# metal head gasket
**URL:** https://forums.speedlife.net/t/metal-head-gasket/98481
**Category:** SON240sx Automotive
**Created:** [July 31, 2006, 1:40pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481 "2006-07-31T13:40:12Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@matty](https://forums.speedlife.net/u/matty)
#### Post date: [July 31, 2006, 1:40pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/1 "2006-07-31T13:40:12Z")
looking to get a greddy metal head gasket.
oticed they have difefrent thickness sizes rangin from 1.2 -1.8.
allof which have the same bore and are the same price.
whats the dif?
im looking to put it on a daily driver with occasonal track use.
can someone clarify for me.
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### Author:  [@Lith](https://forums.speedlife.net/u/Lith)
#### Post date: [July 31, 2006, 2:43pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/2 "2006-07-31T14:43:55Z")
I might be wrong here, but wouldn’t this raise/lower your overall compression ratio? Also, what is the thinkness of the stock headgasket? Try to match it, if you just wanna keep it at the stock compression ratio.
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### Author:  [@matty](https://forums.speedlife.net/u/matty)
#### Post date: [July 31, 2006, 5:51pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/3 "2006-07-31T17:51:26Z")
any body here rcking a metal head gasket?
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### Author:  [@robbbby](https://forums.speedlife.net/u/robbbby)
#### Post date: [July 31, 2006, 6:24pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/4 "2006-07-31T18:24:02Z")
The thickness will raise/lower your compression a little. Different thickness’ can also compensate for mill/deck work done to your cylinder block or head.
I run a 0.8mm apexi gasket.
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### Author:  [@AppleSauce](https://forums.speedlife.net/u/AppleSauce)
#### Post date: [July 31, 2006, 6:43pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/5 "2006-07-31T18:43:37Z")
A lot more people seem to have better luck sealing with the apexi head gasket than the greddy one.
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### Author:  [@KoukiS14](https://forums.speedlife.net/u/KoukiS14)
#### Post date: [July 31, 2006, 7:19pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/6 "2006-07-31T19:19:32Z")
> [@AppleSauce](#):
>
> A lot more people seem to have better luck sealing with the apexi head gasket than the greddy one.
I concur, the GReedy head gasket seems to have caused some headaches for people. User error or not, I would rather go with APEXi.
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### Author:  [@matty](https://forums.speedlife.net/u/matty)
#### Post date: [July 31, 2006, 9:58pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/7 "2006-07-31T21:58:07Z")
whcih thicknesses will raiise or lower cmpression and to how much roughly?
anybody know?
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### Author:  [@G-E](https://forums.speedlife.net/u/G-E)
#### Post date: [August 1, 2006, 1:43pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/8 "2006-08-01T13:43:08Z")
find out the chamber volume before and after, then you can calculate what the squish percentage is … makes a good estimate
once you do it you can check the compression readings and back-calc the ratio, prior to doing it you need to know lotsa numbers and calc stuff
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### Author:  [@robbbby](https://forums.speedlife.net/u/robbbby)
#### Post date: [August 1, 2006, 1:47pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/9 "2006-08-01T13:47:22Z")
> [@matty](#):
>
> whcih thicknesses will raiise or lower cmpression and to how much roughly?
>
> anybody know?
That all depends on your motor. There is a bit of math involved, here is a spreadsheet courtesy of enthalpy to figure it out.
[http://www.rs-enthalpy.com/tuning/sr-compcalc.xls](http://www.rs-enthalpy.com/tuning/sr-compcalc.xls)
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### Author:  [@bing](https://forums.speedlife.net/u/bing)
#### Post date: [August 1, 2006, 1:47pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/10 "2006-08-01T13:47:37Z")
i use cometics.
.8 or .88 mm is stock thickness, one of the two.
user or install error is the only cause of failure on metal headgaskets on motors running less than 300whp.
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### Author:  [@Happy240sx](https://forums.speedlife.net/u/Happy240sx)
#### Post date: [August 1, 2006, 2:06pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/11 "2006-08-01T14:06:44Z")
I’m pretty sure that stock SR headgasket replacement thickness is 1.1mm… not 0.8mm
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### Author:  [@jammin1911](https://forums.speedlife.net/u/jammin1911)
#### Post date: [August 1, 2006, 2:20pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/12 "2006-08-01T14:20:54Z")
^^ maybe this is why bing was giddy about how much power his motor made and then blew it up? 😃
j/p bingx0r
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### Author:  [@Happy240sx](https://forums.speedlife.net/u/Happy240sx)
#### Post date: [August 1, 2006, 2:30pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/13 "2006-08-01T14:30:51Z")
0.8mm vs. 1.1mm will not make much of a diff anyway. You’ll still be under 9.0:1 compression.
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### Author:  [@robbbby](https://forums.speedlife.net/u/robbbby)
#### Post date: [August 1, 2006, 3:15pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/14 "2006-08-01T15:15:54Z")
> [@Happy240sx](#):
>
> 0.8mm vs. 1.1mm will not make much of a diff anyway. You’ll still be under 9.0:1 compression.
Depends on machine work and piston selection as well though, unless you are talking about a strictly stock motor.
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### Author:  [@Happy240sx](https://forums.speedlife.net/u/Happy240sx)
#### Post date: [August 1, 2006, 3:19pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/15 "2006-08-01T15:19:25Z")
Yeah - I’m just talking stock replacement.
You certainly can’t go slapping in a 0.8mm HG with domed pistons and a few thou taken from the head without knowing your ultimate goal.
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### Author:  [@AppleSauce](https://forums.speedlife.net/u/AppleSauce)
#### Post date: [August 1, 2006, 6:25pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/16 "2006-08-01T18:25:09Z")
> [@KoukiS14](#):
>
> [quote=AppleSauce]A lot more people seem to have better luck sealing with the apexi head gasket than the greddy one.
I concur, the GReedy head gasket seems to have caused some headaches for people. User error or not, I would rather go with APEXi.[/quote]
Yah… that’s what I said???
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### Author:  [@bing](https://forums.speedlife.net/u/bing)
#### Post date: [August 1, 2006, 7:33pm UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/17 "2006-08-01T19:33:35Z")
> [@Happy240sx](#):
>
> I’m pretty sure that stock SR headgasket replacement thickness is 1.1mm… not 0.8mm
O RLY…
i was pretty sure 1.1 was an upgrade as i get pitched the mentioned sizes as stock, but i wont argue with danny-boy.
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### Author:  [@Hurricane](https://forums.speedlife.net/u/Hurricane)
#### Post date: [August 2, 2006, 5:34am UTC](https://forums.speedlife.net/t/metal-head-gasket/98481/18 "2006-08-02T05:34:14Z")
1.1mm should be stock from what I’ve been told… atleast it better be as thats what I ordered!.. when ever it gets here.
Apexi is the only HG worth buying IMO.