LOP - AMAZING - try it if you can and haven't yet

[jetdriven]

I should have clarified a bit, but only ment to say that the red box isn't definitive but definitely do notice as you get closer to the red box how in order to get a few knots more the temps get hot quick.  I also agree with you Byron that there isn't any measurable gains in efficiency by running more than 20degrees lop and I'd bet that any gains are a result of lower airspeed.

 

if your running more than 20 LOP how about slow up the prop and then run 20 LOP.  20LOP at a lower rpm takes less fuel than 50LOP at a higher.  In fact I've noticed that Peak at a lower rpm and LOP at higher, given the fuel is the same is pretty comparable.  

 

Agreed. I only run leaner than 25 LOP to reduce fuel flow below 10.0 GPH (75% power) or to get CHT below 380.  I find myself always flying it as fast as it will go.   If I need to stretch range or get the absolute minimum trip fuel, lower RPM, then, less MP and nearer to peak seems to do the job.   Note your trip cost will go up slightly, as you incur more tach time, but if you can skip a fuel stop, thats 30-40$ and an hour saved as well.

[RocketAviator]

I always figured that 200K at 12K was a really special thing.  I think your Bravo is every bit as fast as a rocket!  So just for bragging rights - that's the 200 at not required O2 level.

 

Make a low pass over Dresden next week - I will be in some academic building there working in 1.5 weeks.  I will listen for the TSIO540 sounds.

What you talking about every bit as fast as a rocket......

[aviatoreb]

What you talking about every bit as fast as a rocket......

 

I know - I know...blasphemy....but does your rocket do better than 200TAS at 12k?  Here is the official rocket POH table:

 

78 12,000 208 240 33.0 2,400 25.0 76 12,000 205 235 32.0 2,400 22.0 65 12,000 195 200 30.0 2,200 18.0 55 12,000 186 170 26.0 2,200 15.0

 

Yes, 208TAS at 12k is on the table....at 78% and 25gph, but who cruises at that?!  Not me.  205 at 22gph at 12k is more reasonable.... and that is not a lot faster than what Awful seems to be reporting for 21.8gph  194TAS at 9500 for his Bravo.  That's a lot closer than I had realized.  It does seem to me - not knowing anything factual - that his M20M is faster than average.

 

I do admit that my rocket is 5kts or so slower than book - I blame my VGs and my TKS which is an early install.

 

Of course we rocket owners like to brag the 228TAS book speed at 76% 22gph at 24k. :-)  Or perhaps more responsibly 208TAS at 15gph 55% at 24k.  I have a very nice mask with built in mic..... Here is a mask picture - see me smiling see with the extreme speed?

[rockydoc]

Does LOP apply ONLY to turbo charged engines?

[KSMooniac]

Does LOP apply ONLY to turbo charged engines?

 

Nope!

[Hector]

Does LOP apply ONLY to turbo charged engines?

No. Applies just as well to normally aspirated engines. Your chances of achieving LOP operations is much more likely with fuel injected engines with tuned injectors. Sent from my iPad using Tapatalk HD

[rockydoc]

So, if I'm understanding this LOP procedure, I should lean to peak and then further lean to 50 over peak using EGT.  I'll certainly give it a try, but it seems that in the past when I have "over leaned" that the engine starts to stumble and i always assumed, would become fuel starved and quit.  Help me understand please.  BTW, I have a M20B.

[DS1980]

rockydoc

Seems that you are new to LOP procedures so just a few cautions

1.) You can really hurt your engine if you don't know what you are doing. The #1 rule to engine management is: You can run ROP if you run rich enough, and you can run LOP if you run lean enough.

2.) Ensure you are developing 60% HP or less. At these settings, your engine simply isn't producing enough power to hurt itself with any mixture setting.

3.) It is more difficult in your carb engine to run LOP, but it can be done. The reason why your engine runs rough is due to uneven fuel distribution as you get close to peak EGT, or even on the lean side of peak. The goal is to atomize the fuel at the carb to help each cylinder get the same amount of fuel. There are a few ways to achieve this. They are:

-Application of carb heat

-Throttle settings (Cocking the throttle plate to introduce turbulence in the carb) and

-RPM settings.

 

The key is in finding the correct sequence that works for your engine.

 

Start out straight and level at 60% power or below. It's best to do this at altitudes that won't allow 60% power at WOT so you can see if turning off your enrichment valve (economizer) is all you need to do. Just pull the throttle until it registers on the MP gauge and start from there. Then it's a matter of leaning to roughness, fiddling with carb heat, RPM and throttle, leaning, fiddling, leaning, fiddling. You may find a setting that allows you to go LOP right away. Or it may take awhile. Bring a safety pilot with you because your head should inside the cockpit paying close attention to every little setting you change. Also, bring a notebook to document what works and what doesn't. Every engine is different, even engines on the same year and make, so make sure you know what works for your engine.

 

A final reminder to keep an eye on CHT. CHT is a direct indication of Internal Cylinder Pressure (ICP), which in excessive amount is what hurts engines. Run at 60% power of below, and keep CHTs in reason and you simply can't hurt anything experimenting with LOP.

 

Let us know of any questions that pop up.

[carusoam]

DP

-a-

[rockydoc]

rockydoc

Seems that you are new to LOP procedures so just a few cautions

1.) You can really hurt your engine if you don't know what you are doing. The #1 rule to engine management is: You can run ROP if you run rich enough, and you can run LOP if you run lean enough.

2.) Ensure you are developing 60% HP or less. At these settings, your engine simply isn't producing enough power to hurt itself with any mixture setting.

