Home » Public Forums » GMCnet » Opinion needed
| Opinion needed [message #94399] |
Mon, 02 August 2010 22:39  |
bernie
Messages: 46
Registered: February 2008
Location: Montreal
Karma: 0
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What's your diagnosis ? I have a 403 with Thorley headers. A couple of weeks ago, I began to hear a sound coming from what seems to be the area where the right header connects to the engine. It sounds like a steam locomotive noise as soon as I press on the gas. More obvious when the engine is under load, like driving away from a red light, or accelerating...The sound is always present but less noticeable at cruising speed. If the revs go up, so does the sound( It matches the revs, in fact). I replaced the gasket between the engine and the header, but it is still there. Is it possible that the header is cracked? Should I remove the header to inspect it more properly ? I can post a small video if needed!!!
Thank you !
Bernard
GMC Transmode 1977
Montreal,Canada
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| Re: Opinion needed [message #94403 is a reply to message #94399] |
Mon, 02 August 2010 22:52  |
jtblank
Messages: 237
Registered: June 2007
Location: Tulare, CA
Karma: 1
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You do know that opinions are like as$holes, everyone has one so this is mine. I had a similar experience before, not in the GMC but my '65 Mustang that has tri-y headers, could not find the leak and tighten and re-gasket the thing only to the same result. Finally took off the header and upon examination there was a tiny leak in the welding between the header tube and the flange. Had it touched up and problem gone.
HTH
John Blankenship
'76 Palm Beach
Tulare, CA
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| Re: Opinion needed [message #94408 is a reply to message #94399] |
Mon, 02 August 2010 23:34 |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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Senior Member |
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| bernie wrote on Mon, 02 August 2010 20:39 |
What's your diagnosis ? I have a 403 with Thorley headers. I replaced the gasket between the engine and the header, but it is still there. Is it possible that the header is cracked? Should I remove the header to inspect it more properly ? I can post a small video if needed!!!
Thank you !
|
I had what I was sure was a leak between my Thorleys and the right head. On closer examination, I found it was the gasket for the plate for the choke heater, to the right of the carb/TBI that was leaking.
I was able to find the source by using a short piece of gas hose. One end on my ear and the other "sniffing" around. I could not hear anything over by the headers, but by that little plate... bingo.
Be careful, if you remove the bolts. I got to drill and tap one of them. I had done all I could and it still twisted off, but it never hurts to soak it and tap on it and try to ease it out.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
[Updated on: Mon, 02 August 2010 23:35] Report message to a moderator |
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| Re: [GMCnet] Opinion needed [message #94423 is a reply to message #94399] |
Tue, 03 August 2010 07:23 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Bernard,
The gasket is blown. Install a new gasket and retighten the bolts
after at least three heating and cooling cycles. Sounds like this
didn't happen after installation. Bolts stretch, shrink,gaskets
expand, shrink. You have to do the above a minimum of three times.
On Mon, Aug 2, 2010 at 8:39 PM, Bernard <danxavfan@gmail.com> wrote:
>
>
> What's your diagnosis ? I have a 403 with Thorley headers. A couple of weeks ago, I began to hear a sound coming from what seems to be the area where the right header connects to the engine. It sounds like a steam locomotive noise as soon as I press on the gas. More obvious when the engine is under load, like driving away from a red light, or accelerating...The sound is always present but less noticeable at cruising speed. If the revs go up, so does the sound( It matches the revs, in fact). I replaced the gasket between the engine and the header, but it is still there. Is it possible that the header is cracked? Should I remove the header to inspect it more properly ? I can post a small video if needed!!!
>
> Thank you !
> --
> Bernard
> GMC Transmode 1977
> Montreal,Canada
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| Re: Opinion needed [message #94424 is a reply to message #94408] |
Tue, 03 August 2010 07:26 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
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| George Beckman wrote on Mon, 02 August 2010 23:34 |
| bernie wrote on Mon, 02 August 2010 20:39 |
What's your diagnosis ? I have a 403 with Thorley headers. I replaced the gasket between the engine and the header, but it is still there. Is it possible that the header is cracked? Should I remove the header to inspect it more properly ? I can post a small video if needed!!!
Thank you !
|
I had what I was sure was a leak between my Thorleys and the right head. On closer examination, I found it was the gasket for the plate for the choke heater, to the right of the carb/TBI that was leaking.
I was able to find the source by using a short piece of gas hose. One end on my ear and the other "sniffing" around. I could not hear anything over by the headers, but by that little plate... bingo.
