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Balanced Injectors from AFP

LouFly

Well Known Member
(particularly for nonbuilders) if you have an injected engine highly recommend installing balanced fuel injectors, it is one of the cheapest, non-invasive and productive upgrades I've done. Combined with new baffle seals it's made a huge difference in managing CHTs, operating economically and overall ease-of-use. Couple of hundred bucks, a couple rounds of lean tests and my spread went from .6 gph to .1 gph. I can easily find LOP by "feel" now using the BMP. Really great email support from Don.
 

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left overs?

I just ordered a set of .024" injectors from Don and will be installing them this weekend. Is there any interest in starting a thread where we can trade injectors that weren't quite right? They are not too expensive at $35 each, but I don't want to start accumulating them in the process of testing. How many tries did it take to get your balanced, and what sizes did you end up installing?

-Steve
 
leftovers

Steve,
2 passes:
- one to put Don's std injectors in (the original Lycs where not tunable)
(re-run lean test)
- second, they sent two custom restrictors for swap-out (the .0225 in the pic went into #1, #2)
...Done.

They actually sent me two sets of restrictors b/c the first got lost in the mail. Frankly for the free support and excellent service I'm going to just send the 4 restrictors back to them and they can sell them again to you, LOL.

Minor install note about clocking of the injector to avoid fuel dripping after shut-down, all in the instructions. Had a bit of dripage so I re-installed one.
 
I just ordered a set of .024" injectors from Don and will be installing them this weekend. Is there any interest in starting a thread where we can trade injectors that weren't quite right? They are not too expensive at $35 each, but I don't want to start accumulating them in the process of testing. How many tries did it take to get your balanced, and what sizes did you end up installing?

-Steve
I will be certainly interested in some trade, even if it is just for experimenting to get the right size. Please note the there is a limit as how small you can go which is driven based on your fuel pressure and Max GPH at the sea level.

I do have some sizes available for trade if anyone one is interested.
 
Steve,
Minor install note about clocking of the injector to avoid fuel dripping after shut-down, all in the instructions. Had a bit of dripage so I re-installed one.

For the nozzle replacement you will not need to remove the injector and if you have, please pay close attention that they are brass and if they break or strip, then it is going to be a major hassle.
 
For the nozzle replacement you will not need to remove the injector and if you have, please pay close attention that they are brass and if they break or strip, then it is going to be a major hassle.

My old Lyc nozzles were non-tunable, so had to be R&R'd
 
Maybe we should make this a "sticky" so it is easy to find.

Std Lycoming injectors are 0.028". I replaced one with a 0.0285" and got perfect gami spread.

0.024 and 0.0225 mentioned in the first couple of posts seems like a pretty drastic change?

The idea of having an exchange seems like a great idea.
 
Steve,
I have an IO320 in the -6A. I imagine a 360 or 540 will be different. perhaps sub-models may impact it as well.
Don recommended .022 all around for me (which made a big difference by itself) and then after testing again .0225 in the front cyl's.


Maybe we should make this a "sticky" so it is easy to find.

Std Lycoming injectors are 0.028". I replaced one with a 0.0285" and got perfect gami spread.

0.024 and 0.0225 mentioned in the first couple of posts seems like a pretty drastic change?

The idea of having an exchange seems like a great idea.
 
Don’t forget log entry

I did the GAMI test several years ago and Don had me replace my #2 injector restrictor with a 0.0285 restrictor. Unfortunately I failed to record this exercise in my logs and subsequently during an annual condition inspection, after cleaning my injectors, reinstalled the outsized restrictor on the #3 cylinder.

LOP EGTs were of course not close but I chose to ignore the issue since I wasn’t sure where the different restrictor belonged without a good log entry. Moving forward to this year’s situation where my engine is now at Popular Grove for tear down inspection, I wanted to let the folks there know about the one different restrictor for a proper rebuild.

The thought occurred to me that I might have saved the original emails between myself and Don Rivera about the change out. Fortunately that was the case and I was able to pass on the correct restrictor placement to the folks at Poplar Grove. But more importantly, I finally entered into my logs where the 0.0285 (different colored) restrictor belongs.

Don’t be stupid like I was and record your restrictor changes. Memory fails all too often.
 
switching from .028 to .024

I was initially surprised that Don recommended swapping all the injector restrictors from the Lycoming factory 0.028" to his 0.024", but he explained that the restrictors don't control the total flow of fuel, that is the fuel servo's job, and the smaller restrictors will only increase the fluid velocity and raise fuel pressure at the flow divider. That helps with atomization and should even out flow distribution between cylinders. after doing that we can make small changes to individual restrictors to fine tune. Sounds good to me. My #3 has always run a bit leaner than the others and doesn't allow me to get very far LOP before #3 EGT starts falling fast. I thought increasing that one nozzle was the best solution, but he disagrees and knows a lot more about this than I do, so I'm going to do it his way. IO-360-M1B with one Mag and one Surefly. YMMV
 
Close, but could be a little better.

I changed out the factory restrictors with the 0.024” restrictors from Airflow Performance and it helped quite a bit with the Gami spread. My fuel flow sensor bounces around a lot because of its placement, so it’s hard to use fuel flow to do the test. Instead I use the digital leaning function on my EIS4000 to measure distance from peak on each cylinder. #3 still peaks 1st, but much closer to the others than before. Today I got to about 20 degrees LOP for cylinders 1,2,and 4, with #3 about 40 degrees LOP. It needs a bit more fuel, so I will order a 0.0245” nozzle for #3. Hopefully that should do it. The engine ran much smoother LOP than it did before.
 
I was initially surprised that Don recommended swapping all the injector restrictors from the Lycoming factory 0.028" to his 0.024", but he explained that the restrictors don't control the total flow of fuel, that is the fuel servo's job, and the smaller restrictors will only increase the fluid velocity and raise fuel pressure at the flow divider. That helps with atomization and should even out flow distribution between cylinders.

Makes sense.
 
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