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

    • Hi all, Restoring r33 series 1 rb25det. All the heater hoses were on their way out, have replaced them and put it all back together. After testing I noticed a small leak from behind the head on the actual metal water line to the turbo when cars warm. I tried running a longer hose over it but it kept leaking...   I am about to take the (stock) manifold off again😔 to change the water line does any one have any lines they recommend? I was looking at Aeroflow Turbo Oil & Water Line Set but not sure what everyone else recommends. Car is completely stock but want to upgrade turbo eventually. it looks like ill have to disconnect a lot just to replace these lines so if there's anything else recommended to do please let me know. Thank you in advance!
    • From memory, on the R33 GTSt at least, while everyone says "It's not adjustable", I found when I changed clutches in mine, it just needed a small adjustment on the rod length. But be very wary here, as you could end up trying to push the pushrod in the master too far, or blowing out the slave.   Most likely though, if the master/slave isn't bypassing internally or leaking out, then the throw out is the wrong height compared to the fingers on the clutch, so when it moves to disengage the clutch, it isn't 100% disengaged. You can check part of this out too by jacking the car up, having the engine running, put your foot on the clutch and try to engage 1st gear. If it goes in pretty easy (Compared to the ground) and/or the wheels start turning a fair bit and it takes a bit too much brake pedal to bring them back to a stop, this is likely the issue.  I'm not sure if you can adjust the height of the forks etc in these though, it's been that long since I've touched any RB gearbox.
    • That's all good, I thought I was missing some interesting feature! Maybe @PranK can double check if that is something that is meant to be operating or not.
    • I hope that is not something that bad. From what i remember he said that only first gear is "hard" to get in and that he has couple of ideas what to try next but idk 😕  hope it is not gearbox out. I will let you know.
    • If it's not the hydraulics, it is probably gearbox back out. Usually as per @Duncan's post, or otherwise associated with not getting the throwout fork positioned correctly. All the way up to catastrophically bolting shit back together without it being aligned properly and wrecking the clutch/input shaft/flywheel/something else.
×
×
  • Create New...