Heli-coil installation?

[maverick974]

Ok, as you can see by my last thread, I checked my compression. 125 on all cylinders. Pretty happy about that.
Unfortunately, my bottom plug hole is stripped out. I'm going to install a heli-coil.
Do I need to take the head off to prevent shavings into the combustion chamber or can I leave the head on. If a few shavings get in there, will they just blow out the exhaust?
Never done a heli-coil before.
Thanks again for the help.

Oh! It's a 1984 Force. 85 hp.

 

[Frank Acampora]

Re: Heli-coil installation?

I have at various times purchased a couple of junkers that had heli-coils installed in the plug holes----I was not impressed. In fact, I was not even pleased. It is just a crappy way to salvage an un-useable head.

Unless money is so tight that you absolutely want to do it, I suggest buying a used head for only a couple of dollars more than the cost of the heli-coil and installation tools. Just keep an eye out on the auctions.

If you absolutely must use one, do remove the head. Even though it is only aluminum it is always better to not have any chips inside the cylinder. And try to find the flanged brass inserts. They are a different brand and will not migrate out of the threads as Heli-Coils will--even though they say they won't.

 

[AviatorJim]

Re: Heli-coil installation?

Airplane engines are made with heli coils for the sparkplugs, and they need to get replaced once in a while. Pack the tap with grease when you cut the threads, and it will hold all the shavings. Have the piston high enough up to close the ports, and be on the compression stroke to close your valves if it is a 4 stroke. Then you can blow out any chips that you miss with compressed air.

Put in the heli coil with a drop of locktite, and use a little copper antisieze when you put in the sparkplugs so you don't pull the coil out the next time you pull your plugs.

You don't need to drill out for the tap when you are doing a sparkplug. The old hole is big enough, and the aluminum is soft enough.

Good luck.

 

[JB]

Re: Heli-coil installation?

I much prefer Time-Serts over helicoil. Better heat transfer.

 

[halfmoa]

Re: Heli-coil installation?

Airplane engines are made with heli coils for the sparkplugs, and they need to get replaced once in a while. Pack the tap with grease when you cut the threads, and it will hold all the shavings. Have the piston high enough up to close the ports, and be on the compression stroke to close your valves if it is a 4 stroke. Then you can blow out any chips that you miss with compressed air.

Put in the heli coil with a drop of locktite, and use a little copper antisieze when you put in the sparkplugs so you don't pull the coil out the next time you pull your plugs.

You don't need to drill out for the tap when you are doing a sparkplug. The old hole is big enough, and the aluminum is soft enough.

Good luck.

This is the best heli-coil advice I've ever read. Bravo!