A

avi8tor50

Well Known Member
Hi all-

Trying to learn to use the Dynon EMS leaning mode function. I understand how the display indicates the order in which cylinders peak. I'm a bit unclear as to the significance of the numbers that follow the peak order and how they should be used to determine leaning status.

I guess what I need is to hear how folks use the Dynon EMS lean mode.

Thanks.

Peter K
9A Phase I
 
Hey Peter.

I lean until they all go lean of peak and then push the mixture in until I'm ROP. Lycoming recommends 100 degrees ROP for carbureted engines such as mine.

I can't remember if you are injected or not. If so, once your engine is broken in, you can climb and run LOP below 65% power, if injected.

Some who have carbs and electronic ignition do run LOP but it is not recommended.

Congrats on getting your plane flying! Give me a call when you get a chance so we can catch up.
 
Why?..Old wives tales again?

N941WR said:
Hey Peter.

I lean until they all go lean of peak and then push the mixture in until I'm ROP. Lycoming recommends 100 degrees ROP for carbureted engines such as mine.

I can't remember if you are injected or not. If so, once your engine is broken in, you can climb and run LOP below 65% power, if injected.

Some who have carbs and electronic ignition do run LOP but it is not recommended.

Congrats on getting your plane flying! Give me a call when you get a chance so we can catch up.
Click to expand...

I can see no reason why you can't run LOP as long as the engine is relatively smooth, whether your carbed or not.

The worse you will have is a mixture imbalance, but so what..If you have all your cylinders somewhere between say 20 and 100F LOP and it runs smooth then go for it.

What possible problem will it cause the engine?..In fact it should be a whole lot better than continually running ROP.

As to the LEAN mode on the Dynon..I found its really not that useful except to find your sweet spot..Once you have found it I just lean to that point everytime.

For instance I cruise typically at 24 sq at 7 to 7.5 GPM...So I take off climb to altitude, set to 24 sq than haul back on the red knob until the engine splutters and nudge it forward to my required fuel flow.

Spends almost no time futzing around trying to find th eperfect point that way, plus once this is set you can adjust the throttle to go slower and the mixture knob doesn't need to change.

Frank
 
Peter,
The numbers next to the peaking order tell how many degrees LOP or ROP the cylinder is. The number at the bottom shows the split in GPH between the 1st and last cylinder to peak. Ideally you would like to see 0.0 GPH, but mine normally is less than 0.3 GPH difference. I set my Superior IO-360 at about 45-50 LOP which yields a smooth running engine with great temps. After a while you'll set fuel flow for your specific power setting like Frank does, but I still like to be in the LEAN mode with the Dynon to see the order of cylinder peaking, and where I'm running LOP.
 
OK-so if it is (-)26 that means LOP? I get the number of the cylinder, a dash, and then a number. How do do you know if the number is ROP or LOP? If the difference in fuel consumption between the first and last cylinder is 0 does that mean you are at peak?

Peter K
 
This is the problem

with Lean mode.

The number say 1-26..Means that #1 cylinder was first to peak and it is now running 26F less than peak..Note less than means it could be running LOP or ROP..depends which way you approached peak from. If you were gradually leaning from the rich side..the -26 means it is LOP..But if you came from the lean side then it would mean it is ROP.

The real trouble with all this is you have to let the EMS find peak, which means endless fliddling and waiting for the readings to settle down...From the rich side this means hanging around in the "detonation zone" of say 50F ROP.

I'd rather not do that..Now of course if your running lower power it shouldn't detonate anyway..But I'd rather get to my ideal point quickly.

The way to use the LEan function and not hang around on the rich side is to do the big lean..I.e pull the mixture till it splutters..then enrichen until it just runs smooth...You should now be LOP.
Then hit the lean mode and start richening a little at a time...Now you find peak from the lean side..it also means you will have to lean again after you have found peak on each of the cylinders.

This got to be way too much hassle and thats why I never used it after I figured out that 8.1 GPH IS peak at 24 squared..So anything less than that is LOP on all cylinders.

set it to 7 to 7.5 and call it good..runs real cool and life is good..:)

Frank
 
I agree wholeheartedly with everything Frank said - just wanted to add what may be obvious: if you are unsure whether you are ROP or LOP, adjust the mixture slightly and see which direction the EGTs go. If you enrichen and the temperatures go down, you are ROP. If the temperatures go up, you are LOP.

erich
 
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