Author Topic: Header gaskets  (Read 5754 times)

Offline 1979C20

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Header gaskets
« on: February 02, 2011, 12:28:40 PM »
So, when I got my headers, I used mr gasket paper header gaskets. After about 2 months, right around when it got cold, the center top part of each exhaust port the gasket blew out. I ran it for about 2 leaks, terrible backfiring and exhausy leak. Last night I went and bought some more header gaskets, checker's spectre brand because theyre 3 times as thick. Replaced them at my buddies house. Drove home. When I first started my truck, the header pipes were smoking like crazy. I figured it was grease from my hands. Smelled stuff burning the hole way home. Started hearing an exhausy leak. I figured it was okay since you have to re tighten the bolts after its hot. Well, I popped the hood this morning after driving to work to make sure my plug wires and temp sensor wire were off the headers and the center 2 ports on both sides of the block were blown out again. What gives?!
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline jaredts

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Re: Header gaskets
« Reply #1 on: February 02, 2011, 01:45:16 PM »
When you take them loose again to replace the gaskets check the flanges with a straight edge to make sure they're not warped.

Offline 86silverado

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Re: Header gaskets
« Reply #2 on: February 02, 2011, 03:32:46 PM »
you can also cut the flange in between each pipe and that will allow them to tighten up against motor alot better and wont distort flange as bad, did that on my last truck and never gave a problem

Offline 1979C20

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Re: Header gaskets
« Reply #3 on: February 02, 2011, 04:53:33 PM »
My dad HAD to do that on one of our jeeps because he couldn't get the bolts to line up. I'm gonna go back to checker with the receipt and have one of the guys go out and look at the gaskets to show their blown out and see if they will let me do the exchange and take the old gaskets back after swapping them.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline ohio hab

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Re: Header gaskets
« Reply #4 on: February 03, 2011, 04:56:21 PM »
I also would check for warpage. I run copper gaskets, and never had a problem, and they are reusable.

Offline screamin86

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Re: Header gaskets
« Reply #5 on: February 03, 2011, 05:06:07 PM »
After having similar troubles I started using the $5 stock exhaust manifold gaskets the three piece ones that are paper on one side and metal on the other. The ones I'm using now have been on the truck for a year and I reused them when I changed my heads and have no leaks.
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons

Offline 1979C20

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Re: Header gaskets
« Reply #6 on: February 03, 2011, 05:19:13 PM »
So the stock exhaust manifold gaskets are working for you? I was considering the felpro metal crushable gaskets. If the stock ones work for you I'll grab them on the way home.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline screamin86

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Re: Header gaskets
« Reply #7 on: February 03, 2011, 05:40:49 PM »
Yeah I ran them on one of my cars for the longest time too. They are like any other though you have to retighten them a few times especialy at first. I use allen bolts on all my headers and keep a set of wrenches in the glovebox all the time.
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons

Offline 1979C20

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Re: Header gaskets
« Reply #8 on: February 03, 2011, 11:00:30 PM »
Okay, went to checker, bought 2 pair of mr gasket metal gaskets and copper sprayed them together. Just need to re tightenn the bolts now. Sounds soooo much better meow.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline bobcooter

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Re: Header gaskets
« Reply #9 on: February 04, 2011, 09:35:37 AM »
I ran these on my truck when I had headers. I put 20,000 miles on them with no issues at all. I also used the Summit copper collector gaskets with no issues as well.

http://www.summitracing.com/parts/SUM-111405/?rtype=10
'79 C-20, 350/400, 3:73 gears, 9 leafs and a headache rack
Favorite Quote, "Good judgement comes from experience. Experience comes from poor judgement."

Offline 1979C20

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Re: Header gaskets
« Reply #10 on: February 04, 2011, 12:12:27 PM »
If I have a problem with these I'll look into it, but I need square port. Probably same price right?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline bobcooter

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Re: Header gaskets
« Reply #11 on: February 04, 2011, 12:31:47 PM »
Yeah, same price.
'79 C-20, 350/400, 3:73 gears, 9 leafs and a headache rack
Favorite Quote, "Good judgement comes from experience. Experience comes from poor judgement."

Offline slammed79

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Re: Header gaskets
« Reply #12 on: February 04, 2011, 12:49:42 PM »
I've also used the stock manifold gaskets with a set of Hooker long tubes and the Mr. Gasket aluminum collector gaskets, no problems at all. I also used slightly longer bolts and lock washers, sealed up perfect
74 C10 Long bed 350/SM465 Lowered on 20's

Praise the lowered

Offline 1979C20

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Re: Header gaskets
« Reply #13 on: February 05, 2011, 01:13:33 AM »
Well I tightened, and retightened the crap out of them, the gasket is flat but the flange bubbles out in the middle like a 1/32". So, silicone is next. Doesnt matter if their warped. About a quarter inch thick bead of silicone around each port, let em dry for like 2 hours, and torque em down. jyst like sprint cars do.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline screamin86

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Re: Header gaskets
« Reply #14 on: February 05, 2011, 05:49:12 AM »
Have you tried lossening the bolts then starting with the middle ports first then work to the outer parts of the flanges? I have a friend with a 68 dodge charger who is having a similar issue and that's what he had to do. I had aluminum collector gaskets on my truck that I had a machinest at work make me they work great and when my exhaust guy built my exhaust he siliconed them when he put them back on and I've had no collector leaks or flange leaks using the manifold gaskets.
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons