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Best Practice - Aluminum or HardBlok in manifold? [message #341419] Sat, 02 March 2019 18:30 Go to next message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
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Registered: September 2015
Location: Guemes Island, Washington
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Senior Member
Which is better for filling the GMC cast iron intake manifold crossover, Aluminum or HardBlok?

I've had a recent quote of $100.00 from an aluminum foundry to fill the manifold. I understand it takes about 20 lbs which works out to 3.5 quarts.

Hardblock is $104.00 for their large size, which makes 3 quarts of filler. I would need to buy two of them.

My manifold has a crack, as does another that may be filled at the same time. I will use the Paterson block-off kit as well. (BTW, I've recently seen a block that had these installed and that had been in service for several years. The kit remained on the block and the SS plates were deformed into a 'hump' in the area of the exhaust ports. Presumably hot enough that exhaust heat sent them into the plastic zone and pressure pushed them in (this manifold did not have the crossover filled).


Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341422 is a reply to message #341419] Sat, 02 March 2019 21:07 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Bill, some of the block off plates are formed to fit the manifold.
Mondello, among others are made that way.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

On Sat, Mar 2, 2019, 6:58 PM Bill Van Vlack via Gmclist <
gmclist@list.gmcnet.org wrote:

> Which is better for filling the GMC cast iron intake manifold crossover,
> Aluminum or HardBlok?
>
> I've had a recent quote of $100.00 from an aluminum foundry to fill the
> manifold. I understand it takes about 20 lbs which works out to 3.5 quarts.
>
> Hardblock is $104.00 for their large size, which makes 3 quarts of filler.
> I would need to buy two of them.
>
> My manifold has a crack, as does another that may be filled at the same
> time. I will use the Paterson block-off kit as well. (BTW, I've recently
> seen
> a block that had these installed and that had been in service for several
> years. The kit remained on the block and the SS plates were deformed into a
> 'hump' in the area of the exhaust ports. Presumably hot enough that
> exhaust heat sent them into the plastic zone and pressure pushed them in
> (this
> manifold did not have the crossover filled).
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
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Re: Best Practice - Aluminum or HardBlok in manifold? [message #341423 is a reply to message #341419] Sat, 02 March 2019 21:20 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
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Registered: January 2004
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See this:
http://www.gmcmhphotos.com/photos/g4571-pouring-the-455-crossover.html

Did this and never looked back. If there were cracks, it sealed them. No problems with burn through. JWID


Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: Best Practice - Aluminum or HardBlok in manifold? [message #341424 is a reply to message #341423] Sat, 02 March 2019 22:53 Go to previous messageGo to next message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
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Jim,
These were Patterson block off plates and gaskets.

Bill


Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341425 is a reply to message #341424] Sat, 02 March 2019 23:20 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Registered: May 2010
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Senior Member
Those started out flat. Sounds like your engine has been "run hard and put
up wet".
Check your plug heat range, mechanical advance, and wide open throttle
air fuel mixture. You got a WHOLE BUNCH of heat in that motor.
Jim Hupy

On Sat, Mar 2, 2019, 9:12 PM Bill Van Vlack via Gmclist <
gmclist@list.gmcnet.org wrote:

> Jim,
> These were Patterson block off plates and gaskets.
>
> Bill
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
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Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341426 is a reply to message #341424] Sat, 02 March 2019 23:28 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Location: Belmont, CA
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Lot of you have no idea as to why the intake over heats.
It is caused by your cheap junk mufflers that crests higher restriction on
one , so the exhaust flows to the other side through the intake passage.
So by installing the SS plate and running those cheap car mufflers and
destroying the plate and complaining and thinking pouring in Al which
cannot handle the high temp that our coaches crests as it has to push air
constantly.
Look up the max temp of AL vs SS
They loosen up after a while
And make noise.

On Sat, Mar 2, 2019 at 9:12 PM Bill Van Vlack via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Jim,
> These were Patterson block off plates and gaskets.
>
> Bill
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,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
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341427 is a reply to message #341425] Sat, 02 March 2019 23:55 Go to previous messageGo to next message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
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Jim,
Not my motor - a friends....

