Jump to content
SAU Community

Recommended Posts

question for the engine builders and knowledgable..

just recently brought a GTR with built RB28, first time we put it on the dyno it split a wastegate hose and hit boost cut at over 30psi, now there is a tiny oil leak under the exhaust manifold between the head and block, been told its probibly stretched the head studs and we need to remove head to replace studs and get head checked etc etc

Excuse my ignorance for knowing f### all, but can't the head just be re-torqued ???? car still runs perfectly

If the above is needed, how would I expect to pay ?

Link to comment
https://www.sau.com.au/forums/topic/320996-stretch-head-studs/
Share on other sites

I'm no engine builder, but you'd want your head studs to be as top spec as possible. They're not THAT expensive, after all you don't want be cruising down the road and pop a head gasket, then have to fork out more to rip the head off, just cos you skimped out on the studs...

I say if they are in anyway damaged at all, replace them. Who knows, they might just need re-torquing, but i doubt it if the head has lifted enough to cause a leak. I'm surprised you didn't damage the bottom end at all, if boost was that high, how didn't you get heaps of detonation and end up with killed pistons?

Sorry to answer a question with a question, but why wasn't the boost monitored? i.e. surely the tuner saw that the boost was increasing out of sight, why didn't he stop the run when boost was spiking out of control?

Excuse my ignorance for knowing f### all,

Don't apologize man! That's what this forum's about!

just got off the phone from the workshop, after a more thorough inspection they are leaning towards a wrongly machined block or head , slightly to much removed on the outside of the oil gallery that feeds the head....only the smallest leak atm, not to many options with this one, not far off a full rebuild, pretty piss poor, engine has done less than 5000km and cost the previous owner over $50k

we're going to try chemi-weld or something similar as a patch, ( because I only just bought the car and can't afford a rebuild straight away :)

very pissed off

What turbo/s?

HKS step2 2.8 stroker, full counter crank and rods kit, CP pistons.

Brand new head from Nissan, Jun 272 in and ex cams, 10.8mm(?) lift, special retainers and all the jazz needed to support the cams and high revs, heads extensively ported.

Big dollar hypertune plenum and single throttle body setup

Custom alloy breather tank etc

Jun oil pump, N1 water pump, cant recall the brand of balancer, but its a good one.

Trust sump extension.

Turbonetics GTK-850 turbo and big Turbonetics external gate

What head gasket, MLS or copper ?...i have seen copper head gaskets needing a re-torque.

You shouldnt see this normally with a good mls though.

I'm not sure, I'll be ring the mechanic who built it tomorrow, I would think judging by the rest of the build, it would be a good one, doesn't appear to have skimped anywhere else..

The whole thing souds like a bit of a crock from the info you have provided.

Not from you personally but from the 'workshop'.

Stands out like dogs nuts...can't understand why the king of RB engineering ^ didn't pick it up instantly.

I build these engines all the time and i have a fair idea what has happened. Was it built locally?

Edited by Swiper the Fox
The whole thing souds like a bit of a crock from the info you have provided.

Not from you personally but from the 'workshop'.

Stands out like dogs nuts...can't understand why the king of RB engineering ^ didn't pick it up instantly.

I build these engines all the time and i have a fair idea what has happened. Was it built locally?

it was built in adelaide , I'm in perth..

please elaborate on whats happened

it was built in adelaide , I'm in perth..

please elaborate on whats happened

Ok..for a start there are NO oil feeds to the head on the exhaust side of the engine...so that statement they made to you is incorrect.

It was built using a fastner when correctly installed that can generate a maximum clamping force of 220,000psi under operating conditions below its yield strength.

The engine only saw 30psi of boost!...stretching a 12mm main stud takes a bit more than that.

My guess is one of these...incorrectly installed stud...probably bottomed out or incorrectly torqued , poorly cleaned head that has leaked oil onto the head gasket during installation compromising the seal or the block is split around the turbo oil feed.

Ok..for a start there are NO oil feeds to the head on the exhaust side of the engine...so that statement they made to you is incorrect.

It was built using a fastner when correctly installed that can generate a maximum clamping force of 220,000psi under operating conditions below its yield strength.

