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LT1 head gaskets

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Old Aug 2, 2004 | 09:26 PM
  #1  
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LT1 head gaskets

I guess Im to the point now where the felpro 1074 head gaskets will not hold anymore cylinder pressure. I keep pushing the fire ring out on the #7 cylinder( twice on 7 once on 8). Its not ripping it by any means. Im not sure what a detnated gasket looks like but I would imagine the gasket would rip. The speed shop also told me these felpro gaskets have a compressed copper ring and you cant get a stainless wire lock for the lt1. From what I have dug up with out doing any o rings is the cometic gaskets. I order up a set and going to throw them in tonight. They look a little more durable then the felpro.

The heads are streight so I didnt have them cut. I measured the head before I did the last set and it was streight for me. After I blew it again I thought maybe my streight edge was maybe off? I took it to the speed shop and they measured both heads and they were streight as can be. I dought the block is worpped considering cast iron is more forgiving then aluminum. Im just thinking these felpro gaskets cant handle the cylinder pressure.

Just thought I would drop my experiance....anyone care to add their exeriance with head gaskets shoot!
Old Aug 2, 2004 | 09:54 PM
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Re: LT1 head gaskets

Good luck with the cometics , I STILL HAVNT BLOWN A FELPRO I just redid my topend after cracking one of my heads but the gaskets held.
Old Aug 2, 2004 | 09:55 PM
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Re: LT1 head gaskets

I never had a problem with the Fel Pro. I think there is another problem that you should fix.

Rich
Old Aug 2, 2004 | 11:30 PM
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Re: LT1 head gaskets

Originally Posted by rskrause
I never had a problem with the Fel Pro. I think there is another problem that you should fix.

Rich
What are you suggesting?

Ohh I went to put on those cometics and the rivets dont clear the block. The gaskets are for a 92-96 LT1, which makes me think of the corvette motor, but it should be the same. All the cooling holes line up. Anyone else experiance this?
Old Aug 2, 2004 | 11:33 PM
  #5  
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Re: LT1 head gaskets

Detonation, overheating, head or deck warped, improper assembly, bad head bolts/studs.

Rich
Old Aug 2, 2004 | 11:57 PM
  #6  
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Re: LT1 head gaskets

Originally Posted by rskrause
Detonation, overheating, head or deck warped, improper assembly, bad head bolts/studs.

Rich
Detonation, overheating, head warped, and improper assembly i know are out of the question. As for bad studs, non of the threads are stretched, other then that can one tell a bad stud? When looking for a warped head we just used a streight edge and a feeler gauge. I would think that would should be sufficent, your thoughts? I guess i should check the block before I assemble it. I should be able to pull the studs and use a streight edge on the block and that should tell me..

I dont want to pull the heads again so any other testing methods you can suggest I would appriciate it.

Thanks
Old Aug 3, 2004 | 12:11 AM
  #7  
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Re: LT1 head gaskets

The Cometics are stronger than the Fel Pro, but a multi-layer steel (MLS) gasket like the Cometic requires an even more critical head and block prep to work correctly. The rigid nature of MLS gaskets means they have very little conformability. They require an extremely smooth, flat surface finish on both the head and the deck. The surfaces should be flat to ~0.002" at most. So, you need a machinists quality straight edge and some feeler gauges to check flatness. The surfaces also must be very smooth for an MLS agsket. The smoother the better - almost polished in appearance. This may be "too smooth" for a conventional gasket, BTW.

Did the gasket fail in the same place? That might indicate local overheating or a local surface problem. Did you use new head bolts? I would. Were they properly torqued in the right sequence? Is your torque wrench accurate?

Rich
Old Aug 3, 2004 | 12:26 AM
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Re: LT1 head gaskets

Originally Posted by rskrause
The Cometics are stronger than the Fel Pro, but a multi-layer steel (MLS) gasket like the Cometic requires an even more critical head and block prep to work correctly. The rigid nature of MLS gaskets means they have very little conformability. They require an extremely smooth, flat surface finish on both the head and the deck. The surfaces should be flat to ~0.002" at most. So, you need a machinists quality straight edge and some feeler gauges to check flatness. The surfaces also must be very smooth for an MLS agsket. The smoother the better - almost polished in appearance. This may be "too smooth" for a conventional gasket, BTW.

Did the gasket fail in the same place? That might indicate local overheating or a local surface problem. Did you use new head bolts? I would. Were they properly torqued in the right sequence? Is your torque wrench accurate?

Rich

The gasket failed along the back of the number 7 closest to the fire wall. That entire side kicked into the cooling ports( about 1/2 the fire ring kick out on the last blow). Im using studs, and I torque them with a beam type wrench. I have had the same studs for a few years..
Old Aug 3, 2004 | 07:21 AM
  #9  
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Re: LT1 head gaskets

Cometics work great for me. When I was trying to decide, I did a bunch of searches and didn't find anyone that had run them that anything bad to say...
Old Aug 3, 2004 | 11:01 AM
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Re: LT1 head gaskets

Its Jake right?? I have seen the car and its very awesome.
I think you have had a couple of gaskets go in about the same area? Correct? If so pay extra attention to the studs in that location, and YES get a straight edge on the block. The blocks can and do warp (multiple failures in the same spot with flat heads tend to make me think the block may have an issue) when you do assemble it I assume you have the block clean enough to eat off of? If the block is ok then it may be the tune BUT if its the tune, it should'nt be poping the gasket in the same spot(there has to be a reason it keeps going in the same spot, is what I am trying to say)
Good luck!
Let me know if you need any help, I am local and have been in working with these for a while....
Old Aug 5, 2004 | 08:32 AM
  #11  
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Re: LT1 head gaskets

I just installed the Cometics last night, and with AFR heads the lower 2 rivets interfere slightly on the drivers side head only. All you do is take tin snips and cut if off. It's only function is to keep the sandwich assembled properly. The pins in the block keep everything aligned once it's installed. The catalog to order them says to do this and I spoke to Tech Support yesterday to confirm...it's not uncommon.
Old Aug 6, 2004 | 02:57 AM
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Re: LT1 head gaskets

Originally Posted by BlownF1
I just installed the Cometics last night, and with AFR heads the lower 2 rivets interfere slightly on the drivers side head only. All you do is take tin snips and cut if off. It's only function is to keep the sandwich assembled properly. The pins in the block keep everything aligned once it's installed. The catalog to order them says to do this and I spoke to Tech Support yesterday to confirm...it's not uncommon.
Yeah I drilled out the rivets. I also have a problem with the intake push rods hitting the gasket a hair.
anyway I had the heads put on a belt sander and the heads turned out to be warped as soon as they were slapped on it.
Old Aug 6, 2004 | 02:18 PM
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Re: LT1 head gaskets

So you found the problem then?
Old Aug 6, 2004 | 03:09 PM
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Re: LT1 head gaskets

Originally Posted by sleeperz28
The gasket failed along the back of the number 7 closest to the fire wall. That entire side kicked into the cooling ports( about 1/2 the fire ring kick out on the last blow). Im using studs, and I torque them with a beam type wrench. I have had the same studs for a few years..
Can you post some high-res pics of the gaskets. Not too tough to diagnose when you can see the gasket.

Lots of talk on head gaskets, torquing, torque to angle, etc., in Advanced Tech. Lots of views... very little response...

-Mindgame
Old Aug 6, 2004 | 08:30 PM
  #15  
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Re: LT1 head gaskets

So far I've had good luck with the fel-pros, and ARP studs.



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