Helicoil for a '66 20hp

[kfa4303]

Hi all. So after much effort and many trips to the store for various and sundry nuts and bolts, I replaced all of the gaskets in my powerhead and put the entire motor back together. Just as I went to install the spark plugs to fire the old girl up, I stripped the threads in the upper spark plug hole :facepalm: Can I put a helicoil in to repair it, or is there some way to re-tap the hole itself? Thanks.

 

[82rude]

Re: Helicoil for a '66 20hp

I used a helicoil on my 1967 20hp Chrysler with zero issues.

 

[boobie]

Re: Helicoil for a '66 20hp

Get the helicoil. I've done a lot of them over the years and had good luck. Just make sure you tap it straight.

 

[kfa4303]

Re: Helicoil for a '66 20hp

Great news! I was hoping I could use one. Of course, everything else on the motor is good to go and has never been better. Where should I look for a helicoil any way? Do they sell them at autoparts stores? Do I need a specific size, or are they standardized? Thanks again.

 

[boobie]

Re: Helicoil for a '66 20hp

Yes, parts houses have them. Just get the right length for the spark plug you have.

 

[kfa4303]

Re: Helicoil for a '66 20hp

Awesome! One more thing, will I need to remove the head, or can I do it in situ? Thanks again.

 

[bonzoscott]

Re: Helicoil for a '66 20hp

I had to do this once on an 85 HP. Or, lets say I had it done. From what I can tell, it cost $25 for one size Helicoil kit. Take the head off and take to a machine shop. They will do it right and although it was 20+ years ago, they charged me only $15. Probably $25-30 now.

 

[boobie]

Re: Helicoil for a '66 20hp

I've done them with the head on, but put plenty of grease on the tap to catch the shavings. They will stick to the tap.

 

[itsaboattime]

Re: Helicoil for a '66 20hp

Pull the head.

You can put it in a vise that way and make sure you start the tap straight. When I install heli coils I use red loc-tite to keep it in place.

 

[AlTn]

Re: Helicoil for a '66 20hp

would only add to make sure the helicoil is for an aluminum head

 

[kfa4303]

Re: Helicoil for a '66 20hp

Will do. I've been doing some research and I've see some folks use Permatex hard gasket sealer on the outside of the helicoil itself. Does that sound right? Also, I've seen several different brands of "helicoil" does it matter which one I use? Thanks again.

 

[jasper60103]

Re: Helicoil for a '66 20hp

I've had success with Save-A-Thread and red loctite. Good luck.

 

[kfa4303]

Re: Helicoil for a '66 20hp

Thanks again Jasper. I'm assuming you apply the Loctite to the outer threads right in place of the Permatex gasket sealant. I've also seen what look like 2 different types of kits. Once seems very simple, with little more than a tap and insert while the other come with more components. Does it mater which I use?

Amazon.com: Powerbuilt 648421 14MM Spart Plug Thread Repair Kit: Automotive
http://www.amazon.com/Permatex-82194-High-Torque-Silicone-Gasket/dp/B000HBGI8K/ref=pd_sim_auto_3
vs.

Helicoil 5334-14 Save-A-Thread Thread Repair Kit M14 x 1.25 : Amazon.com : Automotive

 

[jasper60103]

Re: Helicoil for a '66 20hp

Thanks again Jasper. I'm assuming you apply the Loctite to the outer threads right in place of the Permatex gasket sealant. I've also seen what look like 2 different types of kits. Once seems very simple, with little more than a tap and insert while the other come with more components. Does it mater which I use?

Amazon.com: Powerbuilt 648421 14MM Spart Plug Thread Repair Kit: Automotive
Permatex 82194 Ultra Grey Rigid High-Torque RTV Silicone Gasket Maker, 3.5 oz. : Amazon.com : Automotive
vs.

Helicoil 5334-14 Save-A-Thread Thread Repair Kit M14 x 1.25 : Amazon.com : Automotive

I applied the loctite to the outside threads of the insert. Then screwed it in and tapped in place.

edit: Yes, they recommend high temp RTV silicone on the package, but I used Permatex High temperature threadlocker red instead.

 

[slate1234]

Re: Helicoil for a '66 20hp

only ever used one on my thermostat cover I stripped the thread, I used helicoil and they seem very strong it didnt say anything regarding loctite ect so I didn't use any, if it was needed surely they would either supply it or recommend useing it

 

[slate1234]

Re: Helicoil for a '66 20hp

just found this hope it helps: fulltorque.com/

 

[kfa4303]

Re: Helicoil for a '66 20hp

Hmmm....... I've seen methods using sealant/loctite and without it :/ I trend to agree that they would include it in a kit, but we all know what happens when we "assume" too much. I'll keep doing a bit of research and see what's available in town. Do any of you happen to know the thread count of a standard Champion J6C spark pug? Thanks again.

 

[Ibl0wstuffup]

Re: Helicoil for a '66 20hp

How hot does the head get? Heat is how you release red lock tite so that's probably why they say to use high temp rtv.

 

[boobie]

Re: Helicoil for a '66 20hp

If you can find it the Green Loctite is made for high temp applications.

 

[kfa4303]

Re: Helicoil for a '66 20hp

HI all. So I tracked down a "sav-a-thread" kit. It looks like it will work well and apparently you can use it without removing the head. However, it does say to use "high temperature RTV silicone" on the outer threads of the helicoil itself. Does it matter which brand I use? I've seen some red Permatex that looked like it may do the job. Thanks again.