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standard head gasket vs copper

cohn

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I have a RB30ET which i just rebuuilt the motor on replacing the original gasket with a copper head gasket and it is mixing oil with coolant in the motor so i am saying it's leaking through the head gasket.
I followed the torque specs in the gregories book, is this only suspose to be for the standard gaskets, is there a different torque spec/ sequence for a copper head gasket?
Does anyone know the exact procedure and specs for each gasket?
What is the boost limits for each gasket?
I will be running 1 bar or 14.7 psi of boost.

Thanks.
Colin.
 

mag

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I have a RB30ET which i just rebuuilt the motor on replacing the original gasket with a copper head gasket and it is mixing oil with coolant in the motor so i am saying it's leaking through the head gasket.
I followed the torque specs in the gregories book, is this only suspose to be for the standard gaskets, is there a different torque spec/ sequence for a copper head gasket?
Does anyone know the exact procedure and specs for each gasket?
What is the boost limits for each gasket?
I will be running 1 bar or 14.7 psi of boost.

Thanks.
Colin.

What no one knows..:whistling
 

Daza

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I cant help you with the boost limits of the different gaskets, but you would normally only use a copper gasket if you were removing the head often or just couldnt get the original gasket.
Did you use anything on the gasket faces?
Does the head block face use any O ring type seals? (Im not familiar with this motor)
Did the head pressure test OK? It may have an internal leak from one of the oil galleries.
I have found a liberal spray of "Hylomar" it helps them stick/seal a lot better. If it's a new copper gasket retension it after the first heat cycle (I normally do it when it's hot radiator cap never fitted). Then retension at 500km's that should do it. Use the reccomended tension and sequence as the bolts and decks are normally the limiting factor. You can use other stuff as long as its not in contact with the flame front normally only around oil/water galleries (Avation gasket cement 4 this will make the head difficult to remove though). Back in the stone age silver frost paint was also used on gasket faces.
Good Luck
Daza
 

ucwepn

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Copper head gaskets are generally used on higher compression motors to lower the compression so that more boost can be run I.E- non turbo to turbo conversions. Are you sure its not a steel gasket? You should get in touch with a good performance shop that has experience with rb30's and they will know whats up with the tensioning for different material gaskets etc.
 

Bax

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I'd say that 99 out of 100 people will recommend you the genuine Nissan gasket, I'm fairly sure I told you this in the original thread that you created. And I stand by it.

However, as far as your gasket goes, as has been said above a liberal coating of another gasket putty/ sealant along with the gasket should get yourself a good seal. As far as doing the bolts up the sequence will always be the same, its that way to get equal pressure across all parts of the head.

Did you re-torque the bolts after 500 km's or so? Every gasket is meant to shrink a bit with heat, once it has reduced you are meant to re-torque all the bolts to take up the slack from the reduction in size, same goes for exhaust and inlet manifold gaskets.
 

Tree cutter

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Are you sure it is a gasket problem and not a cracked head. RB30 heads have been known to crack from front to rear along the camshaft bearing journals. You might have a small crack that is hard to see.
 

cohn

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the head had a crack but thats been fixed when i did the head, and its been cracked tested.
re-torque? do you mean just go over the bolts, or loosen then tighten again, and hot or cold motor?
 

Bax

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re-torque, you'd have to tighten them again, as far as hot/cold motor goes i'm not sure, presumably cold but you'd have to ask your mechanic or somebody local about that.
 

Daza

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Im my experience with copper head gaskets they expand a little and anneal on the first heat cycle thats why I retension them when hot on the first cycle. In my opinion they are not ideal for anything with a iron alloy face as the expansion rates differ to much. If you are using the copper to get a thicker gasket to decompress thats allways a risk.
Hylomar when applied correctly is good gear, I defy anyone to fit a head gasket to a 265 and seal it without using this stuff.
Cheers
Daza
 

BLOWN-VP

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some copper head gaskets are already annealed heat cycled when you buy them.on my blown vp i used three bond sealant on the copper head gaskets.also heads are o ringed.tightened standard head bolts to factory specs.loosened slightly and re tightened.no problems.running 10 psi boost whipple charger.
cheers darren.
 
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