| exhaust manifold gasket challenge [message #91141] |
Mon, 05 July 2010 12:13  |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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I held a freshly machined manifold up against my freshly cleaned head and there is a visible gap of about .030" on the top of two ports.
i suppose i should have stopped right there and got the head milled but the other head was already bolted in so I took a chance and installed it.
Historically I'd had a problem getting the manifolds to not leak. I had some success using TWO regular Felpro gaskets.
So, what's the best option?
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] exhaust manifold gasket challenge [message #91143 is a reply to message #91141] |
Mon, 05 July 2010 12:43  |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Remflex.
Dennis
Germantown, TN
USA
-----Original Message-----
From: dave silva <gmc@davesilva.com>
To: gmclist@temp.gmcnet.org
Sent: Mon, Jul 5, 2010 12:13 pm
Subject: [GMCnet] exhaust manifold gasket challenge
I held a freshly machined manifold up against my freshly cleaned head and there
s a visible gap of about .030" on the top of two ports.
i suppose i should have stopped right there and got the head milled but the
ther head was already bolted in so I took a chance and installed it.
Historically I'd had a problem getting the manifolds to not leak. I had some
uccess using TWO regular Felpro gaskets.
So, what's the best option?
Thanks
-
EW SIG !!!
FREE GMC PARTS - tanks, glass, bogies, and corners. Come get 'em. make a
onation to the disposal fund. zip 27944 one hour from Norfolk VA and the Outer
anks
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MCnet mailing list
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] exhaust manifold gasket challenge [message #91149 is a reply to message #91141] |
Mon, 05 July 2010 13:22 |
powerjon
Messages: 2446
Registered: January 2004
Karma: 5
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Senior Member |
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Dave,
You want to use the Remflex Gaskets. 2300 Deg F safe and will
last. Jim K has the best pricing on the gasket anywhere, you won't
find them cheaper even with the shipping.
http://www.appliedgmc.com/prod.itml/icOid/670
J.R. Wright
GMC GreatLaker
TZE Zone Restorations
77 Eleganza Custom (For Sale)
1975 Avion (Under Reconstruction)
Michigan
On Jul 5, 2010, at 1:13 PM, dave silva wrote:
>
>
> I held a freshly machined manifold up against my freshly cleaned
> head and there is a visible gap of about .030" on the top of two
> ports.
>
> i suppose i should have stopped right there and got the head milled
> but the other head was already bolted in so I took a chance and
> installed it.
>
> Historically I'd had a problem getting the manifolds to not leak. I
> had some success using TWO regular Felpro gaskets.
>
> So, what's the best option?
>
> Thanks
>
>
> --
> NEW SIG !!!
>
> FREE GMC PARTS - tanks, glass, bogies, and corners. Come get 'em.
> make a donation to the disposal fund. zip 27944 one hour from
> Norfolk VA and the Outer Banks
>
>
> _______________________________________________
> 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:
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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
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| Re: [GMCnet] exhaust manifold gasket challenge [message #91161 is a reply to message #91151] |
Mon, 05 July 2010 15:33 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Bruce,
A length of rubber hose held near the ear (not in the ear) works as a nice stethoscope to locate any possible leaks.
Good question on the copper and heat transfer -- when it was raised before we did not have any data on the use of the Remflex gaskets. Now, perhaps some two years later, I have not heard of any cracks which were attributed to the Remflex.
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Bruce Hislop <bruce@perthcomm.com>
To: gmclist@temp.gmcnet.org
Sent: Mon, Jul 5, 2010 2:01 pm
Subject: Re: [GMCnet] exhaust manifold gasket challenge
I'll vote for Remflex too.
Anyone have any knowledge on the heat transfer abilities of the Remflex?
I had Remflex before the engine rebuild, then I had the manifolds plained and
ot Dick Lenzi's copper gaskets for the fresh engine. I'd like to stay with the
opper, but I think I have a leak again.
But I'm under the understanding that the manifolds run much hotter with other
ypes of gaskets and crack easier.
thanks
-
ruce Hislop,
. Ontario Canada
7PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI and ESC.
ttp://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
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MCnet mailing list
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] exhaust manifold gasket challenge [message #91171 is a reply to message #91161] |
Mon, 05 July 2010 17:25 |
Rick Denney
Messages: 430
Registered: January 2004
Karma: 0
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Senior Member |
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| Dennis Sexton wrote on Mon, 05 July 2010 16:33 |
Good question on the copper and heat transfer -- when it was raised before we did not have any data on the use of the Remflex gaskets. Now, perhaps some two years later, I have not heard of any cracks which were attributed to the Remflex.
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Couple of features of the Remflex that might address the issue: 1.) they remain flexible, unlike many ceramic composite "gap-filling" gaskets of the past. Thus they might allow the manifold to move around without it stressing to the point of cracking, and without developing leaks.
2.) the carbon composite core of the Remflex might not be that bad at transferring heat. I don't know, but I would not discount it out of hand. Maybe it would do better than a conventional fiber gasket.
