Head Stud Torque, Pushing Coolant @ 600Hp

[GTRNUR]

After some SAU searching, looks like I have the same issue on a completely stock RB25 with 23psi going through the motor.

Was at Wakefield yesterday and after the 4th session noticed my overflow was spewing out water however the water temps never went past 95 degrees. Straight away knew the head was lifting, dropped the boost a little down to 18psi and it seem to be ok. Car probably saw about 9 sessions with each being driven hard - still manage to drive the car home in one piece.

So now a question, can I just simply just try re-torque the head down without removing anything and just hope that it won't lift the head? I'm trying not to spend any money on the motor at all as I'm pretty happy with the power/response etc. (money to be spent on suspension instead).

If its a standard head gasket you may have already damaged the fire ring beyond where it will seal again. A burnt fire ring and carbon deposited on the seal surface will be the end of a good seal fore sure, regardless of clamping pressure achieved with ARP2000 head studs.

If the head has been off before and its now running a metal shim gasket, then thats a whole other can of worms which has thouraghly been discussed here already.

Yes you can access head bolts without pulling the cams out. I recommend getting a telescopic magnet to allow you to retrieve the bolts easier.

[Dose Pipe Sutututu]

sigh....

weighing up options now:

1. Be sensible and run less boost
2. Be a tight wad and apply more torque to factory studs
3. Just replace with ARP headstuds
4. New motor

[SimonR32]

If the head hadn't already lifted I would say to try replacing with ARP's one at a time, but as it is now too late, there is a good chance the gasket is damaged.

Depends really, mine sprayed some coolant into the overflow on the dyno at 7000rpm. We pulled it off the dyno and chucked ARP2000 studs in one by one the next day and it's been going for about 2 years since then. That's also running 550kw at the hubs and 2.1bar so not exactly friendly.

In terms of cams, if they have a recess you won't have to take them out, if they don't you will... It's not the hardest job, I'm no mechanic and it took me less than 4 hours

[scotty nm35]

New gasket and ARP's.

Now you have found the pressure limits of the stock motor, you will know how far you can push other rb's before a similar thing happens.

[Missileman]

sigh....

weighing up options now:

1. Be sensible and run less boost
2. Be a tight wad and apply more torque to factory studs
3. Just replace with ARP headstuds
4. New motor

New head gasket, stud kit, a box of beer for you and your helper, all done in one day? Why new motor?

[Dose Pipe Sutututu]

RB25DET NEO seems economical hahaha....

Well it did hold up pretty good at 1.6bar, only started spewing coolant like after lunch. The rest of the afternoon, kept it running at 1.3bar and my mate actually did 12 laps with the car and came back with still same amount of coolant.

So I'm hoping there wasn't too "much" damage done.

Good science experiment for me hahaha...

[Dose Pipe Sutututu]

New head gasket, stud kit, a box of beer for you and your helper, all done in one day? Why new motor?

I was thinking an used RB25DET NEO motor.. those things are fantastic, makes 400kW without a sweat.

[scotty nm35]

I was thinking an used RB25DET NEO motor.. those things are fantastic, makes 400kW without a sweat.

*Until you get it hot at the track.

[Missileman]

Fcuk it then, just get the stud kit torque it down, wind the boost up skids and grins. If it still leaks get the neo and install you used once ARP kit

[iruvyouskyrine]

I lifted the head in my neo and still did 2 drift days like that running 21psi and the temp gauge was over 125 as that was all my gauge would read. I really was absolutely ruthless with that engine and it took it like a champ.

[Dose Pipe Sutututu]

sounds like a plan, because I'm not making stupid power with this car is it worth getting the ARP2000 instead of the normal ARP?

Just to confirm, neither of the ARP or ARP2000 studs require retapping the block? (yes I've searched, but just to be sure).

[r32-25t]

You can't retension the factory skyline head bolts as they are torqued to yield, so just replace them with studs one at a time and hope for the best

[JH32]

You can't retension the factory skyline head bolts as they are torqued to yield, so just replace them with studs one at a time and hope for the best

What's the procedure for doing this? I mean, do you just do it as if you were bolting the head down for the first time i.e. follow the regular ARP installation procedure with respect to the pattern of studs installed and the torque applied?

[Blackkers]

If you leave all the other bolts in it probably won't matter which order they're replaced in.

Having said that, I'd follow the order arp specifies for the peace of mind.

[r32-25t]

Personally I do it in order of tensioning and to ARPs torque specs

[Dose Pipe Sutututu]

alright, will be doing that before the next track day

Thanks for everyone's help...

Last one, ARP or ARP2000?

[89CAL]

I would say whatever you can afford. Arp2000's may be a bit overkill but it never hurts to over engineer