Excess head bolt torque

[mattmey]

I am starting to think the directions on the head gasket I got are a little excess.

Is this typical?

Tighten to 45 lb ft
then 90 deg
then 90 deg again
heat cycle motor
90 deg again
1000 miles
90 deg again.

12 mm stock head bolts
whereas Haynes is 55 lb ft then 90 deg.

[steve]

I've done this procedure many times and haven't had a problem with doing it with NEW bolts.  It's a pain I know...  but I wouldn't do anything less.  I don't know where Haynes gets their info.  They are not the manufacturer of the engine, gasket, or the bolts... :?:

[tylernt]

Let's see...

Bentley:
30 ft-lb
44 ft-lb
one-half turn
heat cycle, quarter turn
1000mi, quarter turn

Haynes:
30 ft-lb
44 ft-lb
55-ft-lb
one-half turn
heat cycle, quarter turn
1000mi, quarter turn

Elring gasket:
30 ft-lb
44 ft-lb
quarter turn
quarter turn
heat cycle, quarter turn
621mi, quarter turn

So the Haynes has you do it tighter. Perhaps to reduce the risk of blowing the head gasket, but that also increases the risk of stripping the threads in your engine block!

Myself, I used the Elring instructions because it was easier for my puny muscles to make two quarter turns.  

[snootworks]

I just threw a 1.9L metal head gasket on my 1.6TD - Elring doesn't specify a re-torque after heat cycling...  which kind of makes sense, being a metal gasket.

Just curious what others have done with the metal gaskets?

[steve]

Here's what I'm guessing.  With TTY (torque to yield) bolts there is probably little chance of stripping anything because the max force is limited by the yielding of the bolt.  It eventually will have a problem if you keep turning.  The force will gradually increase due to work hardening of the bolt untill "snap" or "strip".  

But the extra angle achieved by going from 44 to 55 ftlbs is probably small and in the end comes out in the yielding of the bolt so the clamping force is probably not changed much.

All the instructions I've seen say that it's permissible to do two 90 degree turns in place of the single 180 degree turn.  That makes it WAY easier!!!

[935racer]

With metal hg's I do 30, 45, than 2 quarter turns and thats it.
With fiber hg's I do 30, 45, 2 quarter turns, than warm up the engine and do another quarter turn. I use headgasket sealant on all mine as well, Never had a problem with this setup ever.