LOP Power Formula for TCM TSIO360 Engine?

[FlyingAggie]

Today we experimented with operating my "new" Mooney 262 LOP.  My instructor was impressed with how smooth the engine ran LOP. It seemed to run smoother LOP than ROP.  The a/c is equipped with GAMI's.  At 50 degress ROP the fuel flow is about 11 gph, but at 50 degrees LOP the ff drops to about 8.5 gph.

I know for the Lyc IO360, the formula for amount of power is P(hp) = 14.9*FF(gph).

Does anyone know the power formula for the TCM TSIO360?

I am now 8 hrs into my Mooney transition training, but feel I have only scratched the surface.

[Earl]

Quote: FlyingAggie

Today we experimented with operating my "new" Mooney 262 LOP.  My instructor was impressed with how smooth the engine ran LOP. It seemed to run smoother LOP than ROP.  The a/c is equipped with GAMI's.  At 50 degress ROP the fuel flow is about 11 gph, but at 50 degrees LOP the ff drops to about 8.5 gph.

I know for the Lyc IO360, the formula for amount of power is P(hp) = 14.9*FF(gph).

Does anyone know the power formula for the TCM TSIO360?

I am now 8 hrs into my Mooney transition training, but feel I have only scratched the surface.

[FlyingAggie]

The a/c is equipped with a JPI 700.   We have been running about 100 df ROP, but were just comparing 50 ROP to 50 LOP fuel flows. I have been using a 65% power setting (24", 2500 RPM).

Yes, taking the APS course is high on my list.

Quote: ehscott

I have the number at home with my notes to the APS seminar and will send it along.  Just out of curiosity, how did you find LOP?  Do you have a JPI 700 or comparable?  On another note, running 50 dF ROP is pretty close to the worst power setting in terms of CHT and internal cylinder pressure (ICP) unless you are running at 65% or lower power setting. 

I have a 1986 252 with OEM injectors and have not been able to get it to run smoothly LOP so when I am flying at greater than 65% power I run 100 dF ROP.  Not sure if you have taken or considered taking the APS seminar on engine management but I highly recommend it.  I learned a lot about engine management.

[KSMooniac]

Alan, it should be 13.7 * FF for your engine, so your 8.5 GPH setting = 55%.

For your next experiment, you might want to set up in "hi cruise" at a relatively high MP and 2400 or 2500 RPM, and then smoothly and quickly pull back to 11.5 GPH (75%) and see how that works.  Once it is stabilized there, you might enrichen slowly until you hit peak, and see how far LOP you were at 11.5 GPH and go back to 11.5 GPH.  You don't want to linger at peak for very long...just enough to find a reference point.  Hopefully you'll be in the 40-50 dF LOP range at 11.5 GPH.  Record your CHTs at that setting and compare them to whatever the book says for 75% ROP at 100 dF ROP. 

[KSMooniac]

Oh, I should add that I have zero experience with the TSIO-360 engine, so I'm not sure if your MP will stay constant when you go LOP using the "big mixture pull" (BMP) method I described above.  You might have to add more throttle, but all you need to remember is fuel flow is the driving factor when LOP and you can use whatever MP and RPM combo you wish.  Different RPMs might be smoother, so experiment around.  There will be slight efficiency differences too for a given prop and RPM, but not important enough to sweat just yet. 

[FlyingAggie]

Scott,

That is the equation that Cleon had me use this morning in figurung power settings.  We played with different power settings at 10K'.  We seemed to have trouble operating LOP at 65% which would be about 10GPH, but at that setting the TiT would exceed 1600 dF.  We also had trouble with using the JPI's "Lean Find" mode.  Either we are misunderstanding what is supposed to happen or the JPI 701 is not working right.  Do you know of any tutorials on using the JPI Lean Find mode to setup LOP.

Today was a lots of fun. I flew twice and racked up another 3.5 hrs of Mooney time.  The landings really started coming together.  This afternoon we took the 262 up to 13,500' and did an emergency decent down to 10,000.  It was gear down, speed brakes out, prop forward and bank at 45 deg and hold 132 knots.  We fell like a rock: 3500'in 30 seconds!  That 7000'/min!!!!  It made my ears hurt, but good to know if I am at 24,000 feet and my oxygen fails, I can get down before passing out.

We also worked on go arounds and emergency landings.  Cleon pulled the power to idle at TPA and had me land to with no power.   We also experimented with how you can extend the glide by pulling the prop all the way back.  You can definitely feel the acceleration or deceleration.

So I now have 12.4 hrs in my Mooney!

Quote: KSMooniac

Alan, it should be 13.7 * FF for your engine, so your 8.5 GPH setting = 55%.

For your next experiment, you might want to set up in "hi cruise" at a relatively high MP and 2400 or 2500 RPM, and then smoothly and quickly pull back to 11.5 GPH (75%) and see how that works.  Once it is stabilized there, you might enrichen slowly until you hit peak, and see how far LOP you were at 11.5 GPH and go back to 11.5 GPH.  You don't want to linger at peak for very long...just enough to find a reference point.  Hopefully you'll be in the 40-50 dF LOP range at 11.5 GPH.  Record your CHTs at that setting and compare them to whatever the book says for 75% ROP at 100 dF ROP. 

[Parker_Woodruff]

Glad you got the TSIO-360s to run LOP.  GAMIs probably helped you here.  In my Piper Seneca II time with the same engines I couldn't get LOP on either, but they didn't have GAMIs.

[KSMooniac]

Alan, when you hit the LF button on the JPI, before you start leaning, hold both buttons down together for a second or two and then it will enter the LOP mode.  It is helpful!  Once you reach peak, the graph will invert and it will show you the EGT for the last to peak, which is the proper reference when LOP.  (When leaning for ROP settings, you use the first to peak.)  Lemme know how that works for y'all!

[Cruiser]

Quote: FlyingAggie