Build N54 Headgasket problems advice please

Lowboost35

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May 21, 2022
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Hello guys long story short. N54 lift head gasket once on 17T FBO 550whp.

After that i go for build engine rods pistons , cutom exhaust manifold runing single turbo 8hp70 etc... lift head again at 600whp power range turns out that ARP heat studs pull a treath from cyl 6. New cylinder head now fully serviced drilled and tapped cyl 1 and 6 block for 11mm studs and its building pressure at cooling system at 1.8bar boost 640whp..... at low boost 1.2bar ant allot abuse its looks fine no pressure building in coolant system. For third time thinking to go back to ARP studs and athena HG. Any advice guys
 

RuskiRacer

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Jul 17, 2019
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Hello guys long story short. N54 lift head gasket once on 17T FBO 550whp.

After that i go for build engine rods pistons , cutom exhaust manifold runing single turbo 8hp70 etc... lift head again at 600whp power range turns out that ARP heat studs pull a treath from cyl 6. New cylinder head now fully serviced drilled and tapped cyl 1 and 6 block for 11mm studs and its building pressure at cooling system at 1.8bar boost 640whp..... at low boost 1.2bar ant allot abuse its looks fine no pressure building in coolant system. For third time thinking to go back to ARP studs and athena HG. Any advice guys
What head gasket are you using and what are you torquing the head down to and are you following the proper sequence? Only time I've ever lifted the head was at 23 psi on my 68mm and the head threads were already compromised
 

RuskiRacer

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Jul 17, 2019
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First I hear of head lifting at 550whp.
Curious if car was ran hard at 1/2 mile events or long pulls well into 5th and 6th gear ?
Shouldn't even be a problem. There must be an issue in the torque sequence or the torquing on the head gasket. Its well known that when done properly n54s don't really have head gasket issues. Bad tune up is a possibility as well
 
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Brule

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Feb 20, 2017
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They do just not many people log coolant pressure.
 

RuskiRacer

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Jul 17, 2019
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This 👆🏽👆🏽👆🏽👆🏽
BMW has a weird way of bleeding the N54.
Either way, 550whp should not lift a head on the N54 IMO.
Agreed , even stock head bolts should not be stretching that much at 550whp to show up in logs as coolant pressure
 
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Lowboost35

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May 21, 2022
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received_3064968340443260.jpeg
first Time lift head unopen engine. Second Time builds engine 9,5:CR arp studs Pull from cyl 6 , Third Time deside go with stock bolts all m11 including cyl 1 and 6 torque sequens was done right. Third Time also DI was deleted new maxxecu new tuner.
 
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RuskiRacer

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View attachment 68928first Time lift head unopen engine. Second Time builds engine 9,5:CR arp studs Pull from cyl 6 , Third Time deside go with stock bolts all m11 including cyl 1 and 6 torque sequens was done right. Third Time also DI was deleted new maxxecu new tuner.
Wait you went back to stock headbolts with ns300l inserts ?
 

STE92

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Mar 3, 2017
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Whats the torque # you are using on the ARPs? At those power levels you shouldn't be having issues. Makes me think that you either have severely warped decks or a hairline crack you aren't seeing.
 
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IQraceworks

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@Lowboost35

.....so what ever came of this? Did you find that you were torquing things wrong? What was the end result? I'm assuming something very wrong if you lifted a head at least three times, and sub 600hp levels....even with steel thread inserts and all 11mm studs.

Just wondering what you ended up figuring out.....
 

Lowboost35

New Member
May 21, 2022
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Conclusions with timeserts and all 11mm studs and Athena hg with fire rings fix the issue. But came another one hg leaks oil even after machined Surface, retorque after heat cycles , torque higher specs, all this 2x or 3 times with new gasket. Now we back to mls gasket , close deck block and studs by hcr. So far no problems last season at no prep track 9.3 1/4