[AT] Torque for bolts vrs studs in cylinder heads?--followup

[Larry D Goss]

If I remember correctly, the instructions for one of those engines reads 
something like: Torque to XX ft-lbs and then turn the bolt 180 degrees more. 
It's the only type of engine that ever caused me to work up a sweat while 
torquing head bolts even while working outside on a cold day.

Larry

----- Original Message ----- 
From: "charlie hill" <chill8 at suddenlink.net>
To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>
Sent: Saturday, April 28, 2007 12:32 PM
Subject: Re: [AT] Torque for bolts vrs studs in cylinder heads?--followup


> John,  some of the new light weight auto engines use head bolts that are
> "torque to yield"  which means they are tightened to where they are just 
> at
> the point of failure.   When you remove the heads on those engines you 
> MUST
> replace the head bolts.  Those first GM diesel car engines (the 5.7 built
> from a gasoline block) were that way.
>
> In other words they used the smallest, lightest head bolts they could get 
> by
> with and they won't stand up to being re-used.
>
> Charlie
>
>
> ----- Original Message ----- 
> From: "John Wilkens" <jwilkens at eoni.com>
> To: "Antique tractor email discussion group" 
> <at at lists.antique-tractor.com>
> Sent: Saturday, April 28, 2007 1:22 PM
> Subject: Re: [AT] Torque for bolts vrs studs in cylinder heads?--followup
>
>
>> Many thanks guys for educating me about head bolts!   To be sure,
>> I'll stick with studs!    John W.
>>
>>
>>
>> At 08:08 PM 04/27/2007, you wrote:
>>>
>>>John, There are a whole bunch of GOOD reasons to stay with all of the OEM
>>>parts and torque specs on head bolts! You may get away with some
>>>non-OEM parts
>>>sometimes but it is like gambling with your engine's life span. Granted 
>>>it
>>>varies from engine to engine, usually older engines have more room
>>>to play with
>>>and more modern engines have tighter specs with almost no room for error.
>>>Some  head bolts are TTY and can only be used once. The headgasket
>>>thickness also
>>>  matters on some engines especially if you have had the head resurfaced.
>>>Sometimes the OEM manual will give 2 torque specs with the head bolt
>>>dry or oil
>>>on threads. Studs or bolts of the same grade should be the same spec I
>>>think.
>>>If  you lower the grade of bolt you may be asking for problems. Just my 2
>>>cents.  Willard Smith, Tacoma, WA.
>>>
>>>About how much more torque would be required for using bolts in an
>>>engine head vrs. the regular studs?  (One for the  experts!)   John W.
>>>
>>>In the wide-open spaces of NE  Oregon
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>************************************** See what's free at
>>>http://www.aol.com.
>>>
>>>_______________________________________________
>>>AT mailing list
>>>http://www.antique-tractor.com/mailman/listinfo/at
>>
>>
>>                    In the wide-open spaces of NE Oregon
>>
>>
>>
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