Astadur head gasket

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Uros Piperski
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Astadur head gasket

Post by Uros Piperski »

Hello all,
I got a couple of Astadur head gaskets for the Fiat/Lancia TC. Only two are in a sealed package, the rest are opened but unused. There is a sticker on the gasket with a warning to only open the packaging prior to installing to avoid damage to the gasket.
My main question is: Is this to avoid physical damage to the gasket, or the gasket material degrades over time when exposed to air?

Is the Astadur gasket suitable for medium to high performance engines? I know they were very good in their time (10-20 years ago?) but are they now obsolete or not in production because of the asbestos content? Since the Astadur gasket is introduced at the same time as the waisted shank stretch/yield bolts and the setup did not require retorque, is it possible that the modern gaskets are also some kind of thermosetting polymer but without asbestos as they also do not require retorque?

How does the Astadur compare to modern MLS head gaskets?

I intend using a Cometic MLS gasket on a high power turbocharged engine and the Astadur on a mild N/A street engine. Would this be correct or you suggest another option?

Thanks,
Uros
Guy Croft
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Re: Astadur head gasket

Post by Guy Croft »

Hi Uros


My main question is: Is this to avoid physical damage to the gasket, or the gasket material degrades over time when exposed to air?


I used to think they would gradually polymerise (go hard) at room temperature, until I bought 16v Integrale gaskets (from Fiat) of exactly the same composition as the Goetze ones. Fiat just supplied them as-is with no sealed packaging.So maybe it doesn't affect them in that way.


Is the Astadur gasket suitable for medium to high performance engines?


Yes definitely, for a non-MLS gasket (multi-layer steel) it is one of the most robust compositions around.

I know they were very good in their time (10-20 years ago?) but are they now obsolete or not in production because of the asbestos content?

All I know is the Lancia VX, 130TC and 105TC types latterly produced by Fiat themselves in Astadur have not been aval for many years. I use other types now.


Since the Astadur gasket is introduced at the same time as the waisted shank stretch/yield bolts and the setup did not require retorque, is it possible that the modern gaskets are also some kind of thermosetting polymer but without asbestos as they also do not require retorque?

Yes, the alternative types I have are thermosetting, I know this because they are specified for use with torque-twist bolts and thus must be, but I do not use torque-twist bolts at all now, far too much stress on the block threads. I use GC 12.9 head bolts and it is not necessary to retorque. There is no functional difference betw a torque-twist bolt and one with a conventional torque-tightening sequence.


How does the Astadur compare to modern MLS head gaskets?


I know that the Astadur OE Fiat head gasket for the 16v Integrale(for example) with 12.9 grade 10mm head bolts will take 17psi boost provided the inlet temperature is maintained below 45 deg C. A good MLS could take 30psi - or more.

I intend using a Cometic MLS gasket on a high power turbocharged engine and the Astadur on a mild N/A street engine. Would this be correct or you suggest another option?

What you propose is correct, yes.

The attached GC 'How To' may be of some help.

GC
Attachments
Gasket & Bolts 10mm.doc
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Guy Croft, owner
Uros Piperski
Posts: 60
Joined: September 4th, 2006, 10:55 pm
Location: Belgrade, Serbia
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Re: Astadur head gasket

Post by Uros Piperski »

Thanks for a detailed and informative reply, Guy!
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