Cooling engine for oil dilution?

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firebird313
Airman Basic
Posts: 7
Joined: 27 Jan 2020, 12:38

Cooling engine for oil dilution?

Post by firebird313 »

I just bought the P-51 Civ and thus far clocked 30 hrs on her. I think I am starting to get the hang of flying the Mustang, but there is one thing I can't figure out. I often fly in very cold climates (it's -20C at my home airport as of the time writing this), thus starting the bird can be troublesome. The oil dilution system would be helpful in getting that Merlin started, but for the life of me I can't get the engine cool enough to use it before walking away. The manual says to idle the engine with the flaps open until the oil temperature drops below 50C to use the oil dilution system, but I cannot get the engine oil to go below 65C flaps open. It always hovers around this temperature even with the engine idling as low as I can take it without it quitting. As for shutting the engine down to cool, the temperature only drops 2-3C per 30 minutes in my observations. For now, I am using the trick where in the payload pop up you can click the oil button to fill the engine with warm oil to aid start up.
Is there anything I can do to help the engine cool down? I already searched the forums and nothing useful came up. I prefer to operate the bird realistically.

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Tug002
Senior Master Sergeant
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Joined: 25 Oct 2013, 11:40
Location: Ontario, Canada. CYSH

Re: Cooling engine for oil dilution?

Post by Tug002 »

I have the same problem. I hope that someone comes up with a solution. :idea:

Keep smiling
Tug :)

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Jacques
Senior Master Sergeant
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Joined: 26 Jun 2011, 17:54
Location: West Coast, USA

Re: Cooling engine for oil dilution?

Post by Jacques »

I put the Mustang at Laramie Wyoming where it was -7.5 C with a calm breeze of 3 kts.
I auto started and warmed the oil to 77 C.

I moved the radiator and oil cooler to full open.

At 1000 RPM I ran the engine for more than 6 minutes for zero drop in oil temperature.
At1500 RPM I ran the engine for 3 min 26 sec for 1 degree drop in oil temperature.

I then shut the engine off (which is okay in the manual to get engine temps down for diluting the oil.)
Again, oil and coolant flaps fully open.

The temperature drop was 22 degrees over 35 minutes or a little more than half a degree (.629) per minute.

All of which is to say the best way to get your oil temps down as quick as possible is to shut the engine down. :D

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Tug002
Senior Master Sergeant
Posts: 2448
Joined: 25 Oct 2013, 11:40
Location: Ontario, Canada. CYSH

Re: Cooling engine for oil dilution?

Post by Tug002 »

Thanks for the tip. :a2a:

Keep smiling
Tug :)

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