I need a lesson injectors. Lol... fixed after auto correct

[xcrmckenna]

 

I have a Lycoming IO-360. We just cleaned my injectors and the threads on one of them was or got a little Boogered up and I can’t get the fuel line on it. In the morning I’ll find a nut to go on it hoping to fix the threads.

 

If that fails I’ll need a new injector. “Or buy a set of Gami’s” Two of the injectors have a large A on them and the other two have a small A stamped on them. I was wondering what that signifies and what the best way to identify them is and how to order them.

 

I don’t know where I got it but I thought injectors were stamped with dots but mine are not.

 

Thanks for any help and the added education.

 

 

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Edited May 2, 2021 by xcrmckenna

[Hank]

A picture is worth a thousand words . . . .

I can't help anyway, I don’t have any injectors to compare against. 

[EricJ]

1 hour ago, xcrmckenna said:

If that fails I’ll need a new injector. “Or buy a set of Gami’s” Two of the injectors have a large A on them and the other two have a small A stamped on them. I was wondering what that signifies and what the best way to identify them is and how to order them.

I think there's only one nozzle assembly part number from Lycoming for the IO-360 engines, so there isn't much to worry about or pick from.   The 'A' stamp is the nozzle size/flow rating, and I don't think the size of the letter matters.  It probably just means they were made on different days and one of the stamp dies got changed out.   The fact that it is an 'A' is the important part, and I don't think there are any other stock options for the Lycoming IO-360.

Lycoming Service Instruction 1532K supposedly shows the latest part numbers for the injectors, manifold, or assembled nozzle.   If you buy the entire assembled nozzle the part no. is LW-18265.

My understanding has always been that the Lycoming intake is balanced well enough that GAMI injectors aren't very productive compared to the stock injectors.   Continental intake manifolds have less well balanced intakes and benefit more from GAMI injector adjustments.

[carusoam]

I like posting after Eric...  he covers so much detail, correctly, and completely... 

 

So....

Charles,

1) if you have ever ran a Gami spread test... and got numbers that were close to zero... and uniformly spread out... from first to last...

Your need for Gami injectors would be nil...

The four cylinder Lycoming is so well balanced because the cylinders are all fed the same way with equal length intake tubes...

The six cylinder engines aren’t so lucky...  getting the equal length intake tubes takes a few curvy pipes... 

 

2) The A on the fuel injector is also the alignment mark... (aligning the vent hole on the fuel injector is important when putting it back together...   I believe the A gets used as the reference...

3) My first Continental IO550 had a Gami spread of 0.1 gph...   they all peaked very close to one another...  leaning deep LOP... never showed a sign of roughness... it just went lower in power until it just shot off...

Really weird if you are expecting roughness... 

A previous owner may have spent a few extra dollars getting that to work so well...

 

I’m only a PP, I may not have added anything of value to the conversation...

Best regards,

-a-

[xcrmckenna]

2 hours ago, Hank said:

A picture is worth a thousand words . . . .

I can't help anyway, I don’t have any injectors to compare against. 

Hank, 

its never to late to bring something home with injectors...:) 

[xcrmckenna]

Sorry everyone, 

I shouldn’t have started a thread right before date night with the better half. And now she is wondering about my lesions...:)

 

As always thanks for the help! I do run LOP easily my spread is never more than .2 when I rapidly lean it. Here is a pic of the threads. 

[N201MKTurbo]

How do the threads look on the B- nut? It takes two to get cross threaded. I always start them with my fingers Before I put a wrench on them.

[xcrmckenna]

How do the threads look on the B- nut? It takes two to get cross threaded. I always start them with my fingers Before I put a wrench on them.

I took the fuel line off the spider and both sides of the fuel line go into the spider just fine. I think the injector might have got the messed up when we were shaking it in the cleaning jar with the gun cleaner and mineral spirits.


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[Hank]

It looks like just the first thread is messed up, the really shiny one. That will prevent anything from screwing onto it.

Do you know a machinist? This is a perfect candidate for a thread repair file, generally square with different thread pitches on each face, generally with both ends different, too.

[xcrmckenna]

I ordered a new injector and a die. If I can’t cut clean the threads on the old injector then I’ll replace it.


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[carusoam]

Spare injector goes in the flight kit in the back... next to the spare plug...

If you have a spare... you will never need it...   (which is nice)

-a-

[A64Pilot]

A die will clean it up, at first I cringed, but it doesn’t look bad at all.

‘I put Gami’s on two engines, an IO-540W1A5D and a Continental IO-520, forget which one. But it was a waste of money for both, neither needed them, nothing improved.

The fine wire plugs on the other hand did make a difference, but I’ve heard others have had issues with fine wires.

‘I prefer a die to a file, less skill required, but if your good a file works too.

Edited May 2, 2021 by A64Pilot

[Hank]

5 minutes ago, A64Pilot said:

A die will clean it up, at first I cringed, but it doesn’t look bad at all.

. . .

I prefer a die to a file, less skill required, but if your good a file works too.

Dies are great, but they will only do one size. A thread repair file typically has eight threads on it, and diameter doesn't matter. For those without skill / practice, give your machinist buddy a few bucks or lunch to do it for you using die, file or something special from his bag of tricks.

[PT20J]

Note that the A is supposed to point down so that the bleed hole doesn’t drip gas. Next time, just soak them - there’s no need to shake

Skip

[Yetti]

I had that issue so I ordered a new fuel line too. Probably should have ordered the other three.  I have hand recut threads on a bike bottom bracket with a properly cut tool steel from a lathe blank.   Of course it was the night before a race, so had to be done.

[gsxrpilot]

I've seen JD use a thread repair file. It's amazing what that tool can accomplish in skilled hands.

[xcrmckenna]

A die will clean it up, at first I cringed, but it doesn’t look bad at all.
‘I put Gami’s on two engines, an IO-540W1A5D and a Continental IO-520, forget which one. But it was a waste of money for both, neither needed them, nothing improved.
The fine wire plugs on the other hand did make a difference, but I’ve heard others have had issues with fine wires.
‘I prefer a die to a file, less skill required, but if your good a file works too.

I haven’t had any issues with my fine wires but I didn’t really notice any improvements with them. I’ve lead fouled one I think because I fly a lot of LOP and the cylinders run really cool. I tried the file but gave up I was worried I would end up doing more damage to the threads and a die wouldn’t be able to save it:)


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[xcrmckenna]

Note that the A is supposed to point down so that the bleed hole doesn’t drip gas. Next time, just soak them - there’s no need to shake

Skip

Sweet! Thanks for the installation info. That would have been missed on us. One of the injectors I know has the A on the bottom, I’ll make sure I check the other two and install the new one that way.


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[xcrmckenna]

I've seen JD use a thread repair file. It's amazing what that tool can accomplish in skilled hands.

I tried using a double bevel chainsaw file I JD at the shop but to no avail, so I’ll use the die. Hopefully that will get me going. If not a new one will go in


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[xcrmckenna]

Crisis averted!!! We managed to save the damaged injector and save $280 with a new one. If anyone is wondering the thread and pitch on the lycoming IO-360 injectors thread and pictures is it’s 5/16x32



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Edited May 11, 2021 by xcrmckenna

[Bartman]

Good on you for saving it !!!

Similar story...

After my engine rebuild all 4 injectors would only go in a couple of threads, probably due to paint, so I ran a tap to clean. I’m pretty sure it was 1/8 pipe thread on the other end. 

[carusoam]

Great follow up, Charles!

Best regards,

-a-