oops

[jed the spread]

I had two calls at work today ( from Asia ) offering me a "strategic marketing alliance opportunity"

Bet it was google adds cunningly disguised

jed

[jebiga41]

As I suspected stripped threads on the engine block engine is currently supported by a rachet strap around the sump and a bit of 4x4 across the engine bay, off to buy some helicoils

[silverbullet]

Make sure the coils aren't too long and don't forget to punch the tang off when they're in (or it WILL lock the bolt)
1/2 a turn under flush, at the risk of telling granny how to suck eggs etc...

[jebiga41]

All advice much appreciated, never used hellicoils before. Coils have 7 threads on them take it that's ok?

[silverbullet]

Did the kit say what inserts were included? They usually supply 1 x Diameter, but 1.5 x diameter is considered the maximum pull-out strength for the depth of hole.
In other words, there's no point going longer/deeper as they won't be any stronger in tension. Longer inserts are usually specified for wear resistance in parts that frequently get dismantled or other special conditions, like when the bolts are in shear or side loaded (more area to spread the load)
7 turns for M10 x 1.5 (working from memory...) would be 1 x Diameter. longer might be better - how deep is the hole in the block?

[jebiga41]

Not sure but coils came in a multiset so all standard I would assume. Will try and measure the depth 2moro is it possible to double coil them? i.e. Put one in deep and another one on top giving more threads and acting like a long coil?

[silverbullet]

is it possible to double coil them? i.e. Put one in deep and another one on top giving more threads and acting like a long coil?

No no no no no!

The bolt will either:
1. Run through the first coil and hit the second and not pull down
2. The bolt will go in, the two coils will lock against each other when you want to remove the bolt and you'll be back to drilling it out with no second chance
3. A grim combination of both. Bolt ratcheting in the hole, not pulled down and unable to back out

Get the correct coils, then start.

PS. They should be 0.5 to 1 diameter off the bottom of the hole anyway, to allow for the run-out of the thread and removing the tang.

[Aidan]

I've got an M10 Timesert kit here, never used, got it when my engine bolts snapped in case I had to do the block but it was cos they'd used mild steel bolts and case threads hadn't pulled; prefer these to helicoils personally, great in alloy cases

[silverbullet]

Timeserts? The ones with the drive-in locking wedges?
They're great for recovering a badly damaged/oversize hole

[jebiga41]

up date on my engine, as it turned out had sheared one of the bolts


came out easy enough and replaced all the bolts with these 12.9's cut to size with washers to get the distance

heli-coiled the other holes and thread locked everything so should be ok




prior to this had been resting on the engine protection

and then supported by a ratchet strap and a piece of 4x4