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View Full Version : Wedge proper torque for TR7 cylinder head



srmorse
10-06-2003, 05:57 PM
There are conflicting numbers between the Haynes and BL manual. One says 50 lbs...the other 55. I've also seen quite different numbers on various boards, club sites, etc.

Any ideas what the actual number should be? images/icons/confused.gif

Mark Beiser
10-06-2003, 06:31 PM
My Haynes manual and my "The Complete Official Triumph TR7" book both list it as 50 lbs.

tr7sprint
10-07-2003, 12:21 AM
Mark B.is right,i just look this up in my triumph technical service bulletins.
the tech service bulletin came out in 79 revising the torque from 55lbs/ft to 50lbs/ft.

also in this tech bulletin it also revised the head tightening sequence.

Cliff Davis
78 fhc soon to have sprint motor conversion.
79 fhc

srmorse
10-07-2003, 12:54 PM
Thank you for all the help so far...

What is the revised tightening sequence? Anyone have a link I can check?

Knowing how finicky the heads are on our cars I just want to be sure I get it right!!!

MichaelF
10-08-2003, 02:25 AM
I'm intersted in this too -- though after the fact. I installed my head in the spring @ 55 lbs.

Haynes, I recall, suggested the familiar criss-cross tightening sequence you see on most heads that bolt down directly. Other manuals had 3 cycles 20 -> 35 -> 55 lbs doing *first* the studs along the 'top' side nearest the inlet manifold and then the 'bottom' bolts along the exhaust manifold side.

In the end I concluded that the Haynes authors had been in a hurry and simply copied an old method used on most other cars. I went with the seemingly odd method suggested in the BL manual on the ground that it made perverse sense of how best to tighten those slanted fastners.

So far so good ....

Dale
10-08-2003, 10:46 AM
Started at 55 lbs on mine and increased it at each retorqueing 'til I was certain it had seated and sealed. Now at 70 lbs and doing well. Have heard of others at 80 plus lbs. Don't try this without the good ARP bolts and studs though. I know you guys are going to jump me for this and I deserve whatever dirision you direct, but it's the truth and I'll swear to it. graemlins/crazy.gif

ktemkin
10-08-2003, 06:18 PM
Dale,

Why not 250 ft-lbs., if it might take it?

There are many good reasons why torque values are set at particular levels.

Is your experimentation based upon some kind of analysis, or are you just followingf the axiom that "bigger must be better?"

Ken

tr7sprint
10-08-2003, 06:46 PM
is there an place on this site to post the tech bulletin, so all can see.

otherwise, i'll send it to person who directed the question.

ObiRichKanobi
10-08-2003, 09:49 PM
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr> is there an place on this site to post the tech bulletin, so all can see <hr></blockquote>

Under the links button, there's a tech tips. I'm not sure that it supports graphics tho....