Balancing fuel flow

I have 18hrs now on my IO-360 and have tried leaning things out a bit. My cht's are close as are EGT's. So far I lean the same way I did with the club Citabria...pull the mixture until it stumbles and shove it back in a bit, this puts me near peak according to the EMS. So now with all that engine info available I want to run LOP and save a little fuel when I just out cruisin'.

I started pull the mixture and watching what's going on and it appears #1 peaks well before the others and is causing my roughness.

So what's the proper power level procedure for checking injector balance. (my search didn't help)

Hi Brian..

I just went through this on my -10..
Go to Airflow Performance web site and download their sheet for balancing your injectors and follow the simple instructions.

Basically, you start 50 ROP and lean .2 GPH. You then record all the EGT's Continue leaning .2GPH until all the cylinders have peaked, recording all their EGT's. BTW, on the mixture control knob, each raised ridge is .2GPH, so you simply turn it out by one ridge and wait a bit until fuel flows and temps stabilize. Does your EMS have a "Lean" mode like the Dynon's do?

Don Rivera at Airflow will send you the appropriate injector inserts to move all the temps closer. If you remove a fuel line at the cylinder, you'll see the insert and it may take the sharp edge of a knife to lift it out. There will be a mark on the side that might take a magnifier to read the number in thousandths that the orifice is.

Best,

This will work on any brand FI.Go to an alt. that you can run WOT start out rich record EGT and fuel flow then reduce fuel flow by .2 gph record flow and EGT then continue to reduce by .2 gph and record until engine is not running smooth. If you make a chart you can see when each cyl. peaks and what the fuel flow is at that peak a good balance is all cyl. will peak within .2 gph if not you will need adjust the flow to a cyl. by changing an enjector or a line restrictor. If you have an AP it is very easy just set a heading and record.

N184JG said:

.... If you have an AP it is very easy just set a heading and record.

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So step one, hook up my A/P

Pierre, I couldn't find the document to download at the Airflow site, but I sent them an email for guidance. Also I have a Dynon180 and have run the lean function a few times...but I don't know really what I'm supposed to be doing. where's my hammer?

The 50mph winds from yesterday appear to have died down this morning, so hopefully I can get out and burn some dinosaur juice

I have the Dynon and have used the lean function. You turn the lean function on. Go to the ems or there is a page in the flight mode also, and hit the button. than I like to go to the split screen with flight mode and ems and go rich on the fuel, generally 50rop area, and start pulling back or go lean, when you hit peak things start to happen, the first cylender starts hitting the two digit, than the next on down the line, stop when you hit numbers close to 50, for lean of peak you want the lowest number to be at 50, that means you might have one or more with a higher number. Record this data, it will have the cylenders that peaked first on down the line, and on the bottom it will tell you the spread. I would just take a camera along and take a quick pic. But I'm sure you can go into the dynon and pull the info.

hydroguy2 said:

....... I have a Dynon180 and have run the lean function a few times...but I don't know really what I'm supposed to be doing. where's my hammer? ........

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I should clarify, I know how the dynon "lean" works. and have run 100ROP and LOP, but for purpose of the testing I don't know what is the optimum testing points, such as MAP, RPM, What do I avoid, ...etc?

Nozzle Tuning

Here is the data sheet from our files:


"The basis of nozzle tuning is to get each of the cylinder EGT?s to peak at the same fuel flow. Your aircraft must be equipped with EGT information on each cylinder and fuel flow information. A digital flow meter is preferred. Adjusting nozzle size to get all the EGT?s to read the same number is not correct and can in fact damage the engine.

To gather correct data for nozzle tuning, set a cruise power setting. Typically 24? MAP and 2400 RPM. Set the mixture to be 0.5 GPH richer than peak on any cylinder. At this setting record all the EGT?s for each cylinder. Lean the mixture 0.2 GPH and record all the EGT?s again. Lean the mixture an additional 0.2 GPH; record all the EGT?s again. Continue leaning the mixture 0.2 GPH and record the EGT?s until all the cylinders have peaked.

