No need to torque head (or any other stud). Just make sure that everything
is clean, and run down finger tight, perhaps with a small 'nip' on them to
help keep them in place when the head is removed again.
reason is this -
When winding in a stud it stops turning for one (or both) of two reasons.
The stud has reached the bottom of the hole, or the stud has run out of
thread (sometimes both happens)
(1) Stud at bottom of hole. Applying torque in this situation will wind the
stud down against the bottom of the hole and load threads in the block in an
upwards direction. When the head is in place, and the head nuts are torqued
down, the tension force in the stud is resisted by the threads in the block.
This force is in ADDITION to the force already present because the stud is
bottomed out. Result is that the threads in the block are loaded to twice
the required load .
(2) Thread bottoms out. Applying torque in this situation is only going to
wind the stud in further, damaging the thread in the block , and scoring the
unthreaded part of the stud until enough resistance is generated to match
the torque that you are attempting to apply. This results in damaged
threads in the block, damaged studs, and again an upwards force in what
remains of the thread in the block. Tourquing down the head will transfer
the load from the section of stud previously jammed against the damaged
treads at the top of the hole, There is no actual increase in upward load on
the threads in the hole, but they are less sound, and the stud is damaged.
Ian F
If
-----Original Message-----
From: Dave Wood <djw69@idt.net>
To: MGB <mgs@autox.team.net>
Date: Monday, March 20, 2000 5:16 PM
Subject: Re: Head Studs
>I don't recall ever seeing a torque setting for studs, but I have always
>cleaned the threads and put them in tight. If you use a double nut to put
>them in you can tighten to approximately the same as the nuts, which is 45
>to 50 lb. ft. I would do a bit less say 35 to 40 myself. If you use a
stud
>remover just make them reasonably tight. If you go past the ends of the
>threads, you will likely break the stud. The important thing is the head
>bolts and the order that they are tightened. Start at 10-15 lbs for all,
>then increase by 10 lbs or so in the correct order. If you don't know the
>order, start in the middle of the head and work your way left and right up
>and down towards the ends to distribute the tension evenly. Then start
over
>in the middle increasing the torque by about 10 lbs and do it again and
>again until all the nuts are 45 to 50 ft lbs. You will find that the studs
>are tightened at the same time that the nuts are tightened, so you don't
>have to worry too much about putting the studs in, except to make sure you
>have enough threads in that they won't pull out. One more thing, remember
>to retorque after running the engine and getting it warmed up.
>
>Hope this helps. I never had a problem with a B, but sure have lots of
>experience with old flat head Fords and Mercs from years ago.
>
>Dave 72 B
>-----Original Message-----
>From: ahhclem@kcnet.com <ahhclem@kcnet.com>
>To: mgs@autox.team.net <mgs@autox.team.net>
>Date: Sunday, March 19, 2000 7:21 PM
>Subject: Head Studs
>
>
>>Does anyone know if there is a torque value for the cylinder head studs?
>>I've looked thru the Haynes book and don't see a reference.
>>
>>
>
>
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