Warm-up time for DB 601A engine?

[Eric S]

I'm researching a documentary film about the Japanese Seiran airplane which was equipped with a variant of the German DB 601A engine. We understand it had a way of pre-warming by pumping warm oil through canals in the engine to cut down on warm up time. (The plane was carried in a hangar on a sub, so minimizing surface time for the sub was crucial.)
Does anyone know more about this?
How long would it take otherwise to warm up a similar engine without the warm-oil technique?
How long did it take to warm up American carrier-based aircraft engines?
What happens if the pilot tries to throttle up before proper warm up?

Thanks,
Eric S.

[jimh]

American WWII type engines use 40 degrees C as a minimum temp before any power application. 1820, 1830, 2600, 2800, Merlin...

jim harley

[FLYBOYJ]

Originally Posted by Eric S

How long would it take otherwise to warm up a similar engine without the warm-oil technique?
How long did it take to warm up American carrier-based aircraft engines?
What happens if the pilot tries to throttle up before proper warm up?

Thanks,
Eric S.

Warm up times on aircraft recip engines vary. Usually the manufacturer would give provisions based on cylinder head temps and oil temps. For the most part a recip would be considered "warmed up" if the oil temp is in the green, the green arc on the oil temp gage. If the outside air temp is cold, it could take a while as opposed to starting up a recip on a warm day. This could be anywhere from 10 - 20 minutes depending on OAT and the type of engine we're talking about.

For the most part there will be no issues if a pilot throttles up prior to reaching normal operating temps, but this continued practice can cause damage to bearings and other components as the oil hasn't reached a temperature to ensure proper flow and lubrication throughout the engine. In extreme cases when the oil is real cold, there will be no lubrication to portions of the engine and ultimately you will see the same internal failures as if the engine was ran without oil.

I could go into more detail but I hope this explains it.

[FLYBOYJ]

From a P-51 checlist...

At 2000 RPM, check the following:
Suction: 3.75" to 4.25" Hg.
Hydraulic pressure: 800-1100 psi.
Ammeter: not exceeding 50 amps.

Check instruments for limitations:
Oil Pressure: 70-80 psi desired, 90 psi max.
Oil Temperature: 70°C-80°C desired, 90°C max.
Coolant Temperature: 100°C-110°C desired, 121°C max.

http://www.aerofiles.com/checklist-p51.html