Build N54 Headgasket problems advice please

Lowboost35

New Member
May 21, 2022
2
0
0
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

Captain
Vendor
Jul 17, 2019
1,209
746
0
Ride
2009 e93 335i
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
 

SlowE93

Captain
Jul 2, 2017
1,390
1
762
0
Ride
E93
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 ?
 
  • Agree
Reactions: RuskiRacer

RuskiRacer

Captain
Vendor
Jul 17, 2019
1,209
746
0
Ride
2009 e93 335i
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
 
  • Like
Reactions: SlowE93

Brule

Sergeant
Feb 20, 2017
326
376
0
Ride
335i 2007 6spd manual
They do just not many people log coolant pressure.
 

RuskiRacer

Captain
Vendor
Jul 17, 2019
1,209
746
0
Ride
2009 e93 335i
I question if some people know how to bleed the cooling system properly
 

RuskiRacer

Captain
Vendor
Jul 17, 2019
1,209
746
0
Ride
2009 e93 335i
This πŸ‘†πŸ½πŸ‘†πŸ½πŸ‘†πŸ½πŸ‘†πŸ½
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
 
  • Like
Reactions: SlowE93

Lowboost35

New Member
May 21, 2022
2
0
0
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.
 
  • Wow
Reactions: doublespaces

RuskiRacer

Captain
Vendor
Jul 17, 2019
1,209
746
0
Ride
2009 e93 335i
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

Corporal
Mar 3, 2017
217
78
0
Ride
E92
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.
 
  • Agree
Reactions: RuskiRacer