Be careful, if you remove the bolts. I got to drill and tap one of them. I had done all I could and it still twisted off, but it never hurts to soak it and tap on it and try to ease it out.
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a friend had the exact same thing happen. the carb heater gasket blew out.
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: [GMCnet] Opinion needed [message #94426 is a reply to message #94399] |
Tue, 03 August 2010 07:54 |
Ray Erspamer
Messages: 1707
Registered: May 2007
Location: Milwaukee Wisconsin
Karma: -3
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Senior Member |
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I have Thorley headers and had the same problem. I installed the REMFLEX
gaskets in 06, installed them and torqued them down. NEVER had to re-tighten
them and have never had another problem. I am sold on the REMFLEX gaskets.
Give them a call, they'll get you the right set.
http://catalog.remflex.com/
Ray
Ray & Lisa Erspamer
78 Royale Center Kitchen
TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
________________________________
From: Bernard <danxavfan@gmail.com>
To: gmclist@temp.gmcnet.org
Sent: Mon, August 2, 2010 10:39:34 PM
Subject: [GMCnet] Opinion needed
What's your diagnosis ? I have a 403 with Thorley headers. A couple of weeks
ago, I began to hear a sound coming from what seems to be the area where the
right header connects to the engine. It sounds like a steam locomotive noise as
soon as I press on the gas. More obvious when the engine is under load, like
driving away from a red light, or accelerating...The sound is always present but
less noticeable at cruising speed. If the revs go up, so does the sound( It
matches the revs, in fact). I replaced the gasket between the engine and the
header, but it is still there. Is it possible that the header is cracked? Should
I remove the header to inspect it more properly ? I can post a small video if
needed!!!
Thank you !
--
Bernard
GMC Transmode 1977
Montreal,Canada
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Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
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| Re: [GMCnet] Opinion needed [message #94429 is a reply to message #94423] |
Tue, 03 August 2010 08:41 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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If you purchased the headers from us, we replace that side n/c under our
warranty program.
Header gaskets need to be re torqued couple of times to avoid leaks later.
Never tighten the top center bolt. Only the 4 in line as the top will cause
the unit to tilt and you'll get a leake at the bottom.
On Tue, Aug 3, 2010 at 5:23 AM, Steven Ferguson <botiemad11@gmail.com>wrote:
> Bernard,
> The gasket is blown. Install a new gasket and retighten the bolts
> after at least three heating and cooling cycles. Sounds like this
> didn't happen after installation. Bolts stretch, shrink,gaskets
> expand, shrink. You have to do the above a minimum of three times.
>
> On Mon, Aug 2, 2010 at 8:39 PM, Bernard <danxavfan@gmail.com> wrote:
> >
> >
> > What's your diagnosis ? I have a 403 with Thorley headers. A couple of
> weeks ago, I began to hear a sound coming from what seems to be the area
> where the right header connects to the engine. It sounds like a steam
> locomotive noise as soon as I press on the gas. More obvious when the engine
> is under load, like driving away from a red light, or accelerating...The
> sound is always present but less noticeable at cruising speed. If the revs
> go up, so does the sound( It matches the revs, in fact). I replaced the
> gasket between the engine and the header, but it is still there. Is it
> possible that the header is cracked? Should I remove the header to inspect
> it more properly ? I can post a small video if needed!!!
> >
> > Thank you !
> > --
> > Bernard
> > GMC Transmode 1977
> > Montreal,Canada
> > _______________________________________________
> > GMCnet mailing list
> > List Information and Subscription Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
>
>
>
> --
> Steve Ferguson
> '76 EII
> Sierra Vista, AZ
> Urethane bushing source
> www.bdub.net/ferguson/
> _______________________________________________
> 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:
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Opinion needed [message #94430 is a reply to message #94424] |
Tue, 03 August 2010 08:44 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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If you want to try the Remflex, we carry then in stock.
I have been told that out price is lower than the factory.
On Tue, Aug 3, 2010 at 5:26 AM, fred veenschoten <fredntoni@cox.net> wrote:
>
>
> George Beckman wrote on Mon, 02 August 2010 23:34
> > bernie wrote on Mon, 02 August 2010 20:39
> > > What's your diagnosis ? I have a 403 with Thorley headers. I replaced
> the gasket between the engine and the header, but it is still there. Is it
> possible that the header is cracked? Should I remove the header to inspect
> it more properly ? I can post a small video if needed!!!
> > >
> > > Thank you !
> >
> >
> > I had what I was sure was a leak between my Thorleys and the right head.
