Helicoil

Ronin · #1 21-09-2006, 12:05

A stud hole on my exhaust manifold has been helicoiled, badly as the oil gallery had been holed and it leaked oil and it never stayed tight. Today I noticed loads of smoke coming from under the bonnet had a look and and the stud was was hanging out with the helicoil on the stud. What I want to know is will it be possible to redo the helicoil and if so what thread do I need ect.

PukkaSilvia · #2 21-09-2006, 18:11

check the helecoil and see if it has pulled out ali with it. It probably has.In which case you will need to go up a size. You could either tap the whole thing to m12 and use an m12 bolt or m12 studding and nut(Another option is to go to an af thread like 3/8 unc) or you could go for an the next size up helecoil--

M 11 x 1.5 pitch

You should be able to get a stud or at least a bolt from a good fastenings company but inquire first before you get the kit.

I did tap mine to m12 on my old et engine and it worked but if you mess it up or that thread goes you will need a new head or your head welded.

You can helecoil in situe if you use a 90 degree chuck air drill.

Oil has come out that stud hole on a few s12s that have been helecoiled badly in the past by SE nissan. Put some silicon in the hole before you wind your new stud/bolt in and it will be fine

Helecoils can be found at

http://www.toolsnextday.ltd.uk/Helic...icoil_kits.htm

If your lucky and the helecoil just wound itself out you could reinsert a new one the same size.Somehow i doubt thats happend. Have a look

Ronin · #3 21-09-2006, 19:36

The helicoil was pulled right out, I'll try a M12 but I have a feeling the DET conversion is look to be on the cards at the moment.

Ronin · #4 22-09-2006, 13:28

Just been out and had a look and the hole is completly shagged my M12 tap slide straight in and out of the hole without touching the sides. So it looks like a new head or engine and at this point I'm leaning towards a new engine which I expect will be a DET when I can afford it as one of these is easier to find than an ET, So that's another S12 off the road for the fore seeable future, cleaning the soot from under the bonnet will keep me occupied for the time being though.