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Takeoff power / RPMs
On the RT engine only - I can not generate TAKEOFF power until such time as the engine oil temp is 120 degrees or better. I did notice this last summer, but since OAT was much warmer than here in the winter, it would not pose much of a problem because of the taxi and run up would generate the heat and all was *normal* by the time I was ready to take the runway.
Well here in the winter time, it is a little more pronounced. I have a pair of EI MVP 50's installed and, what I can tell you is that most everything appears to be normal except Fuel Pressure and RPM's. Of course none of this is obvious until such time I am ready to depart. The RPM's will come up to about 2100 for the prop and mag checks just fine. It just won't go to full power, in reviewing the EDM data on Savvy Analysis, it appears to be something that has been going on for some time, and just not as pronounced until now.
Yesterday - I made a ground test run, and set PROP, MIXTURE for take off and made sure FUEL BOOST PUMPS were on. I made it ready for takeoff in other words. I did this while the engine was not up to temp yet ( CHT's were > 200 ), during this test, I did not adjust anything but the power controls. The LT engine is performing as it should so, I have that to compare against as normal. The RT engine comes up to about 2100 RPM, Manifold pressure on both engines is the same. While monitoring the OIL TEMP, I tried 5 times to generate takeoff power. I do have Tannis heaters on this, so OIL TEMP started out at 90 degrees, and subsequent attempts to generate takeoff power were made at oil temps of 100, 105, 110, 115, 120. It wasn't until such time as I hit 119 degrees that I was able to generate full power on the RT engine. The LT engine came up to full power on the first attempt.
Any ideas would be appreciated.
- Bruce Hampton
- Posts: 2
- Joined: Tue Sep 08, 2015 1:00 am
Re: Takeoff power / RPMs
Patricia Jayne (Pat) Keefer ICS 08899
PA-39 #10 Texas
N3322G- ICS member
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- Joined: Thu May 08, 2008 1:58 pm
- Location: Fort Worth, Texas area
Re: Takeoff power / RPMs
-Zach
Zach Grant L1011jock- Technical Advisor
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- Location: Indianapolis KEYE
Re: Takeoff power / RPMs
I have considered the governors, but have not yet elected to swap them as they are time consuming, mounted in amongst the turbo's and fuel pump.
- Bruce Hampton
- Posts: 2
- Joined: Tue Sep 08, 2015 1:00 am
Re: Takeoff power / RPMs
You might also contact Lycoming, I remember vaguely a test of the oil transfer and front bearings.
Clarence
- Clarence Beintema
- ICS member
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