GAMI Fuel Injectors for IO-360

[Philz7A]

Engine: Lycoming IO-360-A1A (2010 vintage)

I have big difference (100 - 125 deg.) between my coolest and hottest (cyl. #1) EGTs when leaning to LOP. I can't really operate LOP on all cyls. with this big
of a difference (starts running a little rough). After reading a few posts here of folks trying to adjust the flows themselves with different sized jets, so I don't know if I
want to fool with this so I'm considering purchasing a set from GAMI ($850)
Update: Not now - have ordered a smaller jet from AirflowPerformance. $38.
Anyone here done this on their IO-360 and are you happy with the results?

Updated Info: I have swapped the #1 & #3 EGT probes with almost no difference in temps after and also inspected and cleaned
the #1 fuel inj. nozzle/jet also with no difference after.

 

[Mark Dickens]

Engine: Lycoming IO-360-A1A (2010 vintage)

I have big difference (150 deg.) between my coolest and hottest EGTs when leaning to LOP. I can't really operate LOP on all cyls. with this big
of a difference. After reading a few posts here of folks trying to adjust the flows themselves with different sized jets, I've decided I don't
want to fool with this so I'm considering purchasing a set from GAMI ( $850, https://gami.com/gamijectors/gamijectors.php ).
Anyone here done this on their IO-360 and are you happy with the results?

Nothing against GAMI but they are very pricey and oriented toward the certified crowd. Give Don Rivera a call at Airflow Performance. He can help you for a lot less money

 

[Philz7A]

Nothing against GAMI but they are very pricey and oriented toward the certified crowd. Give Don Rivera a call at Airflow Performance. He can help you for a lot less money

Thanks Mark! I think that's a better option. I cleaned the "offending" #1 cyl. nozzle/jet (no difference) yesterday so it’s really not a difficult thing to do. The #1 cylinder was actually running quite a bit richer than the other three, even though it had about 100° higher EGT reading at times. That’s what had me confused.

 

[recapen]

The actual temps are not the concern. Placement of the EGT sensors is never exact and will cause a difference in reported temps. As others have said Don at AFP is the go to...
The trick to LOP is fuel flow being close to each other when they peak.
I have an AFP system in my 6A's IO360B1F6 and run LOP with a spread of .01gph.
The instructions walk you through it...

 

[Thermos]

Nothing against GAMI but they are very pricey and oriented toward the certified crowd. Give Don Rivera a call at Airflow Performance. He can help you for a lot less money

What Mark said. GAMI is overpriced for an E-AB application, in part because they live in the certified world. Give Don Rivera a call.

Dave

 

[GlennBfromOz]

Engine: Lycoming IO-360-A1A (2010 vintage)

I have big difference (150 deg.) between my coolest and hottest EGTs when leaning to LOP. I can't really operate LOP on all cyls. with this big
of a difference. After reading a few posts here of folks trying to adjust the flows themselves with different sized jets, so I don't know if I
want to fool with this so I'm considering purchasing a set from GAMI ( $850, https://gami.com/gamijectors/gamijectors.php ).
Anyone here done this on their IO-360 and are you happy with the results?

Phil,

It’s not the absolute value of EGT that matters. It’s where they peak in relation to one another, The number is heavily dependant on probe placement even when all other parameters are the same.

Case in point: one of my EGT values recently fell to about 300F less than the others, yet the engine ran fine and all EGTs still peaked at the same fuel flow. The cause was predictable, and apparent when I checked the relevant cylinder. The probe had slipped partway out of the mount in the exhaust pipe, so it was no longer protruding as far into the gas stream. Reinstalling it and tightening the B-nut restored the EGT to its previous number.

If one cylinder is reaching peak EGT before or after the others, you have an imbalance and some injector tuning (or, first, cleaning) is worthwhile.