The engine only saw 30psi of boost!...stretching a 12mm main stud takes a bit more than that.

My guess is one of these...incorrectly installed stud...probably bottomed out or incorrectly torqued , poorly cleaned head that has leaked oil onto the head gasket during installation compromising the seal or the block is split around the turbo oil feed.

thanks for your help..althou none of those options sound good ..

cheers

thanks for your help..althou none of those options sound good ..

cheers

just something to compare...i knocked up an engine from mostly used parts for my wife so she had a decent engine to race at the drags. It had 2nd hand Nissan head bolts and stock head gasket...

It was thrashed for over 3 years and won about a dozen trophys and made 465+awkw at around 35psi of boost!

Id never recommend anyone ever actually do this but it goes to show it not the sum of the parts used...its how they are put together that really counts the most.

just something to compare...i knocked up an engine from mostly used parts for my wife so she had a decent engine to race at the drags. It had 2nd hand Nissan head bolts and stock head gasket...

It was thrashed for over 3 years and won about a dozen trophys and made 465+awkw at around 35psi of boost!

Id never recommend anyone ever actually do this but it goes to show it not the sum of the parts used...its how they are put together that really counts the most.

boy aint that the truth

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • What an awesome idea to fit the facelift Lamborghini Diablo headlights. They are a perfect fit!
    • An update regarding the registration with the DVLA I sent off the paperwork the day after I collected the car from the port, two weeks later it was all returned with a letter explaining they have rejected the application. This was because the cheque was £20 short for the road tax (I used a price list I found online). Nevermind it is what it is, it was sent back to them the following day with a new cheque. Fast forward another 2 weeks or so, I called them for an update to be told it had been rejected. Yesterday (16th September) I received the documents back along with another letter, this time it was because I didn't put an X in one box on the V750 (personalised number plate certificate), which declared that I had the rights to the personalised number plate. Why this wasn't mentioned in the first rejection letter, I don't know, but it could have saved this headache. The documents were sent back today, so fingers crossed third times a charm and it'll FINALLY be registered on the road just in time for the bad weather (woohoo!) To cheer myself up I lowered the front 25mm, was sick of seeing it sit like a monster truck. No idea how much clearance I'll have getting on and off the driveway, I'll worry about that when I can actually drive it
    • You're going to miss not worrying about rust in the strut towers like the Skyline shitboxes out there
    • A few little updates that weren't filmed due to not taking long to do or not interesting enough for their own video. My new K&N Air Filter arrived, I went with an RU-4180 which matched the dimensions of the universal cone filter the car originally had.  The battery had gone flat, while that was charging I tidied up the spaghetti wiring at the bulk head and down the sides of the engine Next job was to swap the stereo The Kenwood harness had the female ISO plugs cut off and the male ISO plugs cut off the adaptor loom and joined with bullet connectors. I ordered in a repair loom through work and re-did it all. New Kenwood unit installed (Android Auto, DAB, Bluetooth, Reverse Camera) The bonnet/hood gas struts have been poor since collecting the car. I couldn't find any suitable replacements locally so took a chance on a pair from AliExpress.  The originals don't use a retaining clip to secure the cup onto the ball fixture, would explain why I struggled for 10-15mins trying to pry off the cups. The ball fixtures unscrew using a 12mm spanner, new ones are the same size. Sadly no photo of them fitted, you're not missing much lol The dished Momo steering wheel got replaced with my Momo Tuner, turns out I ordered counter sunk bolts for the horn trim ring (like they normally are for the steering wheel) instead of allen cap (flat seat)  A terrible photo of a Quaife style gear shift knob I've had stashed in my tool box for many years after purchasing the incorrect thread size (I can see a pattern emerging with ordering incorrect parts...) Also threw in a cup holder and a (empty) Boss Coffee can, because why not  
    • GT-R clearly the better choice! The 300 is certainly not insaly fast but has a decent amount of poke. Does a nice little drift around the corners with a decent amount of throttle. It's VERY predictable in a slide too.  Feels so progressive! People probably presume there's a 25 year old driving it based on my behaviour this week! 🤣
×
×
  • Create New...