holley Model 419 carburetor which may be adapted for use with a fuel pump or a gravity fuel system.
13. Fuel.  The use of 73 octane fuel, conforming to Army Navy Specification No. AN-VV-F-761 is recommended for this engine.  The desired float needle valve pressure for gravity fuel system is 1-1/2 pounds per square inch, and the desired pressure for fuel pump system is 3 pounds per square inch.
14. Fuel Inlet Connection.  The carburetor is provided with a 3/8 Briggs Standard Pipe Tapped hole for installation of a fuel inlet connection.
15. Fuel Pump.  A fuel pump drive conforming to Installation Drawing No. 7716 is available as special equipment.  The direction of rotation of the fuel pump drive, is counter-clockwise.
16. Fuel Consumption.  The attached guaranteed minimum specific fuel consumption curve No. 38 shows the minimum specific fuel consumption is .525 lbs/hp/hr at cruising conditions.
17. Priming System.  A 1/8" Briggs Standard Tapped Hole is provided in the induction housing adjacent to No. 1 cylinder intake port to permit the installation of a priming line.
18. Oil.  See Table of Recommend oils.
19. Oil Consumption.  At rated power and speed the maximum oil consumption is .025 lbs/hp/hr.  At cruising power and speed the maximum oil consumption is 0.020 lbs/hp/hr.
20. Oil Inlet and Outlet Connections.  3/4" O.D. hose nipple inlet and outlet connections are provided in the oil pump for the installation of oil inlet and outlet connections.
21. Oil Pressure Gage Connection.  A 1/8 NPT tapped hole is provided in the oil pump housing for the installation of an oil pressure gage connection.
22. Oil Tank Vent Connection.  A 1/4" Briggs standard tapped hole is provided in the rear of the induction housing cover between the generator mounting pad and the right magneto for the installation of an oil tank vent connection.
23. Oil Pump.  An oil pump, consisting of one pressure pump and a scavenging pump built into one complete unit, is mounted below the starter mounting flange.
24. Alemite fittings are installed on rocker arm shafts for the lubrication of the rocker arm bearings.
25. Manifold Pressure.  A 1/8 NPT tapped hole for manifold pressure gage is provided in the carburetor mounting flange of the induction housing.
26. Radio Shielding.  Radio shielded ignition harness may be furnished with this engine as special equipment.
27. Booster Coil.  A terminal is provided on each right magneto block for the booster coil or booster magneto cable connection.
28. Starter.  A starter drive is furnished with this engine.  The direction of rotation of the starter drive, looking at drive, is clockwise.  The starter dog incorporates three jaws.
29. Tachometer.  A tachometer drive is provided.  The direction of rotation, looking into drives, is counter-clockwise.
30. Generator.  A generator drive is available as special equipment.  The direction of rotation of the generator drive, looking at drive is counter-clockwise.
31. Thermocouple.  Thermocouples may be installed as special equipment, by the aircraft manufacturer.
32. Intercylinder, Head, and Oil Sump Air Baffles.  Intercylinder, cylinder head and oil sump air baffles are furnished with this engine as special equipment.
33. Exhaust Collector.  Two studs, 1/4" x 28 thread, are provided on the exhaust flange of each cylinder head for installation of an exhaust collector.  Exhaust collector flanges and gaskets are provided for installation of the exhaust collector.
34. Carburetor Air Intake Housing.  The use of a carburetor heat control valve is recommended for this engine in order to obtain maximum performance.  Provision is made for the installation of a carburetor heat control valve in accordance with Installation drawing No. 7716.
35. Venturi Diameter.  The diameter of the Stromberg carburetor venturi is 1-7/8 inches.
36. Propeller Shaft End.  This engine provides a No. SAE #1 tapered propeller shaft end for the SS50.  The SS50A provides a No. SAE #20 splined propeller shaft end.
37.