An alternative method although not as accurate is to lean each cylinder to peak and record the fuel flow at that point. You will get the same data, but since the EGT reacts slower than the leaning process you may go past the peak and not know it. This is especially true if an engine monitoring lean find function is used. We get more accurate data taking the EGT data manually. If you use an automatic data acquisition function, allow 30 seconds or so at each fuel flow setting so the EGT value can stable out.

After the data is taken, we determine which nozzles to change to get all the cylinders to peak at the same time. You will notice that the EGT number at peak may not be the same for each cylinder, THIS IS NOT IMPORTANT. The cylinders that peak first (higher fuel flow) are the lean ones; the cylinders that peak last (lower fuel flow) are the rich ones.

Getting all cylinders to peak within 0.2 GPH is ideal."


So get you a sheet of paper with as many columns as you have cylinders plus one for fuel flow, and start recording the data.

At least you get to go flying.

Don

Thanks Don, I got your email also.

Now I just wish the weather would settle down. not exactly good tuning weather today.

METAR text: KBZN 161956Z 21019G29KT 10SM CLR 08/M06 A2932 RMK AO2 PK WND 21029/1948 SLP928 T00831061

tuning injectors

Don how is matching egt at a power setting going to damage the engine?

Data recorder for lean tests

For the sake of your fellow pilots that might be in the air at the same time, bring a data recorder (qualified passenger!) to twist knobs and write numbers down while you look out the window. Might be not be obvious until you try it. And you will get better data

hydroguy2 said:

METAR text: KBZN 161956Z 21019G29KT 10SM CLR 08/M06 A2932 RMK AO2 PK WND 21029/1948 SLP928 T00831061

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Brian-you're complaining about 19 gusting to 29? You need to come to Ellensburg someday!

BTW, your plane looks fantastic. Glad my Dynon tray found such a nice home! (That is mine, right?)

for safety reasons I'll just set up for cruise, then slowly reduce the mixture 0.2gph increments and let the Dynon record everything. I can retrieve the data back at the hangar. although I do have a friend who has been begging to be a safety pilot.

Steve, I'll make it over that way one of these days. right now, I'm a crosswind wimp. especially since my skills are so rusty. We had 40-50mph winds a couple days ago. No thanks, I'm in it for the fun. Once I can make 2 landings the same I'll expand my comfort to include crosswinds and gusts.

Dynon tray worked out great. Thanks, it helped me build my panel before I spent bigger cash.

Envy

Hydroguy2

A real data recorder! Something else that I have airplane lust for!

hydroguy2 said:

I'm a crosswind wimp. especially since my skills are so rusty. We had 40-50mph winds a couple days ago. No thanks, I'm in it for the fun. Once I can make 2 landings the same I'll expand my comfort to include crosswinds and gusts.

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Yeah, I was just kidding about the wind. There are some unflyable days like that here in Ellensburg. Rarely for visibility, but often for wind. Soon as I get up and flying I'll be over at MSO and Stevensville a lot visiting my brother so I hope to get out your way too.

Get "controlled"

zav6a said:

For the sake of your fellow pilots that might be in the air at the same time, bring a data recorder (qualified passenger!) to twist knobs and write numbers down while you look out the window. Might be not be obvious until you try it. And you will get better data

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Do as I did: file a flight plan into controlled area and "they" (ATC) will look out for you!

Regards, Tonny.

Precision Airmotive "not helpfull"!

I just did my injector balance-check. Cylinders are peaking 0,6 Gal/hr apart. I sent the numbers to Precision Airmotive with the request for injector/restrictor adjustment advice.

