helicoil thread repair?

[sorrento205]

Hi guys, ive got a stripped headbolt thread i need to repair but im not sure what helicoil kit i need to use.

The bolt is M10 (approx 13/32"), with 18 threads per inch. I dont know how to identify wether this is fine,medium or coarse.

Any help greatly appreciated :)

[GreenV8S]

If its 17 tpi that would correspond to 1.5mm thread pitch, M10x1.5 is metric standard thread (10mm metric fine is M10x1.25).

[v8 racing]

what engine is it for?

[Trooper2]

Is a Helicoil repair strong enough for stipped out head bolt threads in a block?

I Know for big Diesels they make a special threaded sleeve so you don't end up with a coolant leak and because Helicoils simply pull out.

[GreenV8S]

Speaking of which, anyone know what thread the holes are on the end of the RV8 cylinder head? They're the ones that are used to attach engine lifting brackets etc. Except that mine have been 'borrowed' somewhere along the way and I'm struggling to match with any metric or UNF threads.

[v8 racing]

a helicoil would be strong enough for most petrol engines but i would use a timesert myself much stronger

[v8 racing]

almost right andy!! the lifting eyes are 3/8 unc same as exhaust manifolds, the smaller ones are the 5/16 unc

[sorrento205]

GreenV8S said:

If its 17 tpi that would correspond to 1.5mm thread pitch, M10x1.5 is metric standard thread (10mm metric fine is M10x1.25).

could be 17, maybe i miscounted

its for a peugeot 1.9 Mi16 block but only an 8v head being fitted.

cheers for posts guys

[steve_D]

I have used Helicoils on 3 head bolts on my Chevy V8.
It now makes 508hp so I think they must be strong enough.

Steve

[sorrento205]

another quick Q, will it matter that the inserts are stainless steel (the Mi16 block is alloy).

the metals will expand and contract at different rates, plus over time could lead to dissimilar metal corrosion?

maybe thats being too picky i'm not sure

[steve_D]

Where I work we would use a product called DURALAC on the insert and the bolt for the dissimilar metal corrosion problem. In your case I would not worry to much. Putting the insert in with Loctite might help.

Steve

[base-1]

sorrento205 said:

GreenV8S said: If its 17 tpi that would correspond to 1.5mm thread pitch, M10x1.5 is metric standard thread (10mm metric fine is M10x1.25). could be 17, maybe i miscounted its for a peugeot 1.9 Mi16 block but only an 8v head being fitted. cheers for posts guys

from memory it is just std M10, if i had measuring stuff here id go downstairs and whip the head off my other Mi to see for you, blocks are same as 8v only bottom end parts are different