Bill


Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341428 is a reply to message #341427] Sun, 03 March 2019 01:18 Go to previous messageGo to next message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
Messages: 419
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Location: Guemes Island, Washington
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Senior Member
Not complaining, just looking for advice. Are bad mufflers really responsible for all the cracked mufflers?

Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
Re: Best Practice - Aluminum or HardBlok in manifold? [message #341429 is a reply to message #341419] Sun, 03 March 2019 09:48 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
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Location: Braselton ga
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Are bad mufflers responsible for cracked mufflers? Of course. Are they (as I suspect you meant) responsible for cracked manifolds? Potentially yes because as Jimmy The K says, if one muffler presents more restriction than the other, the exhaust pressure can and will equalize by a portion of it going through the crossover to the side of least restriction. In some circumstances, this will get the crossover hot enough to crack here and there. Blocking it will preclude this problem. However, it cures the symptom, not the problem. Given a blocked crossover and asymmetric muffler restriction, one side of the engine is going to see more back pressure than the other, also not a great idea. Fix the exhaust and then consider whether blocking or restricting or leaving it be is what you need. Opinions vary on these choices.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: Best Practice - Aluminum or HardBlok in manifold? [message #341430 is a reply to message #341419] Sun, 03 March 2019 09:50 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
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And I have a question for the Exhaust Gurus. My coach has a single muffler with two inputs. Are the two inputs joined together before any of the baffles in this muffler? (If so, there's no great crossover flow).

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341431 is a reply to message #341430] Sun, 03 March 2019 10:49 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Senior Member
There are a couple of configurations of factory exhaust systems. They all
have two mufflers. Followed by a "Y" pipe. Then into a long exhaust pipe
down the passenger side of the coach.
Then, the fun begins. Aftermarket stuff. Double inlet/single outlet is
one configuration that I have seen quite a few of. Tube headers, car
exhaust manifolds, all manner of cobbled up exhausts. Very high quality all
stainless steel mandrel bent 3" end to end systems, straight pipes without
mufflers that terminate at the rear of the coach into a single muffler.
Everyone seems to have a different idea. 403's vs 455's
Jim K has a very high quality bolt in system. He knows what works, and
what does not.
I have been under so many of these coaches I have seen quite a bit of
really poor exhaust work. And a bunch of charred and burned floors. Cheap
stuff will NOT LAST, and in many cases, is a FIRE HAZARD.
It takes a good deal of horsepower to move these 12,000 pound coaches.
Horsepower is Heat. If you make heat at 10000 btu's per second, you need to
be able to SAFELY get rid of heat at that rate, as well.
Engineers test these systems to destruction in closed cell labs as
well as operating vehicles. They have corporate as well as the NTSB
breathing down their necks. GM spent tons of money developing these
systems. For the most part, they did a very thorough job. Just sayin'.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

On Mar 3, 2019 7:51 AM, "Johnny Bridges via Gmclist" <
gmclist@list.gmcnet.org> wrote:

And I have a question for the Exhaust Gurus. My coach has a single muffler
with two inputs. Are the two inputs joined together before any of the
baffles in this muffler? (If so, there's no great crossover flow).


--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me
in hell" - ol Andy, paraphrased


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Re: Best Practice - Aluminum or HardBlok in manifold? [message #341432 is a reply to message #341430] Sun, 03 March 2019 10:58 Go to previous messageGo to next message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
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Senior Member
Thanks for the correction, Johnny. I did mean cracked manifolds above.

I will check the manufacturer and type of the mufflers on my coach, but shouldn't I fill the existing cracked manifold no matter what that shows to keep the cracks from growing? And if one is different than the other, change the mufflers?

Any thoughts on the question in the first post, i.e, not if but how?


Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
Re: Best Practice - Aluminum or HardBlok in manifold? [message #341434 is a reply to message #341432] Sun, 03 March 2019 11:23 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Bill Van Vlack wrote on Sun, 03 March 2019 11:58
Thanks for the correction, Johnny. I did mean cracked manifolds above.

I will check the manufacturer and type of the mufflers on my coach, but shouldn't I fill the existing cracked manifold no matter what that shows to keep the cracks from growing? And if one is different than the other, change the mufflers?

