AZ Helicoil problem

pmanton

pmanton

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I'm in the middle of an annual on a C-85 engine equipped aircraft at the Buckeye Airport. KBXK. The owner boogered up the helicoil on cyl #1 upper spark plug hole. I don't have the tooling to replace the helicoil. Is there an A&P with the proper tooling who would travel to Buckeye and do the repair on the plane?

Paul
Salome, AZ
 
pmanton said:
I'm in the middle of an annual on a C-85 engine equipped aircraft at the Buckeye Airport. KBXK. The owner boogered up the helicoil on cyl #1 upper spark plug hole. I don't have the tooling to replace the helicoil. Is there an A&P with the proper tooling who would travel to Buckeye and do the repair on the plane?

Paul
Salome, AZ
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The tooling usually comes with the helicoil kit.
 
My oral surgeon has an awesome set of tools. He just extracted one of my molars and put a helicoil in there.
 
flyingron said:
My oral surgeon has an awesome set of tools. He just extracted one of my molars and put a helicoil in there.
Click to expand...

I didn't like it when he used a sledge hammer and splitting wedge...
 
pmanton said:
I'm in the middle of an annual on a C-85 engine equipped aircraft at the Buckeye Airport. KBXK. The owner boogered up the helicoil on cyl #1 upper spark plug hole. I don't have the tooling to replace the helicoil. Is there an A&P with the proper tooling who would travel to Buckeye and do the repair on the plane?

Paul
Salome, AZ
Click to expand...

I don't believe they are regular helicoils, they are known as cylinder savers. and they require machining the cylinder head to put them in.
 
Tom-D said:
I don't believe they are regular helicoils, they are known as cylinder savers. and they require machining the cylinder head to put them in.
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Tom ... I've never had to use one. Can you outline the process for installation and what machining is required?

Thanks

Jim
 
Luvrv8 said:
I have seen both the helicoils and the savers. As for the helicoil, I bought a kit with the installer and now we get coils as needed. Most of the shops on our field have them.

http://www.aircraft-tool.com/shop/detail.aspx?PRODUCT_ID=4260-18
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If I recall right, the small Continentals have bronze inserts threaded into the head and the inside is staked or rolled over (like a brake rivet) to keep them there. I dont think there is enough meat to helicoil that thing.

Tom D might know.

Lycomings come with helicoils in the aluminum head.

Dan
 
The "helicoil" kit comes with a tap, the collar for the helicoil and the driver....
Chase the threads with the tap.. If they are ok. load a new 18MM helicoil into the collar and install.. You are lucky it is a top spark plug hole.. The lower ones are a bit harder to fight with....

Ps... Any NAPA ( National Aviation Parts Assoc) store has the helicoils and the entire kits.. They are NOT that expensive....:nonod:
 
Lycoming has a replacement helicoil that is .003 oversize which is to be used if the original coil comes out.
 
Dan Thomas said:
If I recall right, the small Continentals have bronze inserts threaded into the head and the inside is staked or rolled over (like a brake rivet) to keep them there. I dont think there is enough meat to helicoil that thing.

Tom D might know.

Lycomings come with helicoils in the aluminum head.

Dan
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The C- series all have a steel threaded insert in the spark plug hole. If this has been helicoiled once don't do it again.

The second helicoil and spark plug will blow out.

But do as you like ,,,,, I'm not signing it off. :)
 
I should have said right off--these are Millennium cylinders. The plane is 2 hours away. The owner is trying to avoid 2 hours travel-remove cylinder--2 hours travel replace cylinder--new rings--mineral oil--break in--etc.
I'm trying to get out of it also. :)
Paul
Salome, AZ
 
pmanton said:
I should have said right off--these are Millennium cylinders. The plane is 2 hours away. The owner is trying to avoid 2 hours travel-remove cylinder--2 hours travel replace cylinder--new rings--mineral oil--break in--etc.
I'm trying to get out of it also. :)
Paul
Salome, AZ
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How bad is it screwed up that it can't ferry? The thing is it's all high risk to do leaving the jug on because of desbris getting in the cylinder, especially on a top plug.
 
I have had a lot of luck using a file to repair the thread. When that attempt failed I sent the cylinder away.
 
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