> On closer examination, I found it was the gasket for the plate for the choke
> heater, to the right of the carb/TBI that was leaking.
> >
> > I was able to find the source by using a short piece of gas hose. One
> end on my ear and the other "sniffing" around. I could not hear anything
> over by the headers, but by that little plate... bingo.
> >
> > Be careful, if you remove the bolts. I got to drill and tap one of them.
> I had done all I could and it still twisted off, but it never hurts to soak
> it and tap on it and try to ease it out.
>
> a friend had the exact same thing happen. the carb heater gasket blew out.
>
> --
> 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
_______________________________________________
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: Opinion needed [message #94438 is a reply to message #94399] |
Tue, 03 August 2010 09:37 |
voodoolng
Messages: 40
Registered: February 2004
Location: Colo
Karma: 0
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Member |
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I had a loud noise on the right side also very loud with the speed of the engine. I drove with the lid up and still couldn't tell where it was coming from. When I got home from the trip I crawled all over that thing and found that the intake manifold gasket had pushed its way out. The problem was hiding under the wire loom on the right side. It had pushed the intake gasket about 3/4 inch across the top of the runner out on two runner on the right side. I think the air was making all the noise. Upon inspection theres a step on the head and the mr gasket only bits about an 1/8 inch or so at the top. It pushed out and caused all the noise and cause the two cyl. to run lean. The engine still seemed to run fine on the way home.
73 Glacier Voodoo lounge
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| Re: [GMCnet] Opinion needed [message #94440 is a reply to message #94434] |
Tue, 03 August 2010 09:46 |
Ray Erspamer
Messages: 1707
Registered: May 2007
Location: Milwaukee Wisconsin
Karma: -3
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Senior Member |
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MY kind of torque method, 3 to 5 grunts ! WORKS FOR ME GENE !!!
Ray
Ray & Lisa Erspamer
78 Royale Center Kitchen
TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
________________________________
From: Mr.erf ERFisher <mr.erfisher@gmail.com>
To: gmclist@temp.gmcnet.org
Sent: Tue, August 3, 2010 9:01:09 AM
Subject: Re: [GMCnet] Opinion needed
You have to do the above a minimum of three times.
yep, yep, yep
>
I do it every 200 miles till they quit moving.
I "torque them down " - calibrated torque, (a 6 inch end wrench with all I
can give them)
takes 3 to 5 times
gene
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
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| Re: [GMCnet] Opinion needed [message #94444 is a reply to message #94430] |
Tue, 03 August 2010 10:05 |
bernie
Messages: 46
Registered: February 2008
Location: Montreal
Karma: 0
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Member |
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Jim !
It is the Remflex gasket that I ordered from you last month. It seems OK. I will try to re-torque it a couple of times and see
if it solves the problem. The header is not from you. It is at least 10 years old.
Bernard
GMC Transmode 1977
Montreal,Canada
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| Re: [GMCnet] Opinion needed [message #94447 is a reply to message #94423] |
Tue, 03 August 2010 10:11 |
bernie
Messages: 46
Registered: February 2008
Location: Montreal
Karma: 0
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Member |
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Steve;
I installed the new remflex gasket sunday and it changed nothing. Should I expect a change after the retorquing process even if it changed nothing after the new gasket installation on Sunday?
Do miracles happen?
Thanks!
Bernard
GMC Transmode 1977
Montreal,Canada
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| Re: [GMCnet] Opinion needed [message #94449 is a reply to message #94447] |
Tue, 03 August 2010 10:19 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Respectfully, is it the right Remflex gasket -- the one for the header and not the one for the cast iron manifold?
Dennis S
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Bernard <danxavfan@gmail.com>
To: gmclist@temp.gmcnet.org
Sent: Tue, Aug 3, 2010 10:11 am
Subject: Re: [GMCnet] Opinion needed
Steve;
installed the new remflex gasket sunday and it changed nothing. Should I
xpect a change after the retorquing process even if it changed nothing after
he new gasket installation on Sunday?
o miracles happen?
Thanks!
-
ernard
MC Transmode 1977
ontreal,Canada
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MCnet mailing list
ist Information and Subscription Options:
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] Opinion needed [message #94481 is a reply to message #94429] |
Tue, 03 August 2010 15:01 |
Chr$
Messages: 2690
Registered: January 2004
Location: Scottsdale, AZ
Karma: 1
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Senior Member |
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Jim, this top bolt thing the same with the regular manifolds? I have a leak too...
| jimk wrote on Tue, 03 August 2010 06:41 |
If you purchased the headers from us, we replace that side n/c under our
warranty program.
