Author Topic: Stripped threads in block- best option? (Read 3091 times)

Vanagoner · « **on:** May 31, 2008, 05:38:17 pm »

Head gasket job, '81 1.6 mechanical n/a, old non-stretch bolts, corner one stripped at 70 ft/lbs.
What is the best thing to do at this point- can a helicoil even be bought for this size? Would a stud kit work in it the way it is?

Possum79 · « **Reply #1 on:** May 31, 2008, 07:21:09 pm »

I can't remeber who said it but a stud kit will grab a lot more threads then the bolts do. It goes much deeper then the head bolt does so it should work. Unless its totally toast.

or drill/tap to 12mm?

subsonic · « **Reply #2 on:** May 31, 2008, 07:59:22 pm »

I vote for tapping it to 12mm and buying 1 12mm head bolt. Problem solved. Was the 70lbs of torque the part with the "additional half turn"?

fatmobile · « **Reply #3 on:** May 31, 2008, 11:18:54 pm »

I'd say 11mm stripped out hole will have 1/2mm on each side of the bolt for threads if you are planning to tap it to 12mm.
Are 1/2mm deep threads enough?
Looking at my trusty ruler, I'd say ,"No".

Vanagoner · « **Reply #4 on:** June 01, 2008, 08:15:33 am »

No subsonic, I was on my way up to 90 with all of them. All I have at this point is a Haynes manual and I couldn't find the torque spec in there.
I would try 1 12mm bolt to get me by, but after buying a tap of whatever size that is I'd be partway to a stud kit, which would be better overall.

subsonic · « **Reply #5 on:** June 01, 2008, 01:51:48 pm »

The spec for 12mm bolts on my 1.6na is 44pounds plus a 180 degree additional turn on each.

gldgti · « **Reply #6 on:** June 01, 2008, 02:14:16 pm »

you can get helicoils that big easy, and they work perfectly well. helicoils are actually often better performing than original.

RabbitJockey · « **Reply #7 on:** June 01, 2008, 02:22:28 pm »

it could already be an 11mm motor, my old 81 had 12 mm head bolts and a 19mm crank bolt

Turbinepowered · « **Reply #8 on:** June 01, 2008, 05:34:34 pm »

Spec for 11mm bolts (1.5) is 65 ft-lbs as per Bentley.

Vanagoner · « **Reply #9 on:** June 01, 2008, 07:44:47 pm »

:oops: as the old saying goes, if you think education (a bentley manual) is expensive, try ignorance. :oops:
thanks guys- I'll helicoil it, and go shopping for a proper manual

fatmobile · « **Reply #10 on:** June 01, 2008, 11:19:04 pm »

There was a post about this, over on vwdieselparts.com.
Someone suggested there is something better than helicoil,... something that goes farther into the block.
Helicoils are short and can put too much pressure in a small area.... stripping it out or cracking the block.