Any thoughts on the question in the first post, i.e, not if but how?
Bill,

Filling and blocking the crossover, no matter how you do it, is a good idea. If you have a cracked intake, that may be a cure for it. This is not a given. While I have not seen, I can imagine scenarios where the filling does not solve all of the problems. It should keep the crack(s) from growing as there will no longer be the thermal stress on the casting.

Without seeing it, I can only guess. Even then, it would just be a better guess.

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
Re: Best Practice - Aluminum or HardBlok in manifold? [message #341435 is a reply to message #341430] Sun, 03 March 2019 11:32 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Johnny Bridges wrote on Sun, 03 March 2019 10:50
And I have a question for the Exhaust Gurus. My coach has a single muffler with two inputs. Are the two inputs joined together before any of the baffles in this muffler? (If so, there's no great crossover flow).

--johnny
Johnny,

There is simply no way to know what happens inside the shell any muffler. Most of the dual inlet mufflers I have seen open have separate second tubes. So, the answer for them would be no. But, I have only seen that one open. By the design criteria to make a two inlet muffler, I would bet most do not have a common first chamber.

The thing you are concerned about (and should be) is that in many low cost mufflers, the tubes are supported by the baffles and those baffles can break loose and stack so as to block the flow. This is a condition that is common only to the mufflers that do not have full length resonator tubes. I would think that this would not be the case in you two inlet can.

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
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341437 is a reply to message #341434] Sun, 03 March 2019 13:01 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Senior Member
Look, I have been running these coaches and working on these to know that
mufflers do not deteriate at same time so the baffles get loose and
restrict flow on one side befor the other and now the higher pressure is
trying to equalize by flowing through the intake.
Also know that our engines operate at much higher load from the aerodynamic
load.
Vaccume reading a car will run close to 20"he , while our coaches run 12-13.
Even an aluminum intake with no exhaust cross over will fail when one
muffler deteriats befor the other.
You can waste time and money filling the cross over and complain later.
Yes in cars and pick ups filling the intake will last, not not in the MH.
If you guys think I'm full of it then do it your wsy

On Sun, Mar 3, 2019 at 9:24 AM Matt Colie via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Bill Van Vlack wrote on Sun, 03 March 2019 11:58
>> Thanks for the correction, Johnny. I did mean cracked manifolds above.
>>
>> I will check the manufacturer and type of the mufflers on my coach, but
> shouldn't I fill the existing cracked manifold no matter what that shows
>> to keep the cracks from growing? And if one is different than the other,
> change the mufflers?
>>
>> Any thoughts on the question in the first post, i.e, not if but how?
>
> Bill,
>
> Filling and blocking the crossover, no matter how you do it, is a good
> idea. If you have a cracked intake, that may be a cure for it. This is
> not a
> given. While I have not seen, I can imagine scenarios where the filling
> does not solve all of the problems. It should keep the crack(s) from
> growing
> as there will no longer be the thermal stress on the casting.
>
> Without seeing it, I can only guess. Even then, it would just be a better
> guess.
>
> Matt
>
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan
> OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,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
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341438 is a reply to message #341422] Sun, 03 March 2019 13:04 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
One can look into Titinium as a block off, but again your covering up the
major defect

On Sun, Mar 3, 2019 at 11:01 AM Jim Kanomata wrote:

