Tried LOP....

[74657]

We tried LOP yesterday.  I'm still not comfortable enough using the LF mode of my EDM-830 and didnt use it.  This is what we got....

10000 ft.

172 Kts TAS

Fuel flows went down from 15 to 11.8

Does everything look OK in the photo?

[danb35]

Your #6 CHT (and probably #5 as well) is a bit high. Leaning a bit more will drop it to below 380, which is where you want it to be. 

[74657]

OK Thanks.  The CHT probes are the "spark plug piggyback" style that read higher (about 40F. according to Mike Busch's articles).

[danb35]

All of them?  That's a little unusual; usually you'd only have those on the cylinder with the factory CHT probe. In any case, yes, that would account for a higher reading. 

Were you shooting for 55% power for testing purposes?  A nice thing about that low of a power output is that you really can't harm the engine with the mixture setting. Was the engine running smoothly?

[Jeff_S]

The LOP mode on the JPI series is so easy to use, I would encourage you to get comfortable with it quickly. It seems like your engine runs LOP quite nicely, but you were probably closer to Peak with those readings. I find the LOP mode on the JPI even easier than the ROP mode...once invoked, you just keep leaning until you see the last cylinder "icicle" graph come down and then just lean until you like the setting depending on your altitude.  Then you're done! Compare this to ROP mode where you have to lean until you see the first cylinder hit (and go past) Peak, then press-hold the button to see where Peak was, then go back and enrichen until you hit your desired target on the ROP side for that cylinder. Too many steps!

[74657]

The scalar for the HP is off..... 

20.3" was full MP @ 10K.

All 6 cylinders have the spark plug probes.  The CHT bungs have tanis heater elements in them.  The engine was running as smooth as a top!

Thanks for the help.  I need to get used to the icicles.  It freaked me out the only time I tried using it!

[WardHolbrook]

Just a question...

Have you considered taking these guys' LOP training course, either live or online?

http://www.advancedpilot.com/

http://www.advancedpilot.com/'>Sure, either option costs some $$$, but nothing like knowledge and understanding to help out with the "it freaked me out" stuff. 

[74657]

I understand the physics behind LOP operations.  My understanding of the EDM-830 is what is lacking.  I have always flown ROP with target CHT's @ 380 and EGT's under 1400.  I have a trip to Denver this week and want to go non-stop.  Saving an extra 3 gallons and hour will give me extra margin.  Especially on the westbound leg.....

 

I will look into the link you posted.  Thanks!

[bnicolette]

74657...............could use a name in your signature block.

Anyhow, here is a short video I did of the JPI830 in LOP mode.  Press the LF button if it's in ROP mode, then hold both buttons until you see LOP.  Start leaning and don't stop until you see the word "richest".  Now the value that you are LOP will be in the lower left hand corner and the FF in the lower right hand corner.  Continue leaning until you are at the value below LOP you want to be.  Now press the "step" button to return the JPI to regular operation.  Do it a couple times and it will be second nature.

Hope this helps.

 

[74657]

Thanks Brett!

What are guys running LOP?  40-50 degrees?

 

[danb35]

Quote: 74657

What are guys running LOP?  40-50 degrees?

[timpercarpio]

Could some explain exactly what the"red box" is?

Thanks, Tim

[danb35]

The "red box" is an area of mixture settings best avoided for optimum engine life.  Its size varies with power output, and below about 60% it disappears entirely.  See http://www.avweb.com/news/pelican/183094-1.html for a chart depicting the red box, though there are others.  If you google "red box" site:avweb.com you'll find quite a bit of information on the subject.

[DaV8or]

The problem with the "Red Box" is, it's a fuzzy estimate. They're not hard numbers and the boxes that are out there on the web were developed on big bore engines. It's just sort of a rough guideline and no serious testing has been done to my knowledge on the Lycoming IO-360 other than by the factory.

[jetdriven]

According to Lycoming you can run at peak at 75% power and below.  APS teaches 65%, but they are aiming to turbo airplanes and big Continentals. FWIW I have been treating the "red box"  as beginning at 75% and have seen no ill effects.  FWIW 10.0 GPH LOP will limit you to 75% power.

[KSMooniac]

To roughly quote Walter Atkinson from APS:  "the physics are everywhere the same!"  The concepts apply to just about any 4-stroke engine out there, from lawnmowers to radial-engined warbirds to IO-550-powered Mooneys and Bonanzas, and yes, our IO-360 powered Mooneys.  They've run IO-360s on the test stand in Ada, as well as many other engines.

[DaV8or]

Quote: KSMooniac

They've run IO-360s on the test stand in Ada, as well as many other engines.

[jetdriven]

It also applies to the installation.  I know an S35 Bonanza has way worse cooling than an M20J.  I will tell you our coolest CHTs in cruise are below 4000 feet or so, full throttle, and leaned to 10.0 GPH.  This is around 50-100 LOP and the hottest cylinder is 330.

A little more about that, there are MANY BT pilots running their TN Bonanzas at 85% or even 90% power, at 90 deg F LOP.  Even Walter Atkinson.  FWIW they arent having engine problems as long as their engine doesnt run over 400 CHT and everything else is in line. That said, I dont think you could hurt an IO-360 Lycoming doing it either, but i lack a real-time graphic engine analyser to actually to go out and log the data.  It  would only apply to low altitude opertions anyways, and an M20J at 6k feet is faster than sea level anyway

[DaV8or]

I'm not sure how I'd run 90% power LOP. I think at WOT, if I twist the mixture to get 12 gph, I don't think I'd be LOP anymore. I don't know. Never tried it.

[jlunseth]

Well, it is interesting to say the least to run a turbo LOP.  I have had quite a bit of work done on my TSIO-360-LB and am at the point where fuel distribution and overall engine operation is even enough to allow LOP.  I flew a four hour trip this past weekend at 6,000 and found the secret was to maintain a high MP and use the mixture control to control %HP.  I was running at about 37.5 MP and 11.1 GPH, which works out to 73% HP and that is exactly what the algorithm in the EDM 930 was displaying.  In the stock 231 engine 37.5 would be ok, but in my intercooled LB anything over 36" is invariably an overboosted condition.  It would produce about 110% HP at mixture full on takeoff, if I allowed the MP to go that high.  In this instance, in LOP ops, the CHT's were around 340, TIT was about 1575.  That is just a little bit behind peak in my engine, about 20 LOP.  I am not ready to go to 80+ percent HP I don't think.  Would probably not be LOP anymore, but somewhere around peak or 25ROP. 

[jetdriven]

Disregard, the Missile is naturally asiprated.

[FBCK]

jlunseth, what kind of speed where you producing at that MP and at what allitude.  I have a similair configuration to yours but usually keep the MP to 32 inches, I was somewhat concerned about getting closer to 36 inches in cruise. At 31 inches and a FF of 11.5gph at 15000 I was at 175 knots the other day in my 231.

[Txbyker]

Please guys don't laught at me too much...do I have to have GAMI to run LOP?  

My oil runs 200-205, 50 degrees ROP.  LOP oil temps look great.

[Parker_Woodruff]

Quote: txbyker

Please guys don't laught at me too much...do I have to have GAMI to run LOP?  

My oil runs 200-205, 50 degrees ROP.  LOP oil temps look great.

[jlunseth]

Quote: FBCK

jlunseth, what kind of speed where you producing at that MP and at what allitude.  I have a similair configuration to yours but usually keep the MP to 32 inches, I was somewhat concerned about getting closer to 36 inches in cruise. At 31 inches and a FF of 11.5gph at 15000 I was at 175 knots the other day in my 231.