Header gaskets need to be re torqued couple of times to avoid leaks later.
Never tighten the top center bolt. Only the 4 in line as the top will cause
the unit to tilt and you'll get a leake at the bottom.
On Tue, Aug 3, 2010 at 5:23 AM, Steven Ferguson <botiemad11@gmail.com>wrote:
> Bernard,
> The gasket is blown. Install a new gasket and retighten the bolts
> after at least three heating and cooling cycles. Sounds like this
> didn't happen after installation. Bolts stretch, shrink,gaskets
> expand, shrink. You have to do the above a minimum of three times.
>
> On Mon, Aug 2, 2010 at 8:39 PM, Bernard <danxavfan@gmail.com> wrote:
> >
> >
> > What's your diagnosis ? I have a 403 with Thorley headers. A couple of
> weeks ago, I began to hear a sound coming from what seems to be the area
> where the right header connects to the engine. It sounds like a steam
> locomotive noise as soon as I press on the gas. More obvious when the engine
> is under load, like driving away from a red light, or accelerating...The
> sound is always present but less noticeable at cruising speed. If the revs
> go up, so does the sound( It matches the revs, in fact). I replaced the
> gasket between the engine and the header, but it is still there. Is it
> possible that the header is cracked? Should I remove the header to inspect
> it more properly ? I can post a small video if needed!!!
> >
> > Thank you !
> > --
> > Bernard
> > GMC Transmode 1977
> > Montreal,Canada
> > _______________________________________________
> > GMCnet mailing list
> > List Information and Subscription Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
>
>
>
> --
> Steve Ferguson
> '76 EII
> Sierra Vista, AZ
> Urethane bushing source
> www.bdub.net/ferguson/
> _______________________________________________
> 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 begin_of_the_skype_highlighting 1-800-752-7502 end_of_the_skype_highlighting
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-Chr$: Perpetual SmartAss
Scottsdale, AZ
77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
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| Re: [GMCnet] Opinion needed [message #94498 is a reply to message #94481] |
Tue, 03 August 2010 16:43 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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""Jim, this top bolt thing the same with the regular manifolds? I have a leak too...
""
I'm not Jim, but yes , absolutely! Dave Lanzi first tipped me off to that.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Opinion needed [message #94562 is a reply to message #94449] |
Wed, 04 August 2010 07:30 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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What Dennis said! Easy mistake to make, ask me how I know.
On Tue, Aug 3, 2010 at 8:19 AM, <dennisfsexton@aol.com> wrote:
> Respectfully, is it the right Remflex gasket -- the one for the header and not the one for the cast iron manifold?
>
>
> Dennis S
> 73 GMC
> Germantown, TN
> USA
>
>
>
> -----Original Message-----
> From: Bernard <danxavfan@gmail.com>
> To: gmclist@temp.gmcnet.org
> Sent: Tue, Aug 3, 2010 10:11 am
> Subject: Re: [GMCnet] Opinion needed
>
>
>
> Steve;
> installed the new remflex gasket sunday and it changed nothing. Should I
> xpect a change after the retorquing process even if it changed nothing after
> he new gasket installation on Sunday?
> o miracles happen?
> Thanks!
> -
> ernard
> MC Transmode 1977
> ontreal,Canada
> ______________________________________________
> MCnet mailing list
> ist Information and Subscription Options:
> ttp://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
>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| top bolt [message #94565 is a reply to message #94498] |
Wed, 04 August 2010 08:29 |
bukzin
Messages: 840
Registered: April 2004
Location: North California
Karma: 0
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Senior Member |
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| Bob de Kruyff wrote on Tue, 03 August 2010 14:43 |
""Jim, this top bolt thing the same with the regular manifolds? I have a leak too...
""
I'm not Jim, but yes , absolutely! Dave Lanzi first tipped me off to that.
|
What is meant by the 'top bolt'?
Thanks
Bukzin
1977 Palm Beach
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| Re: top bolt [message #94568 is a reply to message #94565] |
Wed, 04 August 2010 08:39 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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| bukzin wrote on Wed, 04 August 2010 07:29 |
| Bob de Kruyff wrote on Tue, 03 August 2010 14:43 |
""Jim, this top bolt thing the same with the regular manifolds? I have a leak too...
""
I'm not Jim, but yes , absolutely! Dave Lanzi first tipped me off to that.
|
What is meant by the 'top bolt'?
Thanks
|
It's the top bolt near the centerline of the manifold.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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