> Look, I have been running these coaches and working on these to know that
> mufflers do not deteriate at same time so the baffles get loose and
> restrict flow on one side befor the other and now the higher pressure is
> trying to equalize by flowing through the intake.
> Also know that our engines operate at much higher load from the
> aerodynamic load.
> Vaccume reading a car will run close to 20"he , while our coaches run
> 12-13.
> Even an aluminum intake with no exhaust cross over will fail when one
> muffler deteriats befor the other.
> You can waste time and money filling the cross over and complain later.
> Yes in cars and pick ups filling the intake will last, not not in the MH.
> If you guys think I'm full of it then do it your wsy
>
> On Sun, Mar 3, 2019 at 9:24 AM Matt Colie via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> Bill Van Vlack wrote on Sun, 03 March 2019 11:58
>>> Thanks for the correction, Johnny. I did mean cracked manifolds above.
>>>
>>> I will check the manufacturer and type of the mufflers on my coach, but
>> shouldn't I fill the existing cracked manifold no matter what that shows
>>> to keep the cracks from growing? And if one is different than the
>> other, change the mufflers?
>>>
>>> Any thoughts on the question in the first post, i.e, not if but how?
>>
>> Bill,
>>
>> Filling and blocking the crossover, no matter how you do it, is a good
>> idea. If you have a cracked intake, that may be a cure for it. This is
>> not a
>> given. While I have not seen, I can imagine scenarios where the filling
>> does not solve all of the problems. It should keep the crack(s) from
>> growing
>> as there will no longer be the thermal stress on the casting.
>>
>> Without seeing it, I can only guess. Even then, it would just be a
>> better guess.
>>
>> Matt
>>
>> --
>> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
>> Electronically Controlled Quiet Engine Cooling Fan
>> OE Rear Drum Brakes with Applied Control Arms
>> SE Michigan - Twixt A2 and Detroit
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
>
--
Jim Kanomata
Applied/GMC, Newark,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
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341439 is a reply to message #341435] Sun, 03 March 2019 14:38 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
One thing we do know for absolutely sure. Cast iron, once cracks start,
does not heal itself. It always gets worse. If it is cracked through to the
floor of the inlet tract, it will run like crap when warmed up if something
isn't done to block the crossover.
Jim Hupy

On Sun, Mar 3, 2019, 11:57 AM Matt Colie via Gmclist <
gmclist@list.gmcnet.org wrote:

> Johnny Bridges wrote on Sun, 03 March 2019 10:50
>> And I have a question for the Exhaust Gurus. My coach has a single
> muffler with two inputs. Are the two inputs joined together before any of
> the
>> baffles in this muffler? (If so, there's no great crossover flow).
>>
>> --johnny
>
> Johnny,
>
> There is simply no way to know what happens inside the shell any muffler.
> Most of the dual inlet mufflers I have seen open have separate second
> tubes. So, the answer for them would be no. But, I have only seen that
> one open. By the design criteria to make a two inlet muffler, I would bet
> most do not have a common first chamber.
>
> The thing you are concerned about (and should be) is that in many low cost
> mufflers, the tubes are supported by the baffles and those baffles can
> break loose and stack so as to block the flow. This is a condition that
> is common only to the mufflers that do not have full length resonator
> tubes.
> I would think that this would not be the case in you two inlet can.
>
> Matt
>
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan
> OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341441 is a reply to message #341438] Sun, 03 March 2019 15:24 Go to previous messageGo to next message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
Messages: 419
Registered: September 2015
Location: Guemes Island, Washington
Karma: 14
Senior Member
Jim K,
I suppose the 'best practices' question might be...

"If/when you come across a cracked manifold in a coach with a stock two-muffler exhaust, what is the best way to proceed."

I would be very interested in hearing more information about failures of/because of aluminum filled manifolds.

For the record, I am not complaining or thinking about complaining since whichever way I proceed will be my own decision and I do not complain about them to anyone but me.


Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341445 is a reply to message #341441] Sun, 03 March 2019 18:28 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Just use use common sense. Al has low melting point.
Our coaches are not like Hot rods or cars.
Understand that, and you will listen to people like us that has been
involved.
Like everything , it will work fine for a while, but will start
deteriorating after it goes through cycles.

On Sun, Mar 3, 2019 at 1:55 PM Bill Van Vlack via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Jim K,
> I suppose the 'best practices' question might be...
>
> "If/when you come across a cracked manifold in a coach with a stock
> two-muffler exhaust, what is the best way to proceed."
>
> I would be very interested in hearing more information about failures
> of/because of aluminum filled manifolds.
>
> For the record, I am not complaining or thinking about complaining since
> whichever way I proceed will be my own decision and I do not complain about
> them to anyone but me.
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015.
>
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--
Jim Kanomata
Applied/GMC, Newark,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
Re: [GMCnet] Best Practice - Aluminum or HardBlok in manifold? [message #341451 is a reply to message #341445] Sun, 03 March 2019 20:37 Go to previous messageGo to previous message
Bill Van Vlack is currently offline  Bill Van Vlack   United States
Messages: 419
Registered: September 2015
Location: Guemes Island, Washington
Karma: 14
Senior Member

If the Rockwell AL manifold holds up to exhaust temperatures, why wouldn't aluminum fill + block-off plates?


Bill Van Vlack '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid November 2015.
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