angular torque being done wrong/ not done

["Dan, Marilyn, Anathea & Phillip Patzer" <bmrfamly@xxxxxxxxxx>]

Gentlemen
  Three times in the last three weeks, I've removed cylinder heads with new
head gaskets that were only torqued to 30-50 ft lb's of torque on M30
motors.  I always use a beam type torque wrench when removing heads so I
know how tight, or warped the head was.
  Two of the three motors were done by hobbyists, the third was on a "shop"
totally rebuilt motor including new oversize pistons.
  All of the failed headgaskets were the new style, which have a
recommended angular torque procedure.  One car had the head gasket set
package still in the trunk with the manufacturer's
instructions/specifications.
  The "spec sheet" was just specs, with no instructions.  It said, "58-64NM
15 min   36 deg   80 deg C   36 deg".
  This is a three step procedure, the first stage is normal tightening to
58-64NM (just an example as this varies with yr/model),  then the gasket
rests 15 min before tightening all bolts (install tightening sequence to be
observed) an additional 36 degrees of rotation regardless of required
applied torque.
  Next the engine is to be run at operating temperature of 80 deg
Centigrade (some applications indicate 10-20 minutes of running).  Then,
Hot or Cold (I prefer cold, the next day) all bolts are tightened an
additional 36 degrees rotation.  I always use a beam type torque wrench
above my angular torque gauge (fancy protractor) to see just how much
applied torque is require to achieve the desired angle.
  Much to my surprise, it often runs above 100 ft lb.
  It seems that too many motors are only receiving the initial 58-64nm of
torque and the "angular torque" follow-up is being completely left out.

 Dan Patzer the CyberWrench from BIMMERS ONLY Seattle's exclusive BMW hobby
shop
Providing O.E.M. parts, Independent service & Instruction since 1964
 12724  Marine Drive,  Marysville, Wa. 98271
72' tii touring   K1200LT   85' 732i   R850R
http://www.nwlink.com/~bmrfamly/   425-259-3601
MEMBER IBMWSP

------------------------------