Mustardxf 29 Posted July 30, 2015 Hey guys, Stripped a thread in the head(intake manifold side) brought a helicoil and when I was tapping the thread it got half way and started going of centre. Now the hole is not straight, bolt goes in only so far. Options I have thought about:Run with no bolt.screw the bolt in as much as I can and use washers to fill the gap.OR I have a bigger heli coil kit here, so i could re-drill it and tap it for a larger thread.Any ideas? Share this post Link to post Share on other sites
gromet88 3,042 Posted July 30, 2015 i'd prob go with the short bolt idea as temp fix then maybe down the track, re-seat the hole completely when there is a time of taking head off 1 xSMOKEx reacted to this Share this post Link to post Share on other sites
xSMOKEx 47 Posted July 31, 2015 yeah i have done this before my self , made me so mad to , just use a shorter bolt with a washer for now , do a proper fix later one day when you got the head off , bad idea to try and drill it whilst its still in the car, it wont hurt it running a shorter bolt . 2 Mustardxf and slydog reacted to this Share this post Link to post Share on other sites
Mustardxf 29 Posted July 31, 2015 okay thanks for the help!I lost sleep over it last night and Im still yet to tell dad has he thinks that nothing went wrong. didn't help that there wasn't much light when I was doing it. Later on when I take it out do you suggest that I go up a bolt size and just re drill it? Share this post Link to post Share on other sites
gregaust 319 Posted July 31, 2015 You can get inserts for a bigger hole . Look up Threadsert or keensert Share this post Link to post Share on other sites
Jiminy Kriket 133 Posted July 31, 2015 With the intake threads, they are 5/16" UNC standard. When they strip they just happen to clean up to the tapping size for 3/8 UNC (same thread as the exhaust bolts), which is what i ended tapping 3 of those threads to after some dodgy mechanic had a go at my first crossy head. Drilled the hole in the manifold to 10mm and wound the 3/8 tap straight into the threaded hole and job done. Just be sure to get all the ally chips out of the rocker area. 1 gerg reacted to this Share this post Link to post Share on other sites