Home » Public Forums » GMCnet » Loose head bolts
| Loose head bolts [message #106945] |
Sun, 28 November 2010 14:39  |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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As many of you may recall, I spent the summer redoing the head and manifold gaskets on my revcon.
I learned a lot and i did a lot of other stuff while I was in there, transmission lines, electric fans, etc.
It would all be great except in the end it leaked.
Only on one side.
Today I pulled the manifold and the right head.
The head bolts offered very little resistance. Of all the stupid things I may have done during this job, I'm certain I torqued all the bolts.
Should I have torqued them again? I got lots of advice form guys on this board, and I thought someone said NOT to torque the bolts again.
So what's the deal? Should I have tightend them again after it sat for a while? After it started the first time? After a few miles?
Thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
[Updated on: Sun, 28 November 2010 14:39] Report message to a moderator |
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| Re: [GMCnet] Loose head bolts [message #106947 is a reply to message #106945] |
Sun, 28 November 2010 15:16  |
larry churchwell
Messages: 9
Registered: June 2010
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did you used new bolts if you used old they maybe stretching and need
replacing
On Sun, Nov 28, 2010 at 3:39 PM, dave silva <david.j.silva@uscg.mil> wrote:
>
>
> As many of you may recall, I spent the summer redoing the head and manifold
> gaskets on my revcon.
>
> I learned a lot and i did a lot of other stuff while I was in there,
> transmission lines, electric fans, etc.
>
> It would all be great except in the end it leaked.
>
> Only on one side.
>
> Today I pulled the manifold and the right head.
>
> The head bolts offered very little resistance. Of all the stupid things I
> may have done during this job, I'm certain I torqued all the bolts.
>
> Should I have torqued them again? I got lots of advice form guys on this
> board, and I thought someone said NOT to torque the bolts again.
>
> So what's the deal? ShouldIhave tightend them again after it sat for a
> while? After it started the first time? After a few miles?
>
> Thanks
>
>
> --
> Dave & Ellen Silva
>
>
> Happy owners of a 1972 Flatnose Revcon
> Here by the generosity of the GMC community
> http://www.davesilva.com/revcon
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
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| Re: [GMCnet] Loose head bolts [message #106948 is a reply to message #106947] |
Sun, 28 November 2010 15:20 |
larry churchwell
Messages: 9
Registered: June 2010
Karma: 0
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Junior Member |
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the way to check after torquing set the t wrench for 1/2 of the torque and
loosen the bolts one at a time and if they come loose a 1/2 torque spec.
replace them
On Sun, Nov 28, 2010 at 4:16 PM, larry churchwell <churchwelllarry@gmail.com
> wrote:
> did you used new bolts if you used old they maybe stretching and need
> replacing
>
>
> On Sun, Nov 28, 2010 at 3:39 PM, dave silva <david.j.silva@uscg.mil>wrote:
>
>>
>>
>> As many of you may recall, I spent the summer redoing the head and
>> manifold gaskets on my revcon.
>>
>> I learned a lot and i did a lot of other stuff while I was in there,
>> transmission lines, electric fans, etc.
>>
>> It would all be great except in the end it leaked.
>>
>> Only on one side.
>>
>> Today I pulled the manifold and the right head.
>>
>> The head bolts offered very little resistance. Of all the stupid things I
>> may have done during this job, I'm certain I torqued all the bolts.
>>
>> Should I have torqued them again? I got lots of advice form guys on this
>> board, and I thought someone said NOT to torque the bolts again.
>>
>> So what's the deal? ShouldIhave tightend them again after it sat for a
>> while? After it started the first time? After a few miles?
>>
>> Thanks
>>
>>
>> --
>> Dave & Ellen Silva
>>
>>
>> Happy owners of a 1972 Flatnose Revcon
>> Here by the generosity of the GMC community
>> http://www.davesilva.com/revcon
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> List Information and Subscription Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
>
>
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| Re: [GMCnet] Loose head bolts [message #106951 is a reply to message #106948] |
Sun, 28 November 2010 15:59 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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You need to torque by the sequence that is called out in the book or
close to it and go around few times until it does not rotate at the
specified torque.
There is a chance you might have a warped head or a block that was milled wrong.
Head bolts on these engine have not stretched unless you go way over specs.
On Sun, Nov 28, 2010 at 1:20 PM, larry churchwell
<churchwelllarry@gmail.com> wrote:
> the way to check after torquing set the t wrench for 1/2 of the torque and
> loosen the bolts one at a time and if they come loose a 1/2 torque spec.
> replace them
>
> On Sun, Nov 28, 2010 at 4:16 PM, larry churchwell <churchwelllarry@gmail.com
>> wrote:
>
>> did you used new bolts if you used old they maybe stretching and need
>> replacing
>>
>>
>> On Sun, Nov 28, 2010 at 3:39 PM, dave silva <david.j.silva@uscg.mil>wrote:
>>
>>>
>>>
>>> As many of you may recall, I spent the summer redoing the head and
>>> manifold gaskets on my revcon.
>>>
>>> I learned a lot and i did a lot of other stuff while I was in there,
>>> transmission lines, electric fans, etc.
>>>
>>> It would all be great except in the end it leaked.
>>>
>>> Only on one side.
>>>
>>> Today I pulled the manifold and the right head.
>>>
>>> The head bolts offered very little resistance. Of all the stupid things I
>>> may have done during this job, I'm certain I torqued all the bolts.
>>>
>>> Should I have torqued them again? I got lots of advice form guys on this
>>> board, and I thought someone said NOT to torque the bolts again.
>>>
>>> So what's the deal? ShouldIhave tightend them again after it sat for a
>>> while? After it started the first time? After a few miles?
>>>
>>> Thanks
>>>
>>>
>>> --
>>> Dave & Ellen Silva
>>>
>>>
>>> Happy owners of a 1972 Flatnose Revcon
>>> Here by the generosity of the GMC community
>>> http://www.davesilva.com/revcon
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> List Information and Subscription Options:
>>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>>
>>
>>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Loose head bolts [message #106953 is a reply to message #106951] |
Sun, 28 November 2010 16:22 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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| jimk wrote on Sun, 28 November 2010 15:59 |
You need to torque by the sequence that is called out in the book or
close to it and go around few times until it does not rotate at the
specified torque.
|
I think I was pretty careful with the sequence. But alas, the bolts do appear stretched according to the simple test described on this web site:
http://www.zparts.com/zptech/tech_tips/kbtt/pages/tech_tip2b.html
Any recomended vendor?
Gven that the leak was clearly visible near where I had one of the loose bolts, and given the pristine appearance of the head (only 25,000 miles) I feel pretty good about the diagnosis.
But I'll look closely at the head surface before Idothis again.
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: [GMCnet] Loose head bolts [message #106955 is a reply to message #106953] |
Sun, 28 November 2010 16:53 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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You might want to take a careful look at the block and head for possible crack.
When it comes to assembling the engine, I spend lot of personal time
that I do not charge the customer for and double check
Make sure the torque wrench is calibrated in pounds per feet and not metric.
I did out company truck engine one time and over torqued it , but
caught the mistake in time to correct.
You might want to let it sit for an hour and then go back and re
torque it carefully again.
Make sure the bolts have a very light coat of sealer to avoid a wrong
feel that it has reached the max torque.
Never jerk on the torque wrench, just slow and easy force.
There are some spray sealer that one can use on the gasket to augment the seal.
On Sun, Nov 28, 2010 at 2:22 PM, dave silva <david.j.silva@uscg.mil> wrote:
>
>
> jimk wrote on Sun, 28 November 2010 15:59
>> You need to torque by the sequence that is called out in the book or
>> close to it and go around few times until it does not rotate at the
>> specified torque.
>
>
>
> I think I was pretty careful with the sequence. But alas, the bolts do appear stretched according to the simple test described on this web site:
>
> http://www.zparts.com/zptech/tech_tips/kbtt/pages/tech_tip2b.html
>
> Any recomended vendor?
>
> Gven that the leak was clearly visible near where I had one of the loose bolts, and given the pristine appearance of the head (only 25,000 miles) I feel pretty good about the diagnosis.
>
> But I'll look closely at the head surface before Idothis again.
>
> thanks
> --
> Dave & Ellen Silva
>
>
> Happy owners of a 1972 Flatnose Revcon
> Here by the generosity of the GMC community
> http://www.davesilva.com/revcon
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Loose head bolts [message #106957 is a reply to message #106945] |
Sun, 28 November 2010 18:30 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Dave, the only case where you would not retorque the heads is when you use
the "permatorque" blue head gaskets. They specifically instruct you to not
retorque. Any other gasket used, this is the method that I personally use
and have done many Olds engines with good results. I always wire brush the
head bolts and very carefully inspect them. If there is any narrowing or
signifigant rust, I replace them. I always chase the threaded holes with the
appropriate sized tap and very carefully inspect the block for any signs of
cracking. It goes without saying that all metal & crud in the holes needs to
be blown out with compressed air. If the hole is open to the water jacket,
then a non hardening sealer such as permatex is used. If the holes are
blind, then just spray them with wd-40 or similar product. If the torque
spec calls for 60 ft#, I start with 40, go through the proper sequence, then
to 50, and finally to 60 ft#. After I start the engine for the first time
and do the cam & lifter break in, I let the engine set overnight so that it
is room temperature & then re torque to spec. If anything feels strange when
retorquing, now is the time to investigate, particularly anything that is
loose. I forgot to mention that I always run in a new rebuild on an engine
stand before installation. If there is any problems that arise, it is a
whole lot easier to fix when the engine is out, You will no doubt have
others tell you somewhat different proceedures & I have no problem with
other methods if they are successful. This method was taught to me in GM
School, and I use it with great success. I would never, ever, use air impact
tools to assemble an engine. You need to feel the threads going together, if
they are too tight, stop & find out why.
Jim Hupy
Salem, Or
78 Royale 403
On Sun, Nov 28, 2010 at 12:39 PM, dave silva <david.j.silva@uscg.mil> wrote:
>
>
> As many of you may recall, I spent the summer redoing the head and manifold
> gaskets on my revcon.
>
> I learned a lot and i did a lot of other stuff while I was in there,
> transmission lines, electric fans, etc.
>
> It would all be great except in the end it leaked.
>
> Only on one side.
>
> Today I pulled the manifold and the right head.
>
> The head bolts offered very little resistance. Of all the stupid things I
> may have done during this job, I'm certain I torqued all the bolts.
>
> Should I have torqued them again? I got lots of advice form guys on this
> board, and I thought someone said NOT to torque the bolts again.
>
> So what's the deal? ShouldIhave tightend them again after it sat for a
> while? After it started the first time? After a few miles?
>
> Thanks
>
>
> --
> Dave & Ellen Silva
>
>
> Happy owners of a 1972 Flatnose Revcon
> Here by the generosity of the GMC community
> http://www.davesilva.com/revcon
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] Loose head bolts [message #106958 is a reply to message #106953] |
Sun, 28 November 2010 18:35 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Dave,
ARP - see eBay item 330495712910.
My way of torquing stuff is:
Lubricate fasteners with lightly with oil.
1) set the wrench at 1/2 the torque setting
2) torque fasteners
3) set the wrench to 3/4 the torque setting
4) torque fasteners
5) set the wrench to the full torque setting
6) torque fasteners
7) wait a couple of hours and torque at full setting again and note if any
fastener rotates
8) wait 24 hours and torque at full setting and note if any fastener rotates
an appreciable amount more than any other in the set. If yes that fastener
could be stretching.
Regards,
Rob M.
USAussie
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of dave silva
Sent: Sunday, November 28, 2010 4:23 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Loose head bolts
I think I was pretty careful with the sequence. But alas, the bolts do
appear stretched according to the simple test described on this web site:
http://www.zparts.com/zptech/tech_tips/kbtt/pages/tech_tip2b.html
Any recomended vendor?
Gven that the leak was clearly visible near where I had one of the loose
bolts, and given the pristine appearance of the head (only 25,000 miles) I
feel pretty good about the diagnosis.
But I'll look closely at the head surface before Idothis again.
thanks
--
Dave & Ellen Silva
Happy owners of a 1972 Flatnose Revcon
Here by the generosity of the GMC community
http://www.davesilva.com/revcon
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] Loose head bolts [message #106965 is a reply to message #106958] |
Sun, 28 November 2010 19:42 |
 |
Hardie Johnson
Messages: 483
Registered: January 2004
Location: Raleigh NC
Karma: 0
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Senior Member |
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| Robert Mueller wrote on Sun, 28 November 2010 19:35 |
Dave,<>My way of torquing stuff is:
Lubricate fasteners with lightly with oil.
1) set the wrench at 1/2 the torque setting
2) torque fasteners
3) set the wrench to 3/4 the torque setting
4) torque fasteners
5) set the wrench to the full torque setting
6) torque fasteners
7) wait a couple of hours and torque at full setting again and note if any fastener rotates
 wait 24 hours and torque at full setting and note if any fastener rotates an appreciable amount more than any other in the set. If yes that fastener could be stretching.
Regards,
Rob M.
USAussie
<>
|
While I agree with your method, it /may/ result in over-torquing if you seek to match original specs. Torque specs will state 'dry' or 'lubricated' Lubricated will result in a more predictable and consistent result, but the actual value may not be the spec you work for.
Torquing is designed to take the bolt load to the point where there is an equal chance of failure in the bolt and the substrate.
I did manage to find a decent lubed/dry chart:
http://www.cncexpo.com/InchBoltTorque.aspx
To further confuse the issue, sometimes the preferred lubricant is locktite or anti-seize. 
In addition there are fastening systems which are designed to take the fasteners PAST yield and they are not reusable bolts in that case. Usually these are thin or no gasket installations. If you use lube for one of these spec'd for dry torque you will over stress the fasteners.
A head gasket with a lot of takeup should be torqued to a lubed bolt spec, I think, which will be about 25% less than dry torque. Just as with our wheel lugs, it is easy to overdo it. I have had the best results by torquing to a lubed spec of 75% and checking later, then retightened if needed.
"works for me, maybe not for you"
Hardie Johnson "Crashj"
1973 26 foot Glacier, White Thing
Raleigh NC
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| Re: [GMCnet] Loose head bolts [message #106968 is a reply to message #106965] |
Sun, 28 November 2010 20:02 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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Senior Member |
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Ok,Now that you have made this as complicated as possible, how about sharing your recomended torque?
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: [GMCnet] Loose head bolts [message #106975 is a reply to message #106968] |
Sun, 28 November 2010 20:21 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Dave,
RTBM! ;-)
Regards,
Rob M.
USAussie
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of dave silva
Sent: Sunday, November 28, 2010 8:02 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Loose head bolts
Ok,Now that you have made this as complicated as possible, how about sharing
your recomended torque?
thanks
--
Dave & Ellen Silva
Happy owners of a 1972 Flatnose Revcon
Here by the generosity of the GMC community
http://www.davesilva.com/revcon
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: Loose head bolts [message #106982 is a reply to message #106945] |
Sun, 28 November 2010 21:04 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| hertfordnc wrote on Sun, 28 November 2010 15:39 |
As many of you may recall, I spent the summer redoing the head and manifold gaskets on my revcon.
I learned a lot and Ii did a lot of other stuff while I was in there, transmission lines, electric fans, etc.
It would all be great except in the end it leaked.
Only on one side.
Today I pulled the manifold and the right head.
The head bolts offered very little resistance. Of all the stupid things I may have done during this job, I'm certain I torqued all the bolts.
Should I have torqued them again? I got lots of advice form guys on this board, and I thought someone said NOT to torque the bolts again.
So what's the deal? Should I have tightend them again after it sat for a while? After it started the first time? After a few miles?
Thanks
|
Dave,
Why the did you have to do this while I am traveling and struggling for wire????
There is not fastening system that does not benefit from a re- torque.
Olds 455 headbolts are not torque to yield, they are the old school 90% proof load family (almost infinitely reuseable). There is far too much information missing here for me to be definitive in short order.
But, before you do anything else, pull the complete set to tension (torque). The leak may stop, but you will probably still have contaminated lube oil to deal with here.
I am currently in the PST time zone and am expecting guests for dinner after a full day.
Please Answer these two questions before I pontificate as to the situation at great and boring length:
What manufacturer and type head gasket did you install?
What type of torque wrench do you own?
(If it is not beam and pointer, when was last calibrated?)
Well, that could be three......
There is a high probability that you did noting wrong (except believe the supplier - more on that when I am not so tired.)
Matt Colie (McCord's aftermarket engineer - when they existed.)
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Loose head bolts [message #107007 is a reply to message #106982] |
Mon, 29 November 2010 01:18 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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Senior Member |
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| Quote: |
mcolie wrote on Sun, 28 November 2010 21:04There is not fastening system that does not benefit from a re- torque.
Olds 455 headbolts are not torque to yield, they are the old school 90% proof load family (almost infinitely reuseable). There is far too much information missing here for me to be definitive in short order.
But, before you do anything else, pull the complete set to tension (torque). The leak may stop, but you will probably still have contaminated lube oil to deal with here.
I am currently in the PST time zone and am expecting guests for dinner after a full day.
Please Answer these two questions before I pontificate as to the situation at great and boring length:
What manufacturer and type head gasket did you install?
What type of torque wrench do you own?
(If it is not beam and pointer, when was last calibrated?)
Well, that could be three......
There is a high probability that you did noting wrong (except believe the supplier - more on that when I am not so tired.)
Matt Colie (McCord's aftermarket engineer - when they existed.)
|
Too Late to try retorquing, I already pulled the head. The leak was severe enough to blow the gasket out in one small spot so it needed to be changed.
I used a common Felpro gasket from Autozone.
I am fairly certain there is some damage to the studs.
When I mate the threads on two studs and hold it up to the light, there is a visible mis-allignment in the threads.
I used a "clicky" type torque wrench. Borrowed from Autozone,
When I do this again I will check the calibration.
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: Loose head bolts [message #107034 is a reply to message #107007] |
Mon, 29 November 2010 11:39 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| Quote: |
mcolie wrote on Sun, 28 November 2010 21:04There is not fastening system that does not benefit from a re- torque.
Olds 455 headbolts are not torque to yield, they are the old school 90% proof load family (almost infinitely reuseable). There is far too much information missing here for me to be definitive in short order.
But, before you do anything else, pull the complete set to tension (torque). The leak may stop, but you will probably still have contaminated lube oil to deal with here.
I am currently in the PST time zone and am expecting guests for dinner after a full day.
Please Answer these two questions before I pontificate as to the situation at great and boring length:
What manufacturer and type head gasket did you install?
What type of torque wrench do you own?
(If it is not beam and pointer, when was last calibrated?)
Well, that could be three......
There is a high probability that you did noting wrong (except believe the supplier - more on that when I am not so tired.)
Matt Colie (McCord's aftermarket engineer - when they existed.)
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hertfordnc wrote on Mon, 29 November 2010 02:18
=> And I am going to answer in-line for clarity (I hate doing this, but it will probably be most easily understood)
Too Late to try retorquing, I already pulled the head. The leak was severe enough to blow the gasket out in one small spot so it needed to be changed.
=> Sorry...
I used a common Felpro gasket from Autozone.
=> Felpro is no longer the Felpro of past years, but lets go with the guess that it is the same part they sold for years. Solid Core non-asbestos with a teflon coating. A piece of facing paper could easily be blown out because the adhesive used to bond the paper to the core was destroyed by the coolant.
I am fairly certain there is some damage to the studs.
=> I hope by studs you mean the cylinderhead bolts. The Olds 455 is not a stud engine and should not be changed to studs without a great deal of background work.
When I mate the threads on two studs and hold it up to the light, there is a visible mis-alignment in the threads.
=> Yeah, they are probably toast. If you suspect they are damaged, it is best to replace them. the only one that is hard to replace is the stud top version and some one said he knows where to get them. If they were damaged by over-tension (torqed too much), the there thread pitch will be expanded above the engaged length. They may also have visibly "necked". A fastener so damaged can easily relax under load (real bad) at any time.
=> Always be sure that the threads in the block are clear and clean before you start. Good way to clean the threads in the block. Take a cheap tap and run it in and back out, then use the long snout on a can of brake cleaner to blow the loose debris out into a rag.
=> You got Robs line on the light oil on the fastener threads.
I used a "clicky" type torque wrench. Borrowed from Autozone,
=> Click type (from a guy that used to have a stable full of them) are the second least reliable. Dial are worst. Beam and pointer are best - they can't come out of calibration and are almost completely bullet proof - and they are inexpensive. Find one and buy it.
When I do this again I will check the calibration.
=> Many of the calibrators I have run into are also out of calibration. I used to have to take mine to a local aircraft FOB that had a NIST tracable calibrator and trained technician. Get a bendy beam type and use a tape flag to set the value for each pass.
thanks
=> New information time....
All bolted systems have creap (fastener tension loss with time or thermal cycles. (End of dicussion)
One of the worst creap situation is joints with composit gaskets and highly loaded fasteners. (Like cylinder head gaskets.)
The first line for a defensive assembly(?) is to get the entire system assemble at full tension and let is sit for a day. The go pull the fasteners to tension in pattern again. If it can be managed, a pull to tension after at least one but not many thermal cycles is a great help.
As the creap in many non-asbestos head gaskets can be in the 30% region and the relation between fastener tension and cylinder pressure is absolutely critical (that is what you are trying to hold in), this retorque (retensioning) amounts to FREE head bolt load with NO Negative side effects.
After a thermal cycle, the fasteners may stick. If they do not move when you pull on them, pull to load and remember where the end of the pointer of you beam wrench is relative to the cylinder head casting. Back the fastener out enough to break it loose and now pull it back to design load (torque). Want to know what you gained? Look at where the wrench pointer is relative to the head now. Tell me how many degrees and I can tell you how much fastener load you just got for free.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Loose head bolts [message #107041 is a reply to message #107034] |
Mon, 29 November 2010 12:41 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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Senior Member |
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Wow.
That is a fantastic breakdown of the process. Thanks for taking the time to share.
But wat is the torque value? I don't remember what I used but I searched around for 455 torque and found more than one answer.
What say this group?
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: Loose head bolts [message #107095 is a reply to message #107041] |
Tue, 30 November 2010 00:13 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| hertfordnc wrote on Mon, 29 November 2010 13:41 |
Wow.
That is a fantastic breakdown of the process. Thanks for taking the time to share.
But what is the torque value? I don't remember what I used but I searched around for 455 torque and found more than one answer.
What say this group?
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It is my pleasure to pass along the results so many hard won lessons.
Yes, the manual says dipped in oil, but there is a risk in doing that. If enough oil ends up in the bottom of the tapped hole, it will hydraulic lack the threads. If this happens, there is no chance that proper fastener tension will be achieved with design tightening torque.
Recommended procedure:
With a pump oil can, run a line of any standard clean engine oil down the threads and about half of the way around the underside of the fastener head. Lay the fasteners out on a clean rag or paper towel for at least several minutes before setting them in place. No oil should drip from them. (Notice how much this ends up looking like Rob's aircraft procedure?)
When I was part of the bolting technology committee, we identified 73 variables that can significantly affect the torque - tension relationship. Cleanliness was a big one. So was underhead and bearing surface condition along with thread conditions. Anything you can do to get the best tension in the cylinder head bolts will not be wasted effort.
Good Luck with the next gasket and don't forget to oil the bores now and change the oil as soon as it is back together. It only takes a few percent of glycol in oil to destroy bearings.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| What about the other head? [message #107108 is a reply to message #107095] |
Tue, 30 November 2010 06:19 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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Senior Member |
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What is the recommended process for replacing the head bolts on the other side?
It doesn't appear to be leaking (dual exhaust, white smoke on one side only)
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: What about the other head? [message #107170 is a reply to message #107108] |
Tue, 30 November 2010 19:38 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| hertfordnc wrote on Tue, 30 November 2010 07:19 |
What is the recommended process for replacing the head bolts on the other side?
It doesn't appear to be leaking (dual exhaust, white smoke on one side only)
thanks
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Dave,
This is a discussion that started with the Olds diesels that used to break headbolts in service (the only common example).
What we (McCord) found to be a satisfactory solution was:
- Start with the engine dead cold and the cooling system know to be depressurized (pop the cap and put it back on)[Actually, this is not any issue in your case.]
- Remove a fastener. Order did not seem to be important, but why risk it....
- If you can, clean the threads (more about this down the page).
- install the new fastener (oiled like any in a good joint assembly) and pull it to full tension.
(Remember, the joint was supposed to be at full tension already, so a step tensioning sequence is unimportant.
- Repeat until you are done...
About cleaning down the deep hole ++
Remember that thread cleanliness was very near the top of things that effect the torque/tension relationship.
Squirt just a little brake cleaner down the hole.
Now clean the threads - this is the trick. . . . .
A gun cleaning brush (.45~.50 cal) would be great, but you can't get them back out because the brush will unscrew from the rod section (that you chucked in a drill motor). I personally conquered this with a locking collar that crushed the end of the cleaning rod, but I have no idea what a normal human might do... Loktite Maybe?? or find a 1/2 brass brush on a long stick ?
Even if you can't brush the holes, now you take the air nozzle that you put a piece of brake tubing in the end of and bent so you aren't in line with the hole when you blow it out into a rag that was wrapped around that piece of brake line.
Things to NOT do.....
Run a gun cleaning brush in the hole and try to back it out. Retrieving it is a bear. - If you can just pull it straight out, that might work once but the brush will probably be toast.
Cut a slot in the end of a wood dowel and wrap cloth on it.
- Kind of the same problem as the brush, but when you reverse the direction of the cloth it unwraps. If you are real lucky, you can fish the cloth out with a bend wire on the third or forth try, but fabric shreds are still stuck in the threads and the fastener won't run home freely.
Remember there is a 1/2 D at the bottom of the hole that is
untapped and so is smaller.
Hopefully I have provided effective guidance and also saved you from some learning experiences.
If I can be any other help - you know where to find me.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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