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Rb26/rb30 Head Block Is Removed During Drag Race


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Dears,

I have problem with head block, it's always opening after drag race (2 runs or 3 runs), I changed the head bolts from RB25DET ARP bolts to RB26DET ARP bolts but still the same, The Head block is removed from the block after 2 runs or 3 runs, also I changed the Head but still the same.

Please see the following is my car engine info:

Horse Power: 1380

RB26 Head with RB30 Block

Cometic Head Gasket Kit – RB26DET - Thickness: 1.3m

RB30 CP Pistons 87m with 8.0 compression ratio

250HP Nitrous

RB26 ARP Head bolts (I tighted the head with more torque)

I don't know what to do?????

Please this is for those who reached 1300HP and above.

Thanks!

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Hey mate,

I think your block may be warped to some extent.

I recommend you pull it down and have it X rayed and then decked. X raying the block will show you if the problem will simply reoccur with time. If the block is bowed it is likely that the bow is formed deep into the casting and will just continue to warp its form over and over with time.

It would take some serious heat to cause such damage.

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i do remember hearing something about big hp VL rb30's running 1/2 inch chev head studs?? might be worth the research. but definately take gtscott's advise and thoroughly check the block. it may be worth investing in a billet block if ur chasing those numbers.

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Thank you for your replies.

I am running with 3.3 bars.

I don't know why the head is moving (Head lift: best translation)

My torque sequence is:

30 ft

55 ft

75 ft

125ft

I heard that HKS has special head gasket for 3 bars boost or more.

I think the problem is with head gasket, maybe I have to use another brand. (I am using Cometic head gasket)

Edited by Skyline-r
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my freind was running a VR4 block and was usnig nitrous with a cometic gasket and was starting the lift the head and seep through the gasket, they removed it and fitted a HKS unit i belive and was fine with no leaking i think they went a bit high settings on the head studs as well, but seemed to be the cometic gasket anway just what i saw might be the same if not the block being warped is a possiblity

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3.3 bar, obviously at this boost level the head is lifting causing the gasket to move/blow. Any gasket will blow if the head isnt secured. Is it blowing in the same spots? Does it blow if you turn the boost down?

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<BR>May be the Nitto drag gasket or this type of cometic gasket <BR><A class=bbc_url title="External link" href="http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=170265148970&ssPageName=STRK:MEWAX:IT" rel="nofollow external">http://cgi.ebay.com....e=STRK:MEWAX:IT</A><BR>
<BR><BR><BR>what is the different between this head gasket and Cometic normal gasket? is this comes with rings? (as per the picture) or it's special metal? Edited by Skyline-r
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my freind was running a VR4 block and was usnig nitrous with a cometic gasket and was starting the lift the head and seep through the gasket, they removed it and fitted a HKS unit i belive and was fine with no leaking i think they went a bit high settings on the head studs as well, but seemed to be the cometic gasket anway just what i saw might be the same if not the block being warped is a possiblity

How much Horse power did he reach and boost?

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