Stripped aluminum threads in intake [Archive] - Team Camaro Tech

: Stripped aluminum threads in intake

Nov 26th, 01, 05:23 AM
The distributor hold down bolt hole in my aluminum intake manifold is stripped and just spins when I try to tighten it (Can't get the timing to hold). I was thinking about putting a stud into the hole with something like JB Weld to hold it until I can remove the manifold and tap the hole.

Any other ideas? Do you think the JB weld (or another similar product) will work?

Will I have any problems cutting new threads into the aluminum when I have the time to remove it and tap it?



Nov 26th, 01, 06:28 AM
tappping it will not fix your problem. You'll need to go to the next size bolt and as long as you're doing that you might as well helicoil it first. Most good auto parts stores sell helicoil kits for various size bolts. It will come with an oversize drill and tap and a threaded steel insert and insertion tool. Just drill the hole oversize and tap it, then screw the helicoil onto the insertion tool and thread it into the hole until the small tang bottoms out. You'll have to remove your distributor, but that's no big deal. The threads will be fixed permanently and that's what you're looking for. It's real easy to do.

Nov 26th, 01, 06:56 AM
Kevin has a very good suggestion, and there are other routes to take.

One would be to drill thru the intake and through tap the threads, use a threaded rod and use it as a stud for dist hold down. Seal the threads with gasket sealant. Could even put a nut on the valley side of intake and lock in the threaded rod.

Everett 68/350/PG/11.90/115mph

Nov 26th, 01, 07:33 AM
I have the same problem on my intake. I just screwed a longer stud into the hole and got into the undamaged threads farther down. I don't expect the remaining threads to hold forever and I know they'll strip at the worst possible time. Even so, it was an easy temporary fix for me and I will most likely heli-coil the hole one of these days.

That brings up a question. I have not actually checked prices on heli-coils lately but I believe they are fairly pricey? Like $10 per fix or more? My manifold was apparently owned by someone who overtorqued almost every bolt. I've used the longer bolt/stud trick on most of the holes. Heli-coiling all of them could get expensive! I suppose I could drill them out and re-tap the next size but then I have to also enlarge the holes in the carb base and thermostat housing and brackets, etc. What a pain!

'69 400SB, Richmond 5-speed (

Nov 26th, 01, 07:41 AM
Thanks for the replies so far.
I've never used the heli coil before. Don't you have to buy an installation tool for like 80 bucks to put one in?

I was looking for the cheap quick fix until I have the time to take the intake off and repair it correctly.

Sounds like I should try the longer bolt (Duh!). How far down does the hole go? Will it bottom out on the bottom of the intake and wreck whats left of the good threads if I try something to large?

Nov 26th, 01, 07:51 AM
You can buy the heli coil kit for around 35.00. The idea of drilling all the way thru and putting a nut on the bottom side scares the hell out of me. If the nut comes off then you buy an engine instead of a heli coil kit.

Nov 26th, 01, 09:05 AM
That's why one uses J B Weld on the nut to hold it in place and/or screw-up the threads so the nut fits tight, as in a homemade locking nut?

Some of the better auto stores sell Heli-coil kits for under $20. Use the kit's tap and supply your own drill bit. Comes w/installing tool and some (usually 8) inserts.

Be sure to coat threads with antiseize for removal next time.

Everett 68/350/PG/11.90/115mph

Nov 26th, 01, 09:40 AM
Stick with the heli coil

Allen M
Nov 26th, 01, 01:37 PM
Don't use a Helicoil!!! Timeserts are better. They are threaded steel cylinders not springs like the helicoil. I think the Mac Tool truck sells them.

Nov 26th, 01, 01:56 PM
Just use a helicoil and stop jerry rigging everything, all those other ideas are pretty ridiculous, 30 bucks isn't that much money, when you are done you will never have to touch it again. Trust me I am a fellow cheap skate, but 30 dollars is not that much, it is really easy, just make sure you take out the dist. and stick a rag in the hole so no shavings get in the engine from drilling.

Nov 26th, 01, 03:11 PM
I have a drawer-full of Helicoils - never know what you're going to find on other people's cars. The 3/8"-16 Helicoil kit is $23.00, and includes 12 Helicoils, the tap, and the insertion tool. All you need besides the kit is the correct size drill for the tap (25/64" for the 3/8"-16 Helicoil). Not a big deal - takes about 5 minutes, lasts forever. Just be sure and drill a nice perpendicular hole for the tap, or your bolt will wind up crooked.

