Degrees LOP (With Poll)

[201er]

I'm curious how far you LOP you set things for cruise? How many degrees F EGT LOP and at what power setting? Do you go further LOP at higher power? Do you think the Mooney/Lycoming360 "red box" is different than the typical IO550/Bonanza settings that are discussed?

[jetdriven]

I usually set 15-25 LOP and go with what I can get speedwise.  I am pretty sure there is no operational reason, other than controlling CHT or limiting yourself to 75% power, to go leaner than 50 LOP.

 

Above 8K I run between peak EGT and 10 LOP.

[garytex]

I'm looking for 8.5 to 8.7 GPH, and smooth engine operation.  Typically winds up 30-50 df LOP, 165 to 175 mph true from 5000 to 10,000 ft. fastest at 6-8000ft on a cool day.  This is in a SWTA modded F fairly light.  

[Jeff_S]

I think I end up about 10-20 LOP most of the time, but that's not my prime criteria for setting final fuel flow. I definitely use the LOP mode on my JPI to get to LOP, and turn it off when I've got it in the neighborhood of 10-20 degrees. But then I turn the JPI back to standard mode and just watch the CHTs.  When things are working well, the #1 cylindar peaks last and I try to keep it at about 350 degrees, with the #2-#4 cylinders coming in between 320 and 340.  Mostly I just look at the "missing bar" segment and want to see the second bar missing for #1 and the first bar missing for all the others.  If that missing bar starts to go higher than 2nd segment on any cylinder than I enrich the mixture and start over again for the current conditions.

[OR75]

I do care about fuel but cruise ROP. (these don't have to be mutually exclusive)

[John Pleisse]

ROP

[tyrefoote]

1988 205 With Top Prop

Richest cyl set at peak egt and  Leanest is usually 30 f LOP egt

8.8 gph  8000 msl  Isa+20 = 158 KTAS

or

8.8  ""     5000 ""         ""        156 "

[Steve Dawson]

Running LOP for some practice IFR Procedures.  

[sleepingsquirrel]

Can I vote if I have a carburetor?  

[jetdriven]

I have a friend with an RV-8 who runs his engine LOP, a carburetor and an O-360 Lycoming.

[Riq]

I have 1500hrs on my TN carbed 360, and fly at around 50 lop when the turbo is spinning. My compressions at annual were all 79.

 

I even ran around the country for 150hrs with a bad tach reading 150 low (it sounded loud, but im getting older.

[jlunseth]

GAMI/APS's recommendation for turbo engines was 60 d LOP in the seminar I attended.  That is a very long way LOP though, the engine is likely not to let you get there.

[Hank]

I have a friend with an RV-8 who runs his engine LOP, a carburetor and an O-360 Lycoming.

 

The O-360 in my Mooney gets really rough passing through peak. I run ~70-72% on the rich side. My wife lets me know when I hit peak, often just as I'm seeing it on the EGT to the lower left of my yoke. "Lean to rough" is a pretty good match!

[aviatoreb]

I have a friend with an RV-8 who runs his engine LOP, a carburetor and an O-360 Lycoming.

 

Is that just good luck that his carb engine is balanced anyway enough to do it and not something to generally expect possible?

[M016576]

Most of my flights are between 7500-11500. Richest cylinder at Peak. Below 7500 I set 30d LOP.

[jetdriven]

Is that just good luck that his carb engine is balanced anyway enough to do it and not something to generally expect possible?

I haven't flown with him, but IIRC he sets the throttle slightly off full to give the intake charge some swirl, and leans until all cylinders are LOP.    Its a stock Mattituck O-360.

[carusoam]

IO-550(g), w/ Sensenich 3-blade

T/O: full rich

Climb: approx 200f ROP (blue box) on the EGT.

Cruise, usually above 10k', 20 - 50f LOP, 165kts, 12gph.

unless ultimate speed is important that day 175kts ROP 16 gph.

Ultimate speed is not usually worth the extra gas flow...

Best regards,

-a-

[aaronk25]

If you tell me you run ROP to get a extra 5-7kts in speed ill buy it you can tell me you are willing to pay the extra price in fuel and shortened engine life to do it, that's fine with me but if you tell me your doing it for the benefit of the engine it's time to erase everything you know about engine mgt. and watch mike Busch's webinar.

You are dead wrong if you think your helping your engine by running richer...flat dead wrong.

[jetdriven]

I dont think its a given you get shorter engine life ROP, but you do spend a tremendous amout more money due to the loss of efficiency by doing to.

[aaronk25]

Look at cht rop in a j in the summer, there higher than 380 most likely 390 + maybe even 400! All that extra fuel does that doesn't get burned is provide slight power increase but for the most part gets wasted in extra heat which is already plentiful in air cooled motors.

Unless I ran less than 60% power I don't think it's possible to keep the cht low enough unless ran more than 100rop, which carbons up the valve stems and loads the oil full of combustion by-products.

Bottom end might last the same if you keep the oil clean, but my engine monitor has shown me ROP cooks the heads.

[jetdriven]

Yes, in the hot summer above 65% power, our J will not stay below 400F when ROP, I have tried that.  However, the heat is the enemy, not automatically ROP.

[aaronk25]

I see what you mean Byron. Sorry for not being specific. It just seems like you and me cover this topic so many times it gets almost painful to keep going through the background my bad.