What should I do next to hold the head on

[Gareth87]

Had my rig on Matt's dyno at PITS the other day. After a few years between tunes I added a few sensors and swapped intercoolers. Result. 553hp at 26psi. Not bad for an FJ20 that was built in 2007.

The problem..

It filled the overflow bottle on hard runs which leads me to believe the head gasket isn't sealing.

I have a coolant pressure sensor which was reading cap pressure at 22psi and occasionally overrunning to 23/24 psi on deceleration after a pull. It was not spiking.

It has arp2000 head studs and a cometic gasket.

As its been 18 years in service, I pulled the engine out and head off. Everything looks good but we obviously have an issue.

Where I'm at..

Years ago I had the same issue, I checked the stud tension and they were all over the place. Some at 60 to 70 and some up near 90. I nipped them all to 100ft lbs and this stopped the water push until now. I believe this compromised the gasket back then.

What do I do?

2 options are.. 

1) I bought arp 625+s, which I could put in with a new gasket. Thinking Kameari this time, reassemble and try again.

2) strip the block, get fire rings machined in with copper gasket and try that.

I do not want to push it more than 28 to 30psi. I think the turbo will be out by then anyway. (G30-770).

My other concern is the long term ability of a copper head gasket. Are they streetable for years?

I feel like a new gasket with the new studs will probably suffice, but I don't know.

Any thoughts welcome and advice on copper gaskets and fire rings.

Thanks!

[MBS206]

When you pulled it off, there is no signs of blown head gasket?
Is it possible you have some other issues going on? Possible cracked blocked?

Or do you think it's straight up lifting the head?

Did you check what the head was torqued to before pulling it down (To see if possibly they're stretching, or starting to break threads out etc)?

[Gareth87]

3 hours ago, MBS206 said:

When you pulled it off, there is no signs of blown head gasket?
Is it possible you have some other issues going on? Possible cracked blocked?

Or do you think it's straight up lifting the head?

Did you check what the head was torqued to before pulling it down (To see if possibly they're stretching, or starting to break threads out etc)?

I can see between the water jacket and cyl 3 there wasn't a hard line of combustion gas. It certainly appears that the issue is coming from there.

Yes, checked the tension. All at 100ft lbs where I set them 5 years ago. These blocks can crack but generally when they have been over bored. Mine is only 0.5mm oversize at 89.5mm. They break between cylinders around the 91mm mark. No sign of that with mine.

My gut feeling is the head gasket lifted a while back when the studs stretched and i bandaided it by retorquing the studs. It's finally let go.