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Old 03-14-2010   #1
bdw18_123
 
Join Date: Apr 2009
Location: Prather, CA
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Default Head Gaskets?

What's the deal with these? Over at CF they are saying you can't get them anymore. Jerry, I notice your site says you are out of the LH ones. Is this just temporary, or are you going to have more made?

I hope it is temporary because I'm going to need them in the future for my LT5 and I don't want to end up paying $500 per gasket because they suddenly became rare and the few that are still around skyrocket in price. And when they are gone, we will all be f***ed.

Enlighten us Jerry...
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-Cams timed to the '93-'95 405HP LT5 stock timing.
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-OBX cat-back exhaust.
[COLOR=DarkRed][B](SOLD - December 2012 [/B][/COLOR][COLOR=DarkRed][B]:hello:)[/B][/COLOR]

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Old 03-14-2010   #2
A26B
 
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Default Re: Head Gaskets?

It's a problem that I've been working on for the last year, and seriously for the last 6 months.
In the interim, until a suitable replacement is available, head gaskets are still available from Kurt White. His website lists;
81 ea 10106177 LH Head Gaskets in stock @ $98.16ea
10 ea 10106176 RH Head Gaskets in stock @ NOT SOLD SEPARATELY, SETS RH & LH ONLY.

Interestingly enough, he indicates the shortage is with the RH head gasket. My experience and that of others has been just the opposite.

As a progress report of sorts: In my research, I've found that the term open deck includes several different concepts, ranging from the LT5 design at one end to designs like the new Chrysler/Dodge engine presently used in NASCAR. The Dodge engine has the cylinder bank cast into the block & is not replaceable. It's open deck, but a cast-in, integral part of the block casting. Head gasket development for an open deck engine of this type is not a problem.

The LT5 engine is a miracle in manufacturing perfection of precision machine work with exacting tolerances, but it presents some problems in being able to verify the flatness of the head gasket deck surface of the individual cylinders as an assembly within the cylinder case from one end to the other and across the block deck. For MLS (multi-layer steel) gaskets, it creates a problem in that Cometic has stated to me, "the MLS head gasket will leak if flatness is over 0.002". Not maybe but will. This is not to say that it can't be achieved, but it's going to require some special tooling and significant skills to be able to check flatness of the cylinder/block considering the cylinders should have a 0.002" ~ 0/003" pride heifght above the block deck.

This issue begs the question about how the stock head gasket achieved the seal. I can only offer my opinion based on knowledge gained during research, but it is by no means represented as "the final answer." The stock gasket is made from a polymer named "Astadur." Its pliable in its new state, but hardens during the heat cycle of the engine during operation. This flexibility permits the gasket to compensate for the tolerance of variance normally incurred in manufacturing and assembly of the LT5 engine, by letting each individual cylinder's combustion seal align to the cylinder deck. Once the gasket hardens, it provides more backing support by becoming stiff & rigid.

The problem with MLS is that they don't have this flexibility and may not have the ability to conform to each individual cylinder deck. Bottm line is I think it's a crap shoot with MLS in the LT5. Maybe you get a seal on all 8 cylinders and maybe you don't. It's a real gamble to take on a headgasket considering engine removal and cam timing. The MLS gasket's greates attribute, rigidity/strength, is its biggest liability for the LT5.

Is Astadur available. In short, no. The gaskets were originally made by Goetze for GM. Goetze has since been acquired by FelPro. FelPro has not returned any of my many calls and emails.

Are there other possibilities for stock replacement? I certainly hope so, but it's not coming easy.

What about the cost for stock replacements? In excess of $300/set.

What about high performance buid solutions (12:1 plus and boosted engines). Also on the board. Certainly expensive, requiring new cylinders/liners/sleeves, but much better than conventional style head gaskets, including Cometic MLS. Pricing & details not ready for publication.

In summary, I'm willing to invest a significant chunk of change to develop a replacement head gasket for the LT5 engine. I'm not willing to do it for a product I don't have confidence in that it will do the job at least as well as the original head gasket. Getting that confidence is the really difficult part. One engine build doesn't guarantee success, but it does require the total investment into up-front tooling & manufacturing costs. Before I do it, I will have to be convinced of a very high degree of certainty.

.....and that's the way it is. Good day
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Old 03-14-2010   #3
bdw18_123
 
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Default Re: Head Gaskets?

Thank you for all that detailed info, Jerry! Makes sense, I'm the type of person that needs to understand exactly how & why things are the way they are, so that info helps me to understand the issue.

