Stripped intake manifold, C3 SB

[Ed Driscoll]

Hi Guys,
One of the four holes tapped to receive the carb bolts is stripped (in the intake manifold). I've seen this dealt with by drilling out to the next size and re tapping, then inserting a tapped sleeve into the hole, thus bringing the hole back to it's original thread size. The problem is that I can't find these inserts or a kit with drill, insert, tap ect. Anyone have any clues. I've also got the same problem on one of my oil pan bolts. I'm so close to having her on the road, this is the last stumbling block.
Thanx
Ed Driscoll
PS
Do the threaded holes have a specific name? Hey, I'm a drummer by proffession, so it's all new to me.

[Greg L.]

Re: Stripped intake manifold, C3 SB

Hi Ed, What you are looking for is called a Heli-Coil. Most of the auto parts stores should be able to help you out. If they can't,then try the Yellow Pages under fasteners.

[Clem Z.]

Re: Stripped intake manifold, C3 SB

unless the manifold and the pan bolt are the same size and these kit are not cheap it may pay you to take it to a shop to have it done. JMHO

[William C.]

Re: Stripped intake manifold, C3 SB

About $10 per hole at my local parts store, Kits sell on eBay regularly for $10-20 per size. Search "Helicoil"

[Clem Z.]

Re: Stripped intake manifold, C3 SB

i have not bought any for quite a while but for a tap,inserter,drill and inserts i paid a lot more than $10/20 for the kit.

[Craig S.]

Re: Stripped intake manifold, C3 SB

It varies dramatically by size....the .25" down may be in the $12 range, but the big ones get up in the $30 range real fast. You can get them at McMaster-Carr....see website below...Craig




McMaster-Carr

[Craig S.]

McMaster-Carr - search on threaded inserts *NM*

[Pat Bush]

Re: Stripped intake manifold, C3 SB

Ed -

I am a keyboard player :-) but do a lot of machine work too. The guys are right on here. What you need is a heli-coil installed. Heli-coil installation is not hard, but if you haven't done it before and are not terribly mechanically inclined, you might want to have a machine shop do it for you. You will have to take the intake off but this is not hard at all.

The kits run 20-40.00 these days depending on what you need. I think 5/16-STD is the original thread on a small block if my memory serves me correctly.

If you do it yourself, you MUST drill the oversize hole 90 degrees to the manifold and the oversize tap MUST be started straight. Otherwise, the bolt will be crooked and not seal the carb correctly. If you mess up, the manifold will be a good candidate for a boat anchor.

Regards -

Pat

[Clem Z.]

PS

in drilling CI or aluminum if you already have a hole you must use a drill bit with a negative lip angle on the tip so it does not grab. it is no fun to have the hand drill spin around and smack you in the face. even in a drill press you need the negative lip angle.

[Ed Driscoll]

Re: Stripped intake manifold, C3 SB

Hi Guys,
Thanx for the input. My question was where do I find the products, not what to do. There are 2 brands of inserts that I know of, Helicoil and Keene sert. I was trying to get a bead on a local distributor as it's hard to find either of the kits, other then mail order. Anyway, all is well, found the kits, did the manifold and 2 bad oil pan holes. Smooth as silk. Thanx for all the help, particularly my friends @ Steiner Brothers in LIC. I'm about a week from resurrection and it's feeling good.
Cheers
Ed