Author Topic: exhaust manifold cracking  (Read 4424 times)

Offline NCali

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exhaust manifold cracking
« on: February 28, 2015, 12:34:06 pm »
87 2wd 1/2 ton with a 305
  The passenger side exhaust manifold has cracked between #6 and #8 and actually blew a 1/4" hole on the underside.
   Has anyone had this happen? is it getting to hot?
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Offline sbx22

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Re: exhaust manifold cracking
« Reply #1 on: February 28, 2015, 07:31:48 pm »
Time for headers.

Offline Irish_Alley

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Re: exhaust manifold cracking
« Reply #2 on: February 28, 2015, 11:20:23 pm »
doubt its getting too hot. maybe just age and rust, but like said time for new headers or manifolds
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

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Offline FlatBlack77

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Re: exhaust manifold cracking
« Reply #3 on: March 01, 2015, 08:38:05 am »
someone could have been doing key-off exhaust fires. that can do some damage!
"When you are a hammer, everything looks like a nail"
'77 C/10 - 350/350 mild street motor

Offline NCali

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Re: exhaust manifold cracking
« Reply #4 on: March 01, 2015, 05:25:52 pm »
Not sure what a "key off exhaust fire is unless your talking about turning the key off then back on to make it backfire and for me that was fun 20 years before this truck was made.

So I am in Cali and putting headers on that engine would take an act of congress to pass smog
I thought that I read something in the chev manual (posted in the tech section) about stainless steel manifolds, Ill have to see if I can find out more about them
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Offline zieg85

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Re: exhaust manifold cracking
« Reply #5 on: March 01, 2015, 05:36:38 pm »
Is this the one you need?
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline zieg85

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Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Shifty

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Re: exhaust manifold cracking
« Reply #7 on: March 02, 2015, 09:48:38 am »
Just did my passenger side on my 87 as well....better have an A.I.R. tube on hand as well, they don't come apart nicely.   The reason these break is because of loose/missing exhaust hangers and olde age. 
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

98 C2500 ext cab longbed

Offline FlatBlack77

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Re: exhaust manifold cracking
« Reply #8 on: March 02, 2015, 11:23:25 pm »
Not sure what a "key off exhaust fire is unless your talking about turning the key off then back on to make it backfire and for me that was fun 20 years before this truck was made.


thats what im talking about.

not saying you did it but a previous owner/driver could have
"When you are a hammer, everything looks like a nail"
'77 C/10 - 350/350 mild street motor

Offline NCali

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Re: exhaust manifold cracking
« Reply #9 on: March 09, 2015, 08:11:01 pm »
Zieg: no the one I need has the Cali air pipe on it

flat black:   I have been the only one to drive that truck for about 10 years so I know it hasnt been backfired;

I did find the correct manifold at NAPA auto parts for $113.00, new air tube was around $20.00

but my trans went out so that project is on the back burner for now
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