Head bolt snapped

[snowy]

I would just like to let people know that it is worth changing the four M8 head bolts around the timing chain, not just the main head bolts alone when doing a cylinder head.

I re used the original four and one snapped during installation.

Just to point out a few things;

1. I know the history of the car and I know the head has never been off before.
2. I did run a tap down the threads in the block and clean the holes out with compressed air
3. I did use a torque wrench to tighten them up. I am also in a good position of being able to check the calibration of my torque wrenches in work.

I know this might be rare but for the sake of a set of four bolts I recommend buying them.

I was lucky as it snapped pretty much under the head of the bolt. So when I took the head back off I was able to fit two nuts and unscrew it out.

I hope this helps someone else as if it had snapped flush with the block it would have made life more difficult.

 

[pottsey]

im glad i bought new ones then ,cuz if things can be snapped or broke i will manage to do it lol
i bought this set for anyone else looking
http://www.ebay.co.uk/itm/170938137330?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

 

[evocarlos]

good to know

 

[vocky]

I usually use a little ARP grease on the bolt heads to stop 'pick up' which causes the head to shear off

 

[snowy]

The head didn't shear off, but only a thread or so underneath.

I would have greased under the head but none of the guides or manuals I have read recommended it.

Thanks for the suggestion.

 

[vocky]

I found that even the larger head bolts can 'pick up', so normally I add some grease or oil whenever I fit them.