Re: Head bolt re-torquing

[Tpcutter@xxxxxxx]

In a message dated 4/8/05 10:08:22 AM Eastern  Standard Time, 
dr.ben@xxxxxxxxx writes:
<<On previous boxers,  conscientious attentions to the head bolts and cylinder
studs were important.  Not so on the Oilheads where after the 600 mile check,
nothing but neglect to  the whole dozen of them - except for loosening two
studs for valve sideplay  adjustment.

I'd appreciate any information on re-torquing or the  avoidance of same. It
seems there's a 90 plus 90 degree spec on the cylinder  studs (must make them
pretty tight, eh?). Is that the way to do it or could a  max torque rating be
used?>>

BMW claims that "angle  torquing," i.e. setting a minimal torque figure then 
turning the fastener a  specified number of degrees to achieve final clamping 
force, is more accurate  than conventional torque measurement devices when 
applied tot stretch hardware  incorporated in the Oilhead design. The same type 
of fasteners have been in use  in BMW cars since the early 80's, and on the K 
models since inception. It works  and is pretty easy to accomplish on the 
oilheads. 

I  retorque one additional time at around 10K miles, as that seems to 
alleviate  lots of cylinder head weepage complaints. Since the damn head gaskets are 
almost  $50 US, I always try a retorque before tearing everything  apart.

I actually just do the first initial torque of  14 ft/lb, then I go a full 
180 degrees in one shot. Haven't busted a stud or  torn out a case thread yet, 
although I have heard of both things  happening.



Tom Cutter
Yardley, PA
"The adventure begins  when things stop going as planned."
Rubber Chicken Racing Garage T-shirts  coming, inquire here...  

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