Hi guys-on my 70 the 2 bolts that hold down the thermostat housing 1 bolt on my aluminum intake is striped is there a fix for this, thanks for the help

 

A helicoil will fix it.

 

Thanks 62corvette but not sure what a helical is, never had to use one

 

 

Since that bolt is going into a water passage, you will need to seal the Helicoil AND the bolt going into it. Usually, one would use Loctite on the Helicoil; but that won't seal water. You might need to use some epoxy on the outside threads of the Helicoil when you insert it. Be sure to wipe out any that gets into the inside threads....or chase it with a thread tap after the epoxy hardens.

 

I have installed them using Permatex "Hi-Tack" as a sealer and never had a leak.

 

Actually anerobic thread sealer which loctite is a form of will work. It is used with lock n stitch pins (1/4-20 bolts) to seal cracked blocks.

 

Loctite is brittle when hardened. Heat cycling can fracture brittle 'stuff' rather easily. Can't say it wouldn't work, though, as I have not tried it.

 

If you go the Heli-Coil route, once the epoxy has hardened, consider putting grease on the flouts of the tap to capture any epoxy pieces. You do not want to introduce them into the cooling system. Jerry

 

Doing a Heli-Coil for the first time is not that exciting or difficult a job. Just go someplace like a NAPA store and they will have the proper size "kit" for the size of the bolt that stripped. The kit will have a "drill bit" to make the hole the right size and a "Tap" that threads the hole and an "Insert Tool" for installing the heli-coil in place. After you install the Heli-Coil you need to break off the tab used in the installation which is scored and breaks off easily. The trick is to use a long nose Needle Nose pliers to remove it when you break it off. If it does drop you can pick it up inside the manifold below the thermostat, just try and not drop it.

I "used" to build high horsepower Air Cooled VW engines and we used to install heli-coils for the spark plugs and the bolts that held the engine together. A "Boxer" style engine is a "split-case" that has pistons pushing in and out horizontally and the stress of extra HP required hell-coiling the holes before they stripped out.

Before inserting the Heli-coil I would use RED Locktite and coat the outer threads like I have for hundreds of heli-coils. I only had one spark plug ever come loose while working on VW's and that was due to the Locktite not bonding properly. This taught me to clean the holes with a alcohol wipe before putting on the Locktite.

 

THANK YOU guys all of you I have a friend that works for Napa and pretty smart he will take care of me

 

Another option is to drill and tap it to the next size up or close metric equivalent. Of course then you'd have two different size bolts in the thermostat housing.

 

I should mention why this issue happens from time to time, so it does not repeat itself.

There is not a lot of torque requirement for those water-neck bolts. 20? 25? Especially in soft aluminum.
But what happens somewhat often is, the wrong bolt was used. (Something from the junk drawer of your shop maybe?)

As you know, each bolt is of different length. The best method for double checking proper length is to install the bolts w/o the water-neck and just snug them in the bottom of the hole. Then, slide your water-neck up next to the bolts. Are the bolts too long?
Even a smidge too long will allow a weep of coolant. So the average Joe snugs the bolts again. Still leaks. Another snug and so on.

If its cast iron Intake, the bolt may snap off. But on a aluminum Intake, you will pull the threads.
So tell Joe to check the bolt length.

 

IMHO - "While You're at it" - take a good look at the threads on the other ("good") thermostat housing bolt hole. If they look like metal has been "eroded" over time - heli-coil that one at the same time.

 

Do em both. Then install studs.