[Amc-list] Torqueing head - bar torque wrench okay?

[Nick ALFANO <71amx@xxxxxxxxxxxxx>]

Bruce,
 
My assumption is by your post that the engine is in the car and it is either an engine with some miles on it or one that has been sitting for a while and you are thinking of re-torquing the head bolts.  If it is a fresh engine, then the type of head gasket that was used will depend on whether a re-torque procedure is necessary or not.  If you just want to do it to be sure, the procedure you listed is correct.  If it is a running engine that didn't have a head gasket issue or a reason for you to think this is needed, then sometimes it is best to leave well enough alone.
 
As for the bar type torque wrench, no problem as long as you are confident it is still within a reasonable variance from spec.  Like any tool for measuring, it needs to be calibrated from time to time. A 1-3 lbs + or - is fine for a head bolt as the range is fairly wide.  Just shoot for the middle.  If it is off by 5 or more lbs, well that can start to be a problem especially since you may or may not know what type of lube if any is coating the head bolts.  Friction across the threads can make a dramatic difference in the amount of force needed to stretch the bolt properly to obtain proper clamping force especially if the torque wrench is off by that much.
 
If this is a V8, you will need to take the rockers off as well as you won't be able to get at some of the head bolts with them in the way.  Like anything else, proper care in doing the task right will go a long way.
 
Nick, 
 
Alfano Performance
4849-76 st.
Kenosha, WI. 53142
262-308-1302
262-942-8271 after 6pm central and weekends 
 
Message: 12
Date: Thu, 27 Mar 2008 09:58:57 -0400
From: "Bruce Griffis" <bruce.griffis@xxxxxxxxx>
Subject: [Amc-list] Torqueing head - bar torque wrench okay?
To: "AMC/Rambler owners, drivers and fans." <amc-list@xxxxxxxxxxxx>
Message-ID:
    <a72582d20803270658w6c2ef91eif0c6ca16cb248dae@xxxxxxxxxxxxxx>
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With the water pump and harmonic balancer done, I want to take a
little time and torque the head. I have the TSM and the sequence and
the specs. I think it shouldn't be that bad - and I figure I should
torque it before installing the valve cover gasket anyway.

So - bring it up to running temp (if I read right)
Follow the sequence in the TSM
  (anyone have it in PDF so I could print it and put a copy on the
fender? If not, I'll just copy
    from the TSM)
Torque to specs in the TSM
Question is - are bar torque wrenches accurate enough? Mine is a
little, ahem, old (a Craftsman from when I messed with a Karmann Ghia
about 25 years ago). Are dial torque wrenches more accurate?
Also, when torqueing - you back off the bolt a little bit first, then
torque it, right?
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