3.) It is more difficult in your carb engine to run LOP, but it can be done. The reason why your engine runs rough is due to uneven fuel distribution as you get close to peak EGT, or even on the lean side of peak. The goal is to atomize the fuel at the carb to help each cylinder get the same amount of fuel. There are a few ways to achieve this. They are:

-Application of carb heat

-Throttle settings (Cocking the throttle plate to introduce turbulence in the carb) and

-RPM settings.

 

The key is in finding the correct sequence that works for your engine.

 

Start out straight and level at 60% power or below. It's best to do this at altitudes that won't allow 60% power at WOT so you can see if turning off your enrichment valve (economizer) is all you need to do. Just pull the throttle until it registers on the MP gauge and start from there. Then it's a matter of leaning to roughness, fiddling with carb heat, RPM and throttle, leaning, fiddling, leaning, fiddling. You may find a setting that allows you to go LOP right away. Or it may take awhile. Bring a safety pilot with you because your head should inside the cockpit paying close attention to every little setting you change. Also, bring a notebook to document what works and what doesn't. Every engine is different, even engines on the same year and make, so make sure you know what works for your engine.

 

A final reminder to keep an eye on CHT. CHT is a direct indication of Internal Cylinder Pressure (ICP), which in excessive amount is what hurts engines. Run at 60% power of below, and keep CHTs in reason and you simply can't hurt anything experimenting with LOP.

 

Let us know of any questions that pop up.

Thanks for taking the time to walk me through such a detailed explanation and process.  I'll experiment with it and see if I can make it work for my bird.  

[carusoam]

Doc,

Look for the thread about LOP with regards to the carburetor. There is plenty of work done and documented recently. Most without succes in running LOP with a carb.

What do you have in mind? How long of a flight?

Best regards,

-a-

[DS1980]

Thanks for taking the time to walk me through such a detailed explanation and process.  I'll experiment with it and see if I can make it work for my bird.  

Of course. LOP is how we should have been running engines from the beginning. If you're able to run LOP, along with a healthy blend of flying and Camguard, you'll sail through TBO.

[aaronk25]

Of course. LOP is how we should have been running engines from the beginning. If you're able to run LOP, along with a healthy blend of flying and Camguard, you'll sail through TBO.

Amen!!! Right on!

[Bob - S50]

Here's another link for info on many subjects including LOP:

 

http://www.savvymx.com

 

Scroll down and on the right side you'll see a button for webinar details.  Click on it and you'll go to a page with lots of free webinars you can watch including: LOP, oil, mags, alternators, tires, and on and on.  In one of the webinars he says the most efficient operation is generally about 20 or 30 degrees LOP.

 

They also have this website:

 

http://www.savvyanalysis.com

 

You can sign up for free and upload your engine monitor data to view it graphically.  If you perform a LOP leaning, and your monitor has fuel flow, you can also use it to calculate your GAMI spread.

 

FWIW, my wife and I just flew back from SQL to S50 and I was getting 155 KTAS at 8500', on about 8.7 to 9.3 GPH.  I was running from 10 to 30F LOP.  All my CHT's were below 380.  When I used the Savvy website to analyze my leaning, I found our stock injectors had a GAMI of 0.1 GPH.  I'll do it a couple more times just to verify that though.

 

Best of luck,

 

Bob

[jkgyr52]

I cannot get my 262 to run smooth LOP.  Does anyone have any solution?  I've been told by several mechanics that this engine just wont run smooth LOP.

 

My TSIO360 MB (3)B engine has a very narrow GAMI range (< 0.3 gal), the guys did not recommend GAMI injectors because they didn't think they could improve on my fuel flow.  At any rate my engine runs rough at anything below LOP.  It runs fine just slightly ROP.  We cannot find any leaks in the induction system.

 

Thanks,  Jeff

[Cruiser]

Jeff, 

 

The roughness in the engine is due to uneven power between cylinders. Normally this happens because LOP the fuel flow become critical to the amount of power produced. Thus, the "gami spread" is important to know if all the cylinders have the same amount of fuel at the same setting. (making the engine run smooth)  It seems your engine at .3 gph spread (that is the range in fuel flow from the first cylinder to peak to the last cylinder to peak) should run smoothly LOP. 

 

There are other reasons for rough running engine. Spark plugs, ignition harness, mags, induction leaks etc. You should investigate these for potential problems. As for the TSIO360 I have no personal experience but there does seem to be some issues with the turbo charger circuit causing changes in the setting so that it will not stay stable in LOP operations but this is different than "running rough"

[aaronk25]

Jeff,

The roughness in the engine is due to uneven power between cylinders. Normally this happens because LOP the fuel flow become critical to the amount of power produced. Thus, the "gami spread" is important to know if all the cylinders have the same amount of fuel at the same setting. (making the engine run smooth) It seems your engine at .3 gph spread (that is the range in fuel flow from the first cylinder to peak to the last cylinder to peak) should run smoothly LOP.

There are other reasons for rough running engine. Spark plugs, ignition harness, mags, induction leaks etc. You should investigate these for potential problems. As for the TSIO360 I have no personal experience but there does seem to be some issues with the turbo charger circuit causing changes in the setting so that it will not stay stable in LOP operations but this is different than "running rough"

Second that......worn or improperly gapped spark plugs incorrect gap can cause big issue when lop.

My dentist was at fl170 and his acclaim starting missing bad the culprit was improperly gapped and champion plugs that didn't meet the ohm test. New tempest fine wire plugs and good to go!!!!