Helicoil Question

[Rom 0]

Ever since i bought my Mi engine, one of the cam cover bolt threads had been 'repaired'

 

Its been retapped from 6mm 1.0 to 8mm 1.25. It had a bit of threaded rod in, with a nut underneath the head. And another nut on after the cam cover goes on.

 

Ive got everything out of the car for the respray, and want to fix this, so i can use a proper bolt in it.

As far as i know from prvious use, helicoils need to be tapped with the proper thread for them, and dont seem to go from 6 to 8.

Ive has a search around, but not managed to find any helicoil etc that would do what i want ?

 

What other options do i have, short of welding and starting all over.

 

Chris

[Mad Professor 7]

I know meny pepole that have used Helicoil's before in the past, but me myself I don't like them.

 

I used something called Time-Sert

 

 

YouTube Clip:

 

It's not a cheap kit, but it's saved me alot of hassle in the past.

[Rom 0]

It seems no insert can go from 8mm to 6mm.

 

After speaking to local engineering place, it all made sense !

 

They will drill into the 8mm bolt, tap a 6mm thread. Then just loctite the 8mm in, and were good.

Maybe not the best solution. But beats having the head welded.

 

Chris

[Guest bigface]

Helicoils are actually a lot strong than a standard thread because they are made out off stainless steel. Ive work in engineering for 8 year and never had a proble with them as long as they are fitted properly. when ive had problems like yours in the past the best thing to do is make a alloy bush that is an M8 thread on the outside with a M6 in the inside then locktight it in.