This is what their exact answer was: I am sorry, but we do not offer different restrictors for the injectors. From your chart, it appears that your EGT splits are well within spec and your engine is operating correctly

Because I was not satisfied with the answer I called Peter Nielson at Precision. I told him that the spread is too big for LOP operation. All he had to say was that I should not run LOP! The fact that I bought a fuel injection system, instead of a carburetor, to be able to run LOP did not interest him at all!
I asked him for the nozzle size but he would not tell me!. In the end he admitted that I could try swapping the nozzles because that might make a difference, “since their nozzles are all different sizes”!!!???. Well I jsut had to put the phone down...........

Don, if you are reading this, I am sorry that my engine builder installed the wrong system, but do you have any advice?
I can send you the chart as an excel file, if you are willing to look at it.

Anybody else with advice is welcome too! Regards, Tonny.

Airflow Performance!

Call Don at Airflow Performance. No .. you didn't buy an Airflow fuel injection system, but Don will help you anyway. He is just that kind of guy. I suspect he can help you flow-balance your system by helping you swap out your injector nozzles.

Nozzle Tuning

Tonny,

Just email me the data to [email protected]. Basically we need to know where each cylinder peaks with relationship to fuel flow. Also if you have a 4 cylinder engine you want to do this at fuel flows above 7 GPH, otherwise the flow divider is trying to divide the flow. If you want to run at fuel flows at or below 7 GPH then you probably want to start off with a set of .024 restrictors. This will keep the flow divider out of the way at these low flows but will not restrict the fuel flow at high power settings.

BTW, stock Precision restrictors are .028. I don't know what the big secret is. But you have to forgive Precision. They really only know the certified world and they only make .028 and .032 (which are not interchangeable in the same nozzle body and the .032's are only used on some of the turbo installations) injector nozzles.

Don

I can attest that if you call Don with such data he **WILL** respond.

And not only that, when I stopped by with a so equipped plane and mentioned that is was NOT his FI system, he looked at with a look of like " .. and your point is?"

He was there to HELP. And help he did. I arrived with numbers using his process but he even took the time to go flying with me and show me stuff while we got precise numbers under his guidance. (GRT System recorded data as did Don).

When we landed, he did his magic, went to the nozzle bay and picked the magic one(s), installed such in a matter of minutes, and made sure it worked as advertised.

I highly recommend Don!!

Last week, I installed a set of AFP nozzles with .025 restrictors to replace the previous .028 Precision Airmotive nozzles on my RV-4. At 21"/2400RPM to the GAMI spread went from ~0.7 GPH to ~0.1 GPH. I couldn't be happier. It's a shame that, after all these years, Precision hasn't learned the value of having matched air-fuel ratios across all cylinders.

It's so much easier to visit Don...

...if you're anywhere east of the Mississippi.

He flew with me and we tuned her in only two flights.

I have come to the conclusion that "Experimental" has raised the bar for the certified crowd to catch up to!

Best,

I have come to the conclusion that "Experimental" has raised the bar for the certified crowd to catch up to!

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About time.

East of the mississippi! yeah......

pierre smith said:

...if you're anywhere east of the Mississippi.

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Piere sure, east of the Mississippi,......... about 4.500 miles east!

So no, I am not going to visit Don with my plane. But I am in touch with him and he is sending me 4 new restrictors. When I receive them, I will do the test again. Maybe I will have to change out a few restrictor after that test. I am confident that I am now talking to the right guy.

Don, again, thanks in advance for the help.

Kind regards, Tonny.

Can I suggest you look up the AVWEB articles written by JohnDeakin ...around article 64 or there abouts are 4 articles on how to run your engine.

PRINT THEM OUT

READ THEM

..............and read them every night before bed for about 3 weeks..........YES I AM SERIOUS

Then when you understand the whole combustion process and how to run your engine...........you will be

I assume these are nice looking valves! .......... only 330hrs since new

And the pistons are the cleanest I have seen on any engine after 330 hours too.

Exhaust valves
1.


2.


3.


4.


5.


6.

What about us Carburator pilots?

Assuming we have sensors for all four cylinders, are there any options for balancing carburated engines ? (appologies if this is an ignorant question).