Helicoil or Tap

[boardmonkey]

Hello,

I have read through the various tap and die posts and also the helicoil posts, but cant find the answer I want.

I had to remove the exhaust off my 1.9 wbx lump with all the usual complications of snapped bolts etc. Ive managed to get them all out bar one which snapped flush with the cylinder head. No option other than to drill out.

I have a tiny amount of the old thread still in the hole, and im toying with the idea of going up a size from M8 - M10 bolt for this one hole. Do I therefore drill a hole 8.5mm to prepare the hole and then tap it ? Or get the mechanic round to do it and fit a helicoil..at a cost of 85.00 plus Ill need to drop the engine out so he can get to it.

grrrrr. I have spent all weekend getting the lump back in the van after replacing cylinder head gaskets, and this was the last stage of re-fitting...

[jamesc76]

Do you have a set of taps ??? If so I would first try tapping it out to M8 again if not you wont have lost owt?

[boardmonkey]

Do you have a set of taps ??? If so I would first try tapping it out to M8 again if not you wont have lost owt?

good point. I knew there was a reason to post this question...cheers jimbo !

[SplendiferousII]

There is a place in threemilestone called fwb techfast that will seel you a "recoil" kit for about £20 maybe less not sure. Other places too, depends where you are.

A helicoil kit is the right way and easiest way to do the job.

call me on 07976 086 265 and i'll try to help you source the recoil kit locally.

but do it soon i am on the wine now.

[jdreamer]

helicoil it, worked well for me. I got a complete kit from Frosts (http://www.frost.co.uk" onclick="window.open(this.href);return false; search on "armacoil"). Kit comes with all you need - drill, tap & several inserts. Take your time and keep it all straight.

cheers, J

[Titus A Duxass]

As James stated, retap it to M8 first before doing a helicoil job.
It will probably work.

[boardmonkey]

As James stated, retap it to M8 first before doing a helicoil job.
It will probably work.

Ive still got some of the residue from the orignal bolt in there, will tapping it damage the tap or clean out the hole..?

[Ian Hulley]

I had some adaptor studs made which go from M10 back to M8 thus when the threads fubarred you can carefully retap to M10.

Ian.

[Titus A Duxass]

As James stated, retap it to M8 first before doing a helicoil job.
It will probably work.

Ive still got some of the residue from the orignal bolt in there, will tapping it damage the tap or clean out the hole..?

If you can pick out some or the residue it will help guide the tap in.
If you can't pick any out the tap will either cut a new path or force out the residue.

Ian's adaptors sound like a good back up if you have to go out to M10.

[Aidan]

i'd go for a timesert, but since you're not local to me you can't just pop round and borrow the kit and the kit is like £80 and you only get 5 inserts with the kit, but for this application, alloy head it's the best imho.

[boardmonkey]

Good news...

The tap worked a treat, happy days...engine now rebuilt, managed to fire it up as well ( albeit briefly)

Just received the very last replacement hose I was after, it was obsolete but tracked one down via Aidan and his German VW contact. It was the last one in Germany..!

Now all I got to do is fill Nellie up with water to test for leaks and then if ok refill with the VW coolant...one thing did dawn on me was what caused the van to overheat and blow in the first place...

Thanks for all your help and advice...

[Titus A Duxass]

Good news about the tap working.