'69 Z28 Fathom Green

Nov 26th, 01, 07:25 PM
The nice thing about the heli coil is it will not strip ever again. You can anchor them in with some lock tite, and once they are installed, you will bust the head off a bolt before you strip the helicoil, honestly, we tested it in tech school. I work on small engines, and one would be surprised at how many home-jobbers over torque the steel bolts or sparkplugs into aluminum blocks. Heli coils are really quick to install, and they last a lifetime. The only tricky part can be when busting off the insertion tang. Sometimes they are stubborn and mess up the coil, but it's only a 50 cent mistake anyway. When I last had my aluminum intake off the car, I took the time to insert heli coils into the 4 carb bolt holes, even though they were not yet stripped. I never thought of the distributor clamp down hole, but next time around I should coil that one too.

Nov 26th, 01, 09:52 PM
trust me and just about everyone else here. You can not go wrong with the helicoil and it's a permanent fix. I have never seen one fail or go bad and they're so easy to install. They're good enough to come out of the factory on the turbine engines and 24 million dollar airplane I crew chief then they'll work good on a 200 dollar Chevy intake. Twenty two years in aviation, 20 on jets and I've never seen one fail. Don't fall into this trap of cobbling things up to make them work, it only comes back to haunt you later.

Nov 27th, 01, 02:30 AM
Quite the controversy on this thread (sic).

As the majority of you suggest, a Heli-coil is the correct route to go, cheap, $20-$23 for the inital start-up, easy to install, as long as one drills a perpendicular hole, and will last a long time, one act of correction not coming back to bite you in the butt!!!

Forgive me Father, for I gave a suggestion to fix that was cheap and very economical. I have done this act (art) of correction to the manifold and it has served me well. PLease forgive me (I am bowing and my clasped hands above my bowed head).

I'll buy the next round of cold drinks. May I have your order?

Everett 68/350/PG/11.90/115mph

Nov 27th, 01, 02:48 AM
Duct Tape is cheap fix also!!!!!ask Red Green

Nov 27th, 01, 03:12 AM
Okay - Okay - Heli Coil it is! Dare I ask if anyone has any suggestions on how to drill the hole straight while the intake is still in the car?

(How about if I used some JB Weld at the base of the hole to and then some duct tape to hold the drill straight - this way everyone is happy!)

Thanks again for all the help.

Nov 27th, 01, 03:36 AM
Very carefully HE HE When you drill for the heli coil it won't be that much larger of a hole. Just take your time it's a peice of cake. Origonal hole will work as guide.

Nov 27th, 01, 07:34 AM
Snap-on makes a nice angle drill set for around 70 bucks, I don't know if the bits go large enough, I'll check mine. But then we're driving up the cost of the repair quite a bit.

Nov 29th, 01, 07:26 PM
Stripped hole sounds like a good reason to buy a new intake!!!

Nov 29th, 01, 07:38 PM
When you throw away all them parts cause they have a stripped hole call me I'll take em!!!!

Nov 29th, 01, 11:26 PM
Heh, no doubt! I cannot imagine tossing a perfectly good aluminum intake because it has a stripped hole :lol: What would one rather spend: $30 on a heli coil that will last forever, or $250 on a new intake???

Nov 30th, 01, 10:25 AM
new intake!

Nov 30th, 01, 08:04 PM
ryanman250- You aren't looking at the big picture! The stripped hole is on top of the ENGINE- Therefore, a BIGGER brand NEW engine is preferred, not just the intake. That way, ALL the bolt holes are new.

76 Camaro/mild 350 .030/M21/Z28 body parts/lotsa other goodies

[This message has been edited by XK1 (edited 11-30-2001).]

Nov 30th, 01, 08:33 PM
Now you've got it heck with the JB Weld,heli coils,duct tape ETC. Get out the check book MA!! were buyin BRAND NEW.

Dec 1st, 01, 07:14 PM
sounds like a plan!!!

Dec 2nd, 01, 07:25 AM
I know this has been beat to death but you can install any size helicoil with just a good pair of needle nose pliers. No special tools needed.
If the boss is big enough I would tap it out 2 sizes bigger, get a stainless stud and drill and tap the center of the stud the size you need then screw the stud in with green loctite. We do this all the time in tooling work. You get steel threads that are better than the helicoil and better than the aluminum was when new.

1969 Camaro 350 & 1969 Impala SS 427/ 4-speed (restored)

Dec 2nd, 01, 02:58 PM
I've tried it with needle nose, correct tool works much better.