Glenn

 

[Philz7A]

The actual temps are not the concern. Placement of the EGT sensors is never exact and will cause a difference in reported temps. As others have said Don at AFP is the go to...
The trick to LOP is fuel flow being close to each other when they peak.
I have an AFP system in my 6A's IO360B1F6 and run LOP with a spread of .01gph.
The instructions walk you through it...

Thanks recapen, that sounds great compared to mine! So I did swap the EGT sensors on cyls. #1 & #3 with virtually no difference afterward and I do show about .8 gph difference (correction) from the 1st to last EGT when setting LOP. Makes me think this is probably a fuel flow issue.

Hey Recapen, ".01 gph" spread? Wow that's close! My fuel flow shows only .1 gph increments which is close enough for me.
What brand/type of fuel flow sensor are you using?

 

[Philz7A]

Phil,

It’s not the absolute value of EGT that matters. It’s where they peak in relation to one another, The number is heavily dependant on probe placement even when all other parameters are the same.

Case in point: one of my EGT values recently fell to about 300F less than the others, yet the engine ran fine and all EGTs still peaked at the same fuel flow. The cause was predictable, and apparent when I checked the relevant cylinder. The probe had slipped partway out of the mount in the exhaust pipe, so it was no longer protruding as far into the gas stream. Reinstalling it and tightening the B-nut restored the EGT to its previous number.

If one cylinder is reaching peak EGT before or after the others, you have an imbalance and some injector tuning (or, first, cleaning) is worthwhile.

Glenn

Good info. Thanks Glenn!

 

[mfleming]

The actual temps are not the concern. Placement of the EGT sensors is never exact and will cause a difference in reported temps. As others have said Don at AFP is the go to...
The trick to LOP is fuel flow being close to each other when they peak.
I have an AFP system in my 6A's IO360B1F6 and run LOP with a spread of .01gph.
The instructions walk you through it...

So if I have this right, you note the fuel flow when the first cylinder peaks and then note when the last cylinder peaks and in your case that was .01 gph? What's a bad spread? Also, whose instructions? The AFP instructions?

 

[D-Dubya]

Thanks recapen, that sounds great compared to mine! So I did swap the EGT sensors on cyls. #1 & #3 with virtually no difference afterward and I do show about .5 gph difference from the 1st to last EGT when setting LOP. Makes me think this is probably a fuel flow issue.

Hey Recapen, ".01 gph" spread? Wow that's close! My fuel flow shows only .1 gph increments which is close enough for me.
What brand/type of fuel flow sensor are you using?

If you're already at 0.5 gph difference from the first to the last cylinder to peak, then you're pretty dang close to the target goal. That's assuming you're following the instructions correctly on how to do it. I've heard people say that they can get that to a spread of 0.1 gph with some effort. As others have said, find Don's instructions online and go fly at altitude to run a few iterations and confirm where your engine is performing. Mike Busch has written numerous articles on this as well. The basic principle is the same regardless of whose instructions you follow.

The statement of 0.01 gph may have been an unintentional misplaced decimal point. Even if the flowmeter were accurate enough to measure 0.01 gph, that would mean that all of the cylinders peaked simultaneously upon the slightest movement of the red knob at peak EGT. Realistically, that's not a repeatable measurement. If I'm wrong, I'm sure someone will correct me.

 

[recapen]

Misplaced zero...
I got to .1....
It's a standard red cube and AFS 3400 Engine Monitor.
Sorry for the confusion...

 

[Z32MadMan]

Pull all 4 injectors, reconnect them to the individual fuel lines, put clear cups under the injectors, then run your boost pump with throttle and mixtures forward for 20-30 seconds

Look at the shape of the stream and compare the cup quantities when you’re done. You can have an obstruction in the fuel lines, or more likely the fuel flow divider that would not be rectified by swapping or cleaning the injectors.

