Anyone on hear using ether 2 head gaskets or a modified metal head gasket made from the parts of two gaskets.
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I know someone who made 1 cometic gasket out of 2 to dry and drop the c/r on their big power Vauxhall.
It didn't work but then they were asking a lot of it for it to work.
What are you trying to achieve exactly ? -
you have to use rs2 type metal gasket not 2 fibre ones
its pretty simple really...remove the top and bottom from 1 gasket then put them in the middle of the other gasket....mrc told me howComment
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so instead of 3 layers you have 5 layers?
its not simply one trimetallic gasket on top of the other ie 6 layers?Comment
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not sure on the number of layers from memory but i know the top and bottom are removed as i have them here...Comment
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so hang on,
if you havent used the top and bottom from one set, then that means that you only used the middle to add to the second set. So in total you have a 4 layered gasket set.Comment
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from memory i think the standard gasket has 5 layers,remove 2 from the other and you have 8 layers in total
in the middle of the gasket is a thicker layer,you end up with 2 of these in the finished oneComment
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I have taken my old gasket apart and there are four parts to it, the two outer layers are coated with a thin black rubber ,I assume to help the seal, and there are two inner layers, one metal layer is about 1 mm thick, then a very thin layer of a chrome like metal.
I have to say the gasket has been compressed so it could be that there are five and two have stuck together,so I wonder if there is a coating of some disscripton to help the middle layers to seal.Comment
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the 2 outer layers have a coating to help them stick to the purous head and block..hence why you remove them from the other gasket..you are correct that the middle layer has a thick metal shim and a thinner one coated...you will end up with 2 sets of these in 1 gasket
the middle sections will seal with the compression of the head to block,so no sealant requiredComment
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How long have you been useing this gasket,and with which head bolts,arp or ome.the 2 outer layers have a coating to help them stick to the purous head and block..hence why you remove them from the other gasket..you are correct that the middle layer has a thick metal shim and a thinner one coated...you will end up with 2 sets of these in 1 gasket
the middle sections will seal with the compression of the head to block,so no sealant requiredComment
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for over 2 years now..i would use arp.s to get a bit more"CLAMP DOWN"Comment
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something to bear in mind..stacking gaskets is great and cheap way to lower cr but if you stack gaskets you will lose some of the "quench" unless you run more radical duration/lift cams.
if you are getting detonation stacking gaskets can help very little or sometimes not at all and can result in hotspots and burning pistons/valves etc if pushed too far in the wrong conditions.
If you are only pushing it mildly it may be ok but I wouldnt want to go too mad with stacked gaskets.
I know JP has been succesful with his monster with stacked gaskets but you'll need to hear it from him if he has stuck to clearances and what head/cams combos trickery hes run\running to get away with it.
a quick google threw this read up...
Volcano ABY coupe
AntComment
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The resons for lowering cr as as follows,The head needs a very light skim to clean it up,and it is borderline now with a measurement through the bolt holes of 117.9mm.
I also want to clean the block which will remove more metal.I am concerned that this will make the CR to high,I am also concerned that the valve to piston gap will be to close,I cannot calculate this as I dont no the original dimmention through the bolt holes on a 3b head when new.
The block has been bored first oversize maule pistons which will have a small affect on lowering the CR
but my main concern is the piston to valve gap, a new metal head gasket is 1.65mm so the two middle layers are around 1mm, this would lower the cr by around 1point and should put the cr back to a little less than standard and also increase the the valve to piston gap.
The car is running full RS2 set up with 3inch turbo back ss and 7a exhuast cam.
far as the cams are concerned I was thinking of useing a 7a exhaust cam with standard 3b inlet,Comment
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Drill through the rivets and take the two central layers out. Place these ontop of the two layers from the secondbheadgasket placing them inside the outer layers of one of the two gaskets.
You will end up with a 6layer gasket and throwing away one upper and lower outer.
I ran clocked 7A cams with ported head at 30-32psi as a daily with ARP's on a GT30R making 528hp details of the engine is in the beginning of my bugswatter build thread.UrS6 Stroker + HTA3586 =
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does anyone know if a 7A head is identical in height as the ADU one? I know that the higher compression ration on the 7A engine is created by the pistons alone, not the head height,right?
So if the head is skimmed for evenness and this has never been done before, it should still be within specs with OEM rs2 cams, right?Comment
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