Here are the starting instructions for the "Twin Wasp S1C3-G" as shown in Pratt and Whitney Specific Operating instructions 72 dated September 16 1946 and revised October 25 1962 (Part No. 118450)
STARTING.
CONTROL SETTINGS
Ignition: Off
Mixture: Idle Cut-off
Propeller: High RPM (Low Pitch)
Carburettor Heat: Cold (Off)
Cowl Flaps: Full Open
Oil Cooler Shutters: Closed (or Automatic)
Throttle: 1/10 to 1/4 Open (to give 800-1000 rpm after engine starts)
The following starting procedure is recommended with direct cranking starters:
1. Before starting the engine, note the manifold pressure gage reading to use as a reference during subsequent power and magneto checks. This is field barometric pressure.
2. Fuel supply - ON
3. Auxiliary fuel pump - ON
4. Motor over the engine with the starter. If possible, watch the propeller motion. At any sign of hesitation or stoppage, disengage the starter, turn off the auxiliary fuel pump, and investigate. Do not prime until Step 6.
5. After the engine has turned freely fourteen blades for engines equipped with three-bladed propellers to ensure adequate oil supply being pumped to the reduction gears, turn ignition to BOTH. If less than one hour has elapsed since the previous shut-down, let it turn freely six blades and turn ignition to BOTH.
6. Prime while cranking - intermittently if engine is warm, continuously if cold.
7. After engine fires, slowly ease mixture control out of Idle Cut-off to Automatic Rich using prime as required until engine is securely started.
8. After engine starts, adjust throttle to 600 to 800 rpm, watching for oil pressure rise.
Etc etc….
This is also official but in these days of the Aircraft Flight Manual being the "Bible" this could probably be considered as the engine manufacturer’s guide to the aircraft manufacturer! And of course Douglas wasn’t the only aircraft manufacturer to use the R1830.
Blackburn