: How hard to try to pull the head bolts on Northstar?



aaberg
12-19-11, 05:03 AM
I have done the Time-sert on my 1998 STS Northstar-engine. Now installing heads. Regarding to the manual following process have to be done:

1. Tighten head bolts with 30 Nm
2. 60 degrees.
3. Another 60 degrees.
4. Finally last 60 degrees (total of 180 degrees in sequence).

After doing the 3 first steps the bolts are really tight and nearly impossible to pull the last 60 degrees. Is this normal and how hard to pull to get the last 60 degrees?

I checked with my torque wrench that now shows close to 70 Nm, if this can be compared since it is the bolts that are supposted to be stressed with the 180 degress.

ternstes
12-19-11, 10:50 AM
You need more leverage. Slip a pipe over your wrench or get a longer wrench.

aaberg
12-19-11, 12:34 PM
Thank you for answer. I tried to pull them to final 60 degrees and it worked. Was just to afraid to break anything.

stoveguyy
12-21-11, 02:21 PM
what do you think your final torque is?

aaberg
12-21-11, 03:21 PM
The first torque was 50 Nm and second 70 Nm, but didn't check the third and last one. Maybe logical it will be about 90 Nm (started at 30 Nm, first 60 degress was 50 Nm, second 70 Nm and third could be 90 Nm? Anyway seems possible the last torque can be around 90 Nm - perhaps someone out here can confirm if so?