Stripped threads on intake
Thread Starter
Safety Car
Joined: Jun 2005
Posts: 3,841
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From: Inver Grove Minnesota
Stripped threads on intake
I striped out the threads on my water neck. I know there are some sort of thread inserts but I'm not sure what they are called. Would that work? Or am I going to be buying a new manifold soon?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
They are called Heli-Coils. Most local parts stores will carry most sizes of them.
It would almost be better to take the manifold to a local machine shop, or do the work yourself, and drill and tap a size larger. Enlarge the holes in the neck, and bolt back down.
It would almost be better to take the manifold to a local machine shop, or do the work yourself, and drill and tap a size larger. Enlarge the holes in the neck, and bolt back down.
Race Director
Joined: Jul 2004
Posts: 12,696
Likes: 329
From: Scottsdale Arizona
Helicoil is the brand name. Pretty easy to use, especially in aluminum. Buy the kit and it comes with the tap and tool. Drill out the old hole, rethread and insert the Helicoil. Good as new.
Drifting
Joined: Jul 2002
Posts: 1,944
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From: The only Corvettes in Highett Victoria
bolt size
Justin,
The bolts are 3/8" UNC about an inch and a quarter long standard, but just take your old ones to the shop and get two 7/16" the same length and a Helicoil kit to suit that size. Don't forget to enlarge the holes in the water neck accordingly. If you're regularly pulling your water neck off, you should think about putting in some studs and Locktiting them in and use nuts to secure the neck.
Regards from Down Under
aussiejohn
The bolts are 3/8" UNC about an inch and a quarter long standard, but just take your old ones to the shop and get two 7/16" the same length and a Helicoil kit to suit that size. Don't forget to enlarge the holes in the water neck accordingly. If you're regularly pulling your water neck off, you should think about putting in some studs and Locktiting them in and use nuts to secure the neck.
Regards from Down Under
aussiejohn
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
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Drifting
Joined: Jul 2002
Posts: 1,944
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From: The only Corvettes in Highett Victoria
.........."and that's not all........"
Thanks, D-boy, and here is another little trick if you pull the water neck off often. That is to machine an O-ring groove in the water neck (or manifold, but the neck is easier) so you never have to "glue" a gasket on (to ensure a leak-free fit) and the resultant scraping off when you open it up. Just clean the O-ring and re-fit it.
Regards from Down Under
aussiejohn
Regards from Down Under
aussiejohn
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
It's 3/8" x 16, very common size.... the set is $19.98 at AdvancedAuto, just bought a set two days ago 
They recommend a very uncommon drill size for the 3/8 insert, in aluminum you can drill 3/8" which is 9.5mm. It works fine, actually pefect..... the drill size that they recommend is about 9,8mm (.012" larger) - if drilling in steel I'd use a 9.8mm drill bit, for aluminum (softer) the 3/8" is perfect
They recommend a very uncommon drill size for the 3/8 insert, in aluminum you can drill 3/8" which is 9.5mm. It works fine, actually pefect..... the drill size that they recommend is about 9,8mm (.012" larger) - if drilling in steel I'd use a 9.8mm drill bit, for aluminum (softer) the 3/8" is perfect
Racer
Joined: Dec 2006
Posts: 417
Likes: 40
From: Swansea IL
Do yourself a favor and take the thermostat housing and drawfile the bottom of the unit to make sure it is flat. That way, once you reinstall everything, the gasket will have a better chance of sealing. Plus, the housing bolts were probably over tightened in order to keep fluid from leaking. Just a guess there.
Bob
Bob
Thread Starter
Safety Car
Joined: Jun 2005
Posts: 3,841
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From: Inver Grove Minnesota
I was torquing them to the specs said in the intake intructions and one of the bolts stripped. This was when I first put it in. I might just buy a new housing while I'm at it.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Thanks, D-boy, and here is another little trick if you pull the water neck off often. That is to machine an O-ring groove in the water neck (or manifold, but the neck is easier) so you never have to "glue" a gasket on (to ensure a leak-free fit) and the resultant scraping off when you open it up. Just clean the O-ring and re-fit it.
Regards from Down Under
aussiejohn
Regards from Down Under
aussiejohn
Also great info. I buy and install O-ring water necks on all my Mopar motors...I wish they were as easy to find for GM.
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
I just bought one of their MrGasket chrome and O-ring necks, less than $10
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Aluminum does not lend itself to repetitive use.
VW has put helicoils in their production engines for years to prevent this from happening. Studs as others have suggested is a good solution too.
VW has put helicoils in their production engines for years to prevent this from happening. Studs as others have suggested is a good solution too.
Safety Car
Joined: Oct 1999
Posts: 4,101
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From: NorCal
http://www.ondrives.com/products.asp?recnumber=437
Never had one fail.
Hans
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
When I built large bore high compression VW's, we used these on the cases for the head/barrel studs:
http://www.ondrives.com/products.asp?recnumber=437
Never had one fail.
Hans
http://www.ondrives.com/products.asp?recnumber=437
Never had one fail.
Hans
That's a cool site to have on link, thanks.