In any case, the proof of the pudding is in the tasting, and so far the Remflexes taster pretty good.
Rick "who would recommend nothing else for headers in any case" Denney
'73 Glacier 230 "Jaws"
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| Re: exhaust manifold gasket challenge [message #91180 is a reply to message #91151] |
Mon, 05 July 2010 18:17 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
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| RF_Burns wrote on Mon, 05 July 2010 14:01 |
I'll vote for Remflex too.
Anyone have any knowledge on the heat transfer abilities of the Remflex?
I had Remflex before the engine rebuild, then I had the manifolds plained and got Dick Lenzi's copper gaskets for the fresh engine. I'd like to stay with the copper, but I think I have a leak again.
But I'm under the understanding that the manifolds run much hotter with other types of gaskets and crack easier.
thanks
|
from what i understand the original had no gasket and the manifold would loose it's heat into the head. the copper gasket will do the same thing.
i had my manifold plained or sanded flat and use the Patterson gasket with good success.
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: [GMCnet] exhaust manifold gasket challenge [message #91197 is a reply to message #91180] |
Mon, 05 July 2010 21:20 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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You can mill down the manifold only so much before the manifold will kiss
the block.
You'll not notice that unless it's on a engine stand or check from below.
There must be a bad muffler or a restriction to cause problems so soon.
On Mon, Jul 5, 2010 at 4:17 PM, fred veenschoten <fredntoni@cox.net> wrote:
>
>
> RF_Burns wrote on Mon, 05 July 2010 14:01
> > I'll vote for Remflex too.
> >
> > Anyone have any knowledge on the heat transfer abilities of the Remflex?
> >
> > I had Remflex before the engine rebuild, then I had the manifolds plained
> and got Dick Lenzi's copper gaskets for the fresh engine. I'd like to stay
> with the copper, but I think I have a leak again.
> >
> > But I'm under the understanding that the manifolds run much hotter with
> other types of gaskets and crack easier.
> >
> > thanks
>
> from what i understand the original had no gasket and the manifold would
> loose it's heat into the head. the copper gasket will do the same thing.
>
> i had my manifold plained or sanded flat and use the Patterson gasket with
> good success.
>
> --
> Fred V
> '77 Royale RB 455
> P'cola, Fl
> _______________________________________________
> 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
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: exhaust manifold gasket challenge [message #91204 is a reply to message #91141] |
Tue, 06 July 2010 03:36 |
jtblank
Messages: 237
Registered: June 2007
Location: Tulare, CA
Karma: 1
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Senior Member |
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I changed my OEM manifold gaskets to Remflex a couple of years ago and probably 3K miles and so far no leaks, I did have the manifold surfaced level before installing. My trips take me through both the Coastal and Sierra Nevada mountains here in California that require full throttle going up grades that pulls the MPH to 40 in second and undoubtedly gets them cherry red. So Far So Good! They get my vote.
John Blankenship
'76 Palm Beach
Tulare, CA
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| Re: [GMCnet] exhaust manifold gasket challenge [message #91217 is a reply to message #91212] |
Tue, 06 July 2010 07:12 |
Rick Denney
Messages: 430
Registered: January 2004
Karma: 0
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Senior Member |
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| pete lyons wrote on Tue, 06 July 2010 07:29 |
Can these be used on Thorleys?
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Yes, absolutely.
One of my original Thorley gaskets was lost to the intake-manifold leak situation I had a couple of years ago, which soaked the gasket in oil and then burned it away. I replace it with a Remflex. The other Remflex gasket is waiting until the other side fails.
Remember to follow the Remflex instructions regarding tightening. These gaskets can be ruined by overzealous or repeated tightening.
Rick "thinking these are the best gaskets for the Thorleys" Denney
'73 Glacier 230 "Jaws"
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| Re: [GMCnet] exhaust manifold gasket challenge [message #91233 is a reply to message #91197] |
Tue, 06 July 2010 08:10 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
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Senior Member |
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| jimk wrote on Mon, 05 July 2010 21:20 |
You can mill down the manifold only so much before the manifold will kiss
the block.
You'll not notice that unless it's on a engine stand or check from below.
There must be a bad muffler or a restriction to cause problems so soon.
|
if you plane it down too far it will also pinch the dip stick tube.
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: exhaust manifold gasket challenge [message #91234 is a reply to message #91141] |
Tue, 06 July 2010 08:23 |
 |
RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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Senior Member |
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Jim K:
I had my manifolds plained. Guy said they were way out, there is no raised area around the ports now and some of the body of the manifold was plained as well by their machine. I should have taken before and after pics.
It just "seems" like its leaking there, louder but Dick P. does some tricks on his rebuilds so it could be the engine just sounds different. Also I installed a Wide-Band O2 sensor which reads lean compaired to the NB sensor as if there is a leak allowing O2 into the exhaust.
I asked Borrmann's to check and they found the passenger side donut was leaking and that improved the WB reading.
I'm thinking it may be hitting the block.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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