 

[Steve Watkins]

Another vote for Don Rivera at Airflow Performance. He got me sorted out quickly and only took a few tries to get dialed in. He had me swap all the .028" injectors to .024" first. Then ran the lean test and swapped 2 of the nozzles for slightly smaller ones. I think one is a .0235" and one is a .023". Runs great lean of peak now.

 

[recapen]

My first change was .028 to .024. Next annual, the squirt all 4 into individual bottles test showed one injector with a different stream than the other three...replaced that one.

Looking for an ultrasonic jewelry cleaner for regular cleaning...

 

[bjdecker]

Concur with what others have said: The GAMI juice isn't worth the squeeze; figure out the ∆FF between the peaks using the EGT, then adjust the restrictor up in size (peaks early - lean) or down (peaks late - rich) depending on what the behavior of that particular cylinder is. 0.1 ∆FF is what you're aiming for...

 

[Philz7A]

If you're already at 0.5 gph difference from the first to the last cylinder to peak, then you're pretty dang close to the target goal. That's assuming you're following the instructions correctly on how to do it. I've heard people say that they can get that to a spread of 0.1 gph with some effort. As others have said, find Don's instructions online and go fly at altitude to run a few iterations and confirm where your engine is performing. Mike Busch has written numerous articles on this as well. The basic principle is the same regardless of whose instructions you follow.

The statement of 0.01 gph may have been an unintentional misplaced decimal point. Even if the flowmeter were accurate enough to measure 0.01 gph, that would mean that all of the cylinders peaked simultaneously upon the slightest movement of the red knob at peak EGT. Realistically, that's not a repeatable measurement. If I'm wrong, I'm sure someone will correct me.

thanks Dubya. Ya I figured the .01 g/hr was a typo.

 

[Philz7A]

The actual temps are not the concern. Placement of the EGT sensors is never exact and will cause a difference in reported temps. As others have said Don at AFP is the go to...
The trick to LOP is fuel flow being close to each other when they peak.
I have an AFP system in my 6A's IO360B1F6 and run LOP with a spread of .01gph.
The instructions walk you through it...

So I went to the AirflowPerformance website and downloaded their Nozzle Tuning data instructions and recording sheet.
Recorded all the fuel flows starting at ROP and then reducing the GPH at 0.2 gph, taking the reading, reducing flow by 0.2 etc.
until all cyls reached LOP (as per instructions). First at 4500' and 24" mp @2400 rpm (my go to local flt. numbers), then at 8500'
and 22.1" @2400, and then last 3500' and 22.1" @2400. Cyls. 2, 3 and 4 were all within .2 gph of each other.

My results (4500'):
Cyl. #2 reached LOP (1st) at 1428 deg. EGT then,
Cyl. #1 reached LOP (4th, last) at 1493 deg. EGT with a .7 gph spread. Got a .8 gph spread at the lower power setting at
3500' and 8500'. Obviously cyl.#1 running relatively rich.

Sent my results (emailed) to AirflowPerformance and they suggested 1 new restrictor (jet) for cyl. #1 of .027" (orig. restrictor is
brass and no groove is an Airflow/API .028).
So for only $38 (1restrictor) plus shipping, I should have a much more matched fuel flow. I'll get back and post the results after
I get it installed.

What I learned:
Originally before I understood what was going on, I thought that cyl.#1 was lean due to the 100 deg.+ hotter temp than the cooler
EGTs. WRONG! As I learned it was actually the richest. What? So like Airflow says, ignore this. Probably just slightly different
EGT probe placement in the exhaust manifold (as far as I can figure out). Cyl. #1 probe was not lying because I swapped it with
#3 and the temps were about the same afterward.

Thanks to everyone who posted on this to help me understand the problem!

 

[lr172]

).
So for only $38 (1restrictor) plus shipping, I should have a much more matched fuel flow. I'll get back and post the results after

a big shout out to don at afp. I think i payed 30 some odd dollars per restrictor back in 19. I think we may have found the only company that hasn’t doubled their price just because they can.

Thanks Don!