Stripped head bolt threads...

[Rusrog]

I am putting head gaskets on a GT-150 Johnson and have discovered that someone stripped the threads for one of the head bolts. No problem... Heli-Coil. Have done several with no problem in the past. This one is pretty tore up but it should work..... Nope. When torquing the heads down the Heli-coil pulled out at just under 20#'s of torque. Now I got a big nasty hoile that won't hold nothing.... Anybody had to deal with this before? Does someone make a bigger insert than a Heli-Coil???

HELP!

THANKS!

Russ Rogers
Ft Worth TX.
valeroruss@yahoo.com

[Jay Smith]

Hey Russ ,
You can use a product call a Keen Coil ( I think thats the name of it ) it works like a helicoil but better... BUT If that hole is bad enough you will have to make and incert to screw into the mother metal and then the bolt size will be tapped into the ID of the incert. The problem with most helicoils is that they are not long enough to bite into the alum. blocks to take that torque ratings heads need. Most are only 1/2" to 3/4" long . I order special lenths and you can get them 1 1/2" long and they will hold ....

Call me tomorrow after I get up from GRAVEYARDS ( 10:30 ish ) and I get you the name of that product !

[Rusrog]

around 10:30 or 11:00. Thanks!

Talk to you soon!

Russ

[Gordie Miller]

You can always stack 2 helicoils together, little ingenuity, but it can be done. Measure the depth of the hole and cut accordingly.

[BRENT GILL]

Get some one that welds alum. They will not be able to get real deep in the hole , but then you can redrill to get the proper fit that will hold the heli coil just fine.

[mardyn]

Russ, for a quick & cheap fix, try enlarging the bolt and hole/threads to the next size...ie: 5/16 up to 3/8".... those old dinosaurs like that one you're working on don't have to look good... but they do have to seal up...

DAB

[DaveR]

Give me a bit of time this morning. There are two company's that make I.D. / O.D threaded sleeves. They require a larger hole than the heli-coil and should work great. The drill hole for the sleeve is larger than than max thread dia for the helicoil so when you drill the hole, it completely cleans out all the heli-coil damaged threads.

I'll post the page.

[DaveR]

Try these inserts. I found them in J&L Industrial Supply, but any good tool supply house should be able to get them. Notice they come in carbon and stainless steel.

[Superdave]

These are Keenserts.
Keenserts (http://www.newmantools.com/kee.htm)
Machine shops have them or a bolt & screw co
DAve

[Talon2.5]

in the past i had step studs made out of stainless that eliminated having any helicoil deal at all

[Rickracer]

....can ship them tomorrow. how many do you need?:cool: