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| [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308584] |
Tue, 11 October 2016 17:46  |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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G'day,
I think we have discussed which bolts are best to use for the exhaust manifold but couldn't find a definitive answer searching the
Forum; hence this thread.
I'm sitting at my desk and typing this from memory using the MM and PB as reference.
OEM Bolts
Material: Steel
Grade: ??
Diameter: 3/8 Inch
Thread: 16 Threads Per Inch
Length: 1 1/4 Inches
Lubricant: None
Torque: 25 foot pounds
Query: What material bolt is the best to use for the exhaust manifold?
OEM Bolts
Material:
Grade:
Diameter: 3/8 Inch
Thread: 16 Threads Per Inch
Length: 1 1/4 Inches
Lubricant:
Torque: Foot Pounds
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
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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] Exhaust Manifold Bolts & Lubricants [message #308589 is a reply to message #308584] |
Tue, 11 October 2016 19:29  |
GMC.LES
Messages: 505
Registered: April 2014
Karma: -2
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Rob,
Do you really mean "best", or did you mean to say "reliably adequate"?
I just finished researching bolts for the exhaust manifolds on my turbo powered truck. My application is known for having seized and broken bolts.
For the "best" bolt in a high temp exhaust environment, inconel type material is often recommended, but it gets costly real quick.
For "reliably adequate" fasteners, there are many less costly materials that will suffice. I've seen all kinds of online recommendations, so I'll let everyone else chime in and share their wisdom. I might learn something. :)
Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)
> On Oct 11, 2016, at 6:46 PM, Rob Mueller wrote:
>
> G'day,
>
> I think we have discussed which bolts are best to use for the exhaust manifold but couldn't find a definitive answer searching the
> Forum; hence this thread.
>
> I'm sitting at my desk and typing this from memory using the MM and PB as reference.
>
> OEM Bolts
> Material: Steel
> Grade: ??
> Diameter: 3/8 Inch
> Thread: 16 Threads Per Inch
> Length: 1 1/4 Inches
> Lubricant: None
> Torque: 25 foot pounds
>
> Query: What material bolt is the best to use for the exhaust manifold?
>
> OEM Bolts
> Material:
> Grade:
> Diameter: 3/8 Inch
> Thread: 16 Threads Per Inch
> Length: 1 1/4 Inches
> Lubricant:
> Torque: Foot Pounds
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308590 is a reply to message #308589] |
Tue, 11 October 2016 19:43 |
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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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Les,
HOOLEE DOOLEE !
http://www.zieglerbolt.com/templates/product_listprice.asp?ProductGuid=37C125BHB%2FINC&GroupGuid=58348
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Les Burt
Rob,
Do you really mean "best", or did you mean to say "reliably adequate"?
I just finished researching bolts for the exhaust manifolds on my turbo powered truck. My application is known for having seized and
broken bolts.
For the "best" bolt in a high temp exhaust environment, inconel type material is often recommended, but it gets costly real quick.
For "reliably adequate" fasteners, there are many less costly materials that will suffice. I've seen all kinds of online
recommendations, so I'll let everyone else chime in and share their wisdom. I might learn something. :)
Les Burt
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Unsubscribe or Change List Options:
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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] Exhaust Manifold Bolts & Lubricants [message #308592 is a reply to message #308590] |
Tue, 11 October 2016 20:07 |
GMC.LES
Messages: 505
Registered: April 2014
Karma: -2
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Senior Member |
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Yup.
I looked for inconel studs and found them to be just as costly.
I recall reading here that using a gr8 bolt is a waste of $$ as the heat cycles will degrade it to something similar in strength to a gr5.
Typical 300 series stainless is too soft and will seize into the Head, making future removal lots of fun.
I ended up using the factory recommended bolts on my truck as they were the lowest cost option that came close to providing adequate service life. They appear to be some sort of 400 series stainless, as they are slightly magnetic, but do not rust.
Lots of nickel anti-seize and I'm confident they will survive long enough to keep me happy.
Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)
> On Oct 11, 2016, at 8:43 PM, Rob Mueller wrote:
>
> Les,
>
> HOOLEE DOOLEE !
>
> http://www.zieglerbolt.com/templates/product_listprice.asp?ProductGuid=37C125BHB%2FINC&GroupGuid=58348
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
>
> -----Original Message-----
> From: Les Burt
>
> Rob,
> Do you really mean "best", or did you mean to say "reliably adequate"?
>
> I just finished researching bolts for the exhaust manifolds on my turbo powered truck. My application is known for having seized and
> broken bolts.
>
> For the "best" bolt in a high temp exhaust environment, inconel type material is often recommended, but it gets costly real quick.
>
> For "reliably adequate" fasteners, there are many less costly materials that will suffice. I've seen all kinds of online
> recommendations, so I'll let everyone else chime in and share their wisdom. I might learn something. :)
>
> Les Burt
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308594 is a reply to message #308592] |
Tue, 11 October 2016 22:04 |
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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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G'day,
STOP THE PRESSES!
I just received an off net message from a GMCer I respect greatly and he noted that he replaces the five bolts with steel studs and
steel nuts.
I never thought of that, it makes R&R'ing the manifold easier as you can hang it on the studs and if the nut is seized on the stud
you can cut / grind it off.
Would brass nuts stand up to the heat?
How about stainless steel nuts?
How about Monel:
http://www.zieglerbolt.com/templates/product_listprice.asp?ProductGuid=37CNFH%2FMON&GroupGuid=58348
That's better!
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Les Burt
Sent: Wednesday, October 12, 2016 12:08 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Exhaust Manifold Bolts & Lubricants
Yup.
I looked for inconel studs and found them to be just as costly.
I recall reading here that using a gr8 bolt is a waste of $$ as the heat cycles will degrade it to something similar in strength to
a gr5.
Typical 300 series stainless is too soft and will seize into the Head, making future removal lots of fun.
I ended up using the factory recommended bolts on my truck as they were the lowest cost option that came close to providing adequate
service life. They appear to be some sort of 400 series stainless, as they are slightly magnetic, but do not rust.
Lots of nickel anti-seize and I'm confident they will survive long enough to keep me happy.
Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)
> On Oct 11, 2016, at 8:43 PM, Rob Mueller wrote:
>
> Les,
>
> HOOLEE DOOLEE !
>
> http://www.zieglerbolt.com/templates/product_listprice.asp?ProductGuid=37C125BHB%2FINC&GroupGuid=58348
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
>
> -----Original Message-----
> From: Les Burt
>
> Rob,
> Do you really mean "best", or did you mean to say "reliably adequate"?
>
> I just finished researching bolts for the exhaust manifolds on my turbo powered truck. My application is known for having seized
and
> broken bolts.
>
> For the "best" bolt in a high temp exhaust environment, inconel type material is often recommended, but it gets costly real quick.
>
> For "reliably adequate" fasteners, there are many less costly materials that will suffice. I've seen all kinds of online
> recommendations, so I'll let everyone else chime in and share their wisdom. I might learn something. :)
>
> Les Burt
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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Unsubscribe or Change List Options:
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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] Exhaust Manifold Bolts & Lubricants [message #308595 is a reply to message #308594] |
Tue, 11 October 2016 22:44 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Senior Member |
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Bronze nuts will withstand the strain and heat, I've seen them on some factory exhaust manifold studs at the pipe/manifold connection. Brass is pretty soft and will probably strip unless it is a long nut.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308601 is a reply to message #308584] |
Wed, 12 October 2016 01:25 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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I had multiple problems with steel exhaust bolts on my airplane. An airplane engine runs much hotter than an automotive one since the engine runs %65 to %80 of power for hours on end. I burn 10 to 12 gallons per hour. My EGT runs around 1500 degrees during that time.
I went with steel studs, brass / bronze nuts, and high temp anti-Seize. I usually remove that exhaust every second year to inspect for exhaust leaks. (The cabin heater is wrapped around the muffler so exhaust leaks are a major worry) The brass nuts and anti-seize really worked well for me for the last 25 years or so.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308605 is a reply to message #308589] |
Wed, 12 October 2016 06:29 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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For the past 2-3 change cycles, I've used this McMaster-Carr "high
temperature" threaded rod to make studs:
99065A130 Brass nuts are easy to
remove, but tend to flare out on the loaded side. Since I double-nut them,
that's an annoyance when I loosen the top one and try to remove them both
with a deep socket. Still the best choice I've found.
Ken H.
On Tue, Oct 11, 2016 at 8:29 PM, Les Burt wrote:
> Rob,
> Do you really mean "best", or did you mean to say "reliably adequate"?
>
> I just finished researching bolts for the exhaust manifolds on my turbo
> powered truck. My application is known for having seized and broken bolts.
>
> For the "best" bolt in a high temp exhaust environment, inconel type
> material is often recommended, but it gets costly real quick.
>
> For "reliably adequate" fasteners, there are many less costly materials
> that will suffice. I've seen all kinds of online recommendations, so I'll
> let everyone else chime in and share their wisdom. I might learn something.
> :)
>
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Unsubscribe or Change List Options:
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308612 is a reply to message #308584] |
Wed, 12 October 2016 09:22 |
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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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Ready?
Here he comes.....
Do Not Use Grade 8 fasteners on anything exhaust.
Gr.8 achieve the better strength with a combination of alloy and heat treatment.
The heat treatment can be normalized away at exhaust manifold temperatures.
The alloy encourages galling and seizing.
If you have to use Gr.5, you should still be careful.
Gr.5 achieve their better strength with a lesser alloy and minimal heat treatment.
That amount of heat treatment can be lost, but it will not matter much.
The alloy is still more prone to galling.
The OE fasteners are probably Gr.2 or 3 or maybe a proprietary in the TZE case.
TZE Special Note: The stock fasteners are listed at 300M. That is a higher quality than an off the shelf Gr.2. The grade is not specified.
In any case, use of as much anti-seize and you can will do no harm.
If you have an oxygen sensor, you have to use nickle based anti-seize. The copper based (like Fel-Pro C-5) also contain lead.
What ever you do, DO NOT exceed the manufacture's recommended install torque.
If you go with a stud and a bronze (brass probably won't make it) nut, that is a good idea.
But, if you have a fine thread nut, that will change (probably increase) the fastener tension for the same final torque.
I say "Probably" because there are too many other variables. Stick with the manual.
If you can, do a thermal cycle and then pull on the wrench at the install torque again. If they move, that's nice, and if they don't, leave them alone.
This is largely going to be an artifact of the relaxation of the gasket material. If you get movement, that is "free" clamp load and it is desirable.
This is all based on years in engine development and testing and other relative experience.
I'll go sit down now......
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: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308728 is a reply to message #308726] |
Fri, 14 October 2016 12:54 |
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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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bhayes wrote on Fri, 14 October 2016 13:37Matt Colie wrote on Wed, 12 October 2016 08:22
...Do Not Use Grade 8 fasteners on anything exhaust.
Aww, man, now you tell me! 
Bryan,
If you installed them to no more than specified torque and if you used so much anti-seize it was dripping off when you warmed the engine up, you may be OK.
If not, I really have to suggest that you change them out at the first convenient time.
You do not want the trouble that they can be.
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: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308745 is a reply to message #308732] |
Fri, 14 October 2016 19:12 |
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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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bhayes wrote on Fri, 14 October 2016 14:52Thanks, Matt. I torqued them to the recommended torque that Remflex recommends for their gaskets (don't recall off the top of my head what that is), and used plenty of copper-based anti-seize goo. I really like the stud idea, though. With as many issues as I've had with leaky gaskets over the past few years (most of them of my own doing), the stud route might be a good route to go. Knock on wood I got it right last time...except for the bolts.
Bryan,
As long as it is together, don't mess with it.
The Gr.8 fasteners will get you more consistent loading due to the closer production and better alloy control. And, if you only pulled them to rated for the design fastener, when they stress relieve you will not lose much. The copper anti-sieze should prevent galling and that is all you can hope for with any fastener.
Remflex gaskets are flexible graphite. (That is a material that I was on the leading edge of at McCord.) It has very little relaxation, but it does have some. If you want to make the very best of it, thermal cycle it a couple of times and then pull the fasteners for tension again. You don't need to do anything but put your torque wrench on the heads and pull. You may get a little turn at rated, but it won't be much and what you get is free sealing load. This cannot hurt anything.
Best of luck, you have made some good choices.
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: [GMCnet] Exhaust Manifold Bolts & Lubricants [message #308747 is a reply to message #308745] |
Fri, 14 October 2016 20:20 |
kelvin
Messages: 608
Registered: February 2004
Location: Eugene, OR
Karma: 0
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Senior Member |
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On 10/14/2016 5:12 PM, Matt Colie wrote:
> bhayes wrote on Fri, 14 October 2016 14:52
>> Thanks, Matt. I torqued them to the recommended torque that Remflex recommends for their gaskets (don't recall off the top of my head what that
>> is), and used plenty of copper-based anti-seize goo. I really like the stud idea, though. With as many issues as I've had with leaky gaskets over
>> the past few years (most of them of my own doing), the stud route might be a good route to go. Knock on wood I got it right last time...except for
>> the bolts. :)
> Bryan,
> As long as it is together, don't mess with it.
>
> The Gr.8 fasteners will get you more consistent loading due to the closer production and better alloy control. And, if you only pulled them to rated
> for the design fastener, when they stress relieve you will not lose much. The copper anti-sieze should prevent galling and that is all you can hope
> for with any fastener.
>
> Remflex gaskets are flexible graphite. (That is a material that I was on the leading edge of at McCord.) It has very little relaxation, but it does
> have some. If you want to make the very best of it, thermal cycle it a couple of times and then pull the fasteners for tension again. You don't need
> to do anything but put your torque wrench on the heads and pull. You may get a little turn at rated, but it won't be much and what you get is free
> sealing load. This cannot hurt anything.
>
> Best of luck, you have made some good choices.
>
> Matt
I'd highly recommend a set of these under those nuts.
http://www.appliedgmc.com/prod.itml/icOid/763
The nuts are very prone to coming loose and this fixes that problem
easily, and so far permanently (25,000 miles without a peep), on my coach.
Kelvin
'73 23' in Eugene, OR
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