And I (and I'm sure everyone else here) really appreciates the hard work you do to help keep these amazing cars going strong after 20 years! It would really suck if all our ZR-1's eventually had to be taken off the road all because of 2 stupid (albeit, very important) gaskets

Hopefully, this headgasket problem can be worked out. I would think that there should be an equivalent polymer material to this "Astadur" stuff, but I know it would take a lot of time and money to find one, if it even exists.
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1990 Corvette ZR-1 [/B][I]
White/Flame Red, #2299, mostly stock, 144K miles.[/I]
-Cams timed to the '93-'95 405HP LT5 stock timing.
-IAT sensor relocated to below front bumper.
-Haibeck hoops installed in airduct.
-OBX cat-back exhaust.
[COLOR=DarkRed][B](SOLD - December 2012 [/B][/COLOR][COLOR=DarkRed][B]:hello:)[/B][/COLOR]

1993 Corvette Coupe
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Old 03-14-2010   #4
limey
 
Join Date: Oct 2008
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Default Re: Head Gaskets?

If it's R/H head gasket you need, the only person i know other than us that has them is Pete, he purchased the remainder of the head gaskets from GM a month or so back.

Send him a PM or post on here, he'll probably sell you just the one gasket, i think he purchased 30 + of them, so i'm sure he still has some left.

It its LH you need, i've plenty in stock.

The problem with us was 18 months go we had that water main burst in our warehouse and i had to scrap nearly $80k worth of parts, that included nearly all our head gaskets.
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Old 03-14-2010   #5
JThomas
 
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Default Re: Head Gaskets?

Thanks for that detailed explanation Jerry. The education continues!
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Old 03-14-2010   #6
Paul Workman
 
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Default Re: Head Gaskets...

Hey, Jerry!

Good info. A Question: What about the boyz building the closed deck conversions for the LT5s? I'm sure Bob G or Pete might have some insight here; love to hear from them on this too, but does the closed deck sleeves approach e.g., Bob G's 427 or Al's 441 or Kevin's 441s alleviate any of this gasket issue?



P.
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Old 03-14-2010   #7
XfireZ51
 
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Default Re: Head Gaskets?

Jerry,

Super information. Thank you for your efforts!
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Old 03-14-2010   #8
Pete
 
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Default Re: Head Gaskets?

Guys stock gaskets work just fine.
A while back i talked to a major Gasket company.

They want $25-$30k for tooling and $5 each gasket all we need is right hand gasket it will work for both just need to cut the oil hole.

So if we order 1000 gaskets 500 sets it comes out to $35 each gasket.
After that they will cost $10 a set.

I brought this up a while ago but fell on deaf ears so i stocked up on head gaskets.
I also had expressed concern on bearings a while back also fell on deaf ears then the whiners came out cause they had to pay almost $1k for bearings that cost $15 to produce.

So for those that are interested raise your hands.

Otherwise you will be paying $500-$1000 for gaskets from the other guy and i don't wanna hear the whiners.

I have plenty heads gaskets for
(1) last me 2 life times
or
(2) make me lots of money

I think MLS will work with the closed deck but majority of LT5's are open deck the other question is who will test them,i don't think any of the boys here will test them on there big $$$ closed decks.

Pete
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Last edited by Pete; 03-15-2010 at 03:52 PM.
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Old 03-14-2010   #9
phrogs
 
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Default Re: Head Gaskets?

ill buy a set


Quote:
Originally Posted by Pete View Post
Guys stock gaskets work just fine.
A while back i talked to a major Gasket company.

They want $25-$30k for tooling and $5 each gasket all we need is right hand gasket it will work for both just need to cut the oil hole.

So if we order 1000 gaskets 500 sets it comes out to $35 each gasket.
After that they will cost $10 a set.

I brought this up a while ago but fell on death ears so i stocked up on head gaskets.
I also had expressed concern on bearings a while back also fell on death ears then the whiners came out cause they had to pay almost $1k for bearings that cost $15 to produce.

So for those that are interested raise your hands.

Otherwise you will be paying $500-$1000 for gaskets from the other guy and i don't wanna hear the whiners.

I have plenty heads gaskets for
(1) last me 2 life times
or
(2) make me lots of money

I think MLS will work with the closed deck but majority of LT5's are open deck the other question is who will test them,i don't think any of the boys here will test them on there big $$$ closed decks.

Pete
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Old 03-14-2010   #10
xlr8nflorida
 
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Default Re: Head Gaskets?

Sorry, it fell on deaf ears

I'd be game.

Last edited by xlr8nflorida; 03-14-2010 at 10:18 PM.
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