Head Bolt Tightening On An Mi16

[Andy 105 1 Cars]

Technical query number two. What is the wisdom on the torquing of head bolts. ? The Peugeot method of 20nm + 300 degrees, the one suggested by Damir which progressively torques to 95nm or another method. Head face and block face have been machined and the block has only only had bolts torqued and removed once in its life ( by Peugeot) . New liners with a protrusion of 0.06 mm. Payen bolts

Andy

[petert 586]

I've always used 60Nm, slacken, 20Nm, then 300º.

[DamirGTI 342]

Which ever you prefer , i do them as i wrote for quite a while without any issues .. Final/total torque value ends up pretty much the same as when using OE method .

 

New bolts , clean bolt threads in the block , lube the bolt threads with MoS grease and it'll be fine .

 

D

[Andy 105 1 Cars]

Thank you both. Extremely helpful. I will take the lubrication advice ( rather than use engine oil) and proceed with the o.e system.

[DamirGTI 342]

Engine oil is fine , but grease is better .. with the engine oil , sometimes it tends to 'go dry' (threads binding , 'creaking') which increases friction within the threads and leads to the bolt clamping force/torque error on certain bolts while tightening them .

 

If you decided to go by OE torque spec. , can strongly advise to split the final 300 deg. sequence into three .. so three times 100 deg. for the final angle tightening rather than 300 deg. in one go .

 

Have fun !

 

D

Edited January 14, 2017 by DamirGTI

[Andy 105 1 Cars]

Hi. Thank you. Just to be clear. Do you mean take each bolt in turn and tighten in three, 100 degree increments or tighten all ten bolts by 100 degrees, then go back for the secon 100 etc?

Andy

[DamirGTI 342]

All the bolts from bolt No 1 till the bolt No 10 by 100 deg. in one stage , then move to the second stage ( again startng from the bolt No 1 till the No 10 ) + 100 deg. , and finally third last stage + 100 deg which will be 300 deg. total .

 

stage 1 - 60Nm

2 - slacken and tight back to 20 Nm

3 - 100 deg

4 - 100 deg

5 - 100 deg

..

[Andy 105 1 Cars]

Thank you. That is what I thought. Actually that regime seems like by far the most logical way as it is akin to torquing down to pre set torques in succession.

I am grateful to you for your help"

Andy

[Miles 331 1 Cars]

Having used a couple of brand new blocks the tightening is allot better than a old one by allot, I always tend to have a torque setting just as a point of reference when doing these and the older blocks vary but touch wood never had a issue with either