Accessory Drives - Ratios.  The gear ratio of each accessory drive to the crankshaft is as follows:

  • Fuel Pump Mounting Pad and Drive:

Direction of Rotation:  Counter-clockwise
Speed (in multiples of crankshaft speed)  .4

  • Starter Mounting

Direction of Rotation:  Clockwise
Speed (in multiples of crankshaft speed) 1.0

  • Generator Mounting Pad and Drive

Direction of Rotation:  Counter-clockwise
Speed (in multiples of crankshaft speed) 1.5:1

  • Tachometer Drive

Direction of Rotation:  Counter-clockwise
Speed .5:1
38. Installation.  The installation of this engine shall be subject to the approval of the engine manufacturer.  The manufacturer's warranty is contingent upon approval of the engine installation.

IV.  Inspection and Test

All engine parts and assemblies used in the construction of the engine are thoroughly inspected for conformity to specifications and drawings.  Upon completion of assembly, the engine is tested for approximately nine hours before leaving the factory.  Following the first run-in (initial), the engine is disassembled and thoroughly inspected.  After re-assembly, the engine is given a final test in order to calibrate the fuel and oil consumption.

The following values, as determined by flight testing, shall not be exceeded under any condition:

Oil Pressure:  Minimum Idling - 40 pounds per square inch

Normal 50 to 90 pounds per square inch.

Maximum Permissible Oil Inlet Temperatures:  The maximum permissible oil inlet temperature is 200 degrees F.

Cylinder Temperatures:  Maximum permissible cylinder head temperature measure at rear spark plug gasket is 525 degrees F.  Maximum permissible cylinder base temperature measured at the lee side of the cylinder barrel is 300 degrees F.

Magneto Temperature:  Maximum permissible magneto temperature is 150 degrees F.

Carburetor Air Intake:  Carburetor cold air intake shall be approved by the engine manufacturer for distribution.  Provision shall be made for the use of hot air to the carburetor.  When using hot air, a temperature rise of carburetor air of 120 degrees F., above outside air or cold air is desirable.

Note:  The above limitations shall not be exceeded during ground operations.

Table II - List of Recommended Rocker Arm Lubricants

Brand Summer Grade Winter Grade
Conoco Rockerlube 9060 9060
Gulf Precision Grease B-B B-B
Kendall Aircraft 73 11
Lubri-zol 045 45
Marathon Rocker Arm Grease 512 512
Moboil-grease 3 3
Pennzoil 2 1-1/2
Phillips Rocker Arm Lubricant Yes Yes
Pure Oil Aircraft Rocker Arm Grease Yes Yes
Richlube Combat Rocker Arm Heavy Heavy
Shell Rocker Arm 15A 15A
Stanavo 2 1
Texaco Marfak 2 1

Table V - Fuel Consumption Data

Correct Fuel Consumption In Gal/Hour
In Level Flight For Super-Scarab Engine (145 H.P.)
Wide Open Throttle RPM Wide Open Throttle Fuel Consumption

Part Throttle Fuel Consumption
When Cruising At The Following RPM
1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300
2000 15.2 8.1 8.8 9.5 10.4 11.6 13.0              
2050 15.5 7.7 8.4 9.0 9.8 10.7 11.8 13.4            
2100 16.0 7.6 8.0 8.7 9.4 10.1 11.0 12.2 13.6          
2150 16.3 7.4 7.8 8.3 8.9 9.7 10.4 11.3 12.5 14.2        
2200 16.5 7.2 7.7 8.1 8.6 9.2 9.9 10.7 11.6 12.8 14.2      
2250 16.8   7.4 7.9 8.3 8.8 9.5 10.1 10.9 11.9 13.0 14.5    
2300 17.0   7.3 7.7 8.1 8.5 9.0 9.6 10.4 11.2 12.1 13.0 14.7  
2350 17.1     7.4 7.8 8.2 8.7 9.2 9.8 10.5 11.3 12.2 13.3 14.9

Example:  An engine turning 2150 RPM wide open in level flight should consume 16.3 gallons at wide open throttle and 8.9 gallons minimum when cruising at 1850 RPM.

The above are minimum consumptions.  Richer settings are entirely satisfactory.

 
     
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