# What thickness head gasket?



## GTIgina (Sep 23, 2004)

My 88 jetta 8v head gasket is done, so my husband wants to get a slight thinner one to raise his compression a bit
So I have 2 questions about head gaskets.
Cometic (sp) said they can make a 0.027,.030,or 0.36 thick. Stock is .051 said Cometic..Is running the .027 Safe?
And last question, Anyone know off hand how much this would raise the stock compression?
Thanx for any help. I tried searching, but couldn't find anything with these sizes of gaskets.


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## TheMajic86GTI (Aug 9, 2009)

*Re: What thickness head gasket? (GTIgina)*

Are u having the head decked also?
Ur motor now probably has somewhere between 9.5:1 to 10:1 cr no way to know for sure unless u have measured and CC'd it.....So i think the .027 would be ok and ud still be under 10.5:1 which is fine...Id probably go with a thicker like .036 and compensate the difference by decking the head .010..


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## GTIgina (Sep 23, 2004)

*Re: What thickness head gasket? (TheMajic86GTI)*

No he is not deacking the head. There really isn't an option for a "local" machine shop out here, Which I think is why he was looking at the .027 one. Oh he said he has a 270"ish" cam in it. Got it used, previous owner didn't know the cam specs either, so I'm presuming he is worried about smacking the valves.


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## GeekWagens (Oct 7, 2009)

*Re: What thickness head gasket? (GTIgina)*

You have the link to the company making those head gaskets?


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## WaterWheels (Aug 14, 2005)

*Re: What thickness head gasket? (GTIgina)*

.027" may or may not be safe. A good, and important, rule of thumb is to maintain at least .030" between the piston and the valves, including the head gasket. So without knowing the valve lift of the camshaft and it the head has already been machined, it would be risky I think. Another issue about doing that is cost. I looked at the Cometic site and the standard gaskets are $95 + shipping. I'm sure you can add at least another $25 for a custom gasket. Even if the custom gasket were the same price, it is too much. And then if for some reason you have to again replace the head gasket in a week or month or year, that's another $95+. 
The difference in static compression would be less then if the head were shaved that same .024" and a much cheaper OEM gasket used. Without working the figures out I would guess the compression would raise about .2 at best, I think less. Side note, I believe the factory is more like .060" compressed, but could be wrong. Even more important is why the need or desire to raise the static compression a tiny bit? Your 88', knowing the engine code would be more exact, I would think has 10:1 compression in factory form. Just what is the purpose of the car, daily driver, race, weekend track, etc?
Last, there should be places near you that can and do do engine machine work. Graf has lots of GI's and at one time they had a racetrack there too. Plus you can mail the head to many German firms which do machine work, cost is not much for shipping. I live about an hour and a half from Graf and if you really need some help feel free to IM me.


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## GTIgina (Sep 23, 2004)

*Re: What thickness head gasket? (WaterWheels)*

http://www.cometic.com is the site.. the custom sizes are the same price as the stock one.
The head has not been shaved and more than likely will not be. We talked to who we got the car from and he says "he's pretty sure its the TT 270 cam." If he doesn't go with the .027 then he will prolly do the .030 one. The car is HIS daily driver, although it has coilovers, poly bushings all around, and a TT exhaust already. 
It's an RV engine code and we havn't seen/heard of a track out here. German Race Wars happen quite often tho. We don't really want to ship it out to a german shop really for a few reasons. I guess he wants to do a 9a?? trans swap, I don't know if I'm gona let him or not tho. 
It's a quick lil beater that's for sure, so a 'Lil more pep isn't bad.


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## GTIgina (Sep 23, 2004)

*Re: What thickness head gasket? (GTIgina)*

Bump.
No one else has any thoughts on this?


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## JoggerNot (Nov 6, 2009)

*Re: What thickness head gasket? (GTIgina)*


_Quote, originally posted by *GTIgina* »_
No one else has any thoughts on this? 

I think its cute your buying ur husband a head gasket for Christmas








Otherwise no :/ Good luck to ya! Keep us posted http://****************.com/smile/emthup.gif


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## GTIgina (Sep 23, 2004)

*Re: What thickness head gasket? (JoggerNot)*

lol well it is his car, and it needs it anyway. I'll dig through the book we have(not a bently) and see if we can find the clearance with the headgasket. If, with a .027 gasket, it still meets the clearance, we will go with that.
Please, if someone has experiance with thinner head gaskets, chime in. Ie the stock gasket with the inner layer removed. I couldn't find that thickness, if anyone has that PLEASE inform us.
thanx


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## o2bad455 (Aug 22, 2003)

*Re: What thickness head gasket? (GTIgina)*

I don't think you can remove the middle layer from the stock 1.8L gasket and still use the remainder, but I think you can remove the middle fiber layer from the metal ABA 2.0L gasket and just use the metals (perhaps with a thin layer of sealer in the sandwich). The middle layer of the ABA gasket is about .040", IIRC, so just the top and bottom bits would be about .020", maybe a tiny bit more with the sealer.


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## GTIgina (Sep 23, 2004)

*Re: What thickness head gasket? (o2bad455)*

Thanks for that info. I couldn't remember which part of what gasket i saw ppl splitting apart and using the smaller sections. It seems the .027 would be thick enough.


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