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How can you diagnoise whether you have a spun earing or not, or whether the oil pump has gone bang?, my gasket blew, but it wasnt because ov over-revving, but none the less im trying to diagnose the fault....My car still was running when the gasket blew so hopefully i havent done damage to the bottom end...i also had oil in the sytem(just milky oil)....ive opened up the head anyhow, so is there anyway i can tell if my oil pump is shot w/o opening the block?

Would it be better to have it tuned to say 7000/7500rpm, either way i dont think theres much power to be made after 7000 on a stock gtr....

Hey guys, im getting my motor rebuilt at the moment, back to factory specs, car already has acl pistons -.5mm oversize, larger turbos, everything else stock, bar arc panel filter plus cold air box, and exhaust....what is the safe limit for the rb26std when it comes to revs, ive heard ~7000rpm?, others seem to also believe that the stock gauge is always off by around 400rpm? thanks- ive tried searching about this with no luck....just want to know others thoughts

Hey thanks alot mate:), one think i can tell you is the head bolts were torqued over 110ft/lbs, definitely not factory (could over torque settings also cause this?), thanks for clarifying the pistons mate:).If they are .5mm oversize, then the bore should be ~86.5mm, in which case an 87mm gasket will be fine right??? Yip the gasket was blown mate, all the signs were there, my car started to white smoke excessively, and the smell was acidic, checked the oil and it was all milky, no water in coolant..... car would start after a period of time once the gasket was bad, but i only ever cranked it over once then got it towed back home.I can see it being anything else....i was thinking it may have been bearing and oil pump, but my car still was starting and oil was still there. - does the block need to be out for it to be checked to see if it's flat, as the heads already out, my concern was why no.6 piston was hitting the squish pads on the head, and the others werent, and whether or not its safe to weld the squish pads back for no.6 bore on the head and resurface and assemble back?, it doesnt seem like a major, and the pistons look all ok. thanks in advice:)

Just on a side note - this was not a built engine or nothing, it was just a stock motor with rebuilt internals (headwork and forged pistons etc...), and the gasket went and this is what occured, what worries me is this happened less than 15k after it had been rebuilt.

Hey guys, im putting my head back together soon, and replaced the head studs for arp ones....what torque settings should i use (same as manual says)??? or should i torque them slightly higher for the arp studs?...thanks - its for an rb26

I've attached a couple of pics as mentioned earlier. If you have a look at the first picture, youll notice how no.6 piston got damaged whilst the others hadnt at all. Basically check out the circle i highlighted in red (the good piston), and compare it to the piston beside it, and in that squish area highlighted in blue....notice how theres no meat left in that squish area on the piston on the right (no.6)?, its the same on the head side of things (sorry the head is at a workshop so couldt take any photos), but basically the head looked fine apart from the squish area on the no.6 bore on the head which was geting hit at, hard to explain, but it seems odd that it was only no 6, thus the reason why i think the pistons arent actually touching the head like i 1st thought since the other 5 cylinder bores are fine opn the head itself. The 2nd pic ive attached is the piston head, and was wondering if anyone can shed some more light on what type of pistons these are just by looking at them, and whether or not they can tell me how oversize they are etc.... thanks!

Thanks, ve posted a new thread about the squish area...basically it was only piston no.6 that was hitting the squish on the head...very odd as to why this has happened, but it was no.6 piston that let go thus causing the gasket to blow so it kind of makes sense...

Sorry i dont, its really wierd though that only no.6 hit the head itself, whilst others didnt, though it was noticeable as piston no6 had skimmed a certain part of the piston whilst the others had no sign of it even touching or melting away....ill post up some pics later on today .... could it be the no 6 piston is more vunerable to having this happen?or that the rods/pistons werent assembled correctly for something like this to occur in the first place....maybe revs were kept too high?? thanks.

Hehe - no not a fun job at all.....we manage to pull the head off without having to pull off the turbos luckily enough, we removed the exh manifold studs, raised the head upwards, removed the manifold to turbo end from their studs, and then pulled the manifold out - what a job i tell you, mind you 2nd time around itll be much easier:)..... Cooling in no.6...how can i overcome this?

Thanks makes alot more sense now, so is this an engine out job to do?, ie will i have to remove the block aswell, and calculate how much thou needs to be taken off the squish area???? or is there a baseline of say 30/40 thou take off the squish to accomodate for high rpm piston stretch?.....would it be a good idea to see if the pistons are already protruding over the block bore first?or will this only occur at extreem rpm's? im just a bit stumpt by the fact that only no.6 took the hit with the squish and got the hammering whilst all the others were fine (no.6 cylinder was the culprit for the gasket blow though....) Thanks in advice.

Hey guys, i thought id start a new topic after having not much information on the rb26 head squish/quench areas(ive attached a picture to show what i mean). I just pulled off the head on my rb26 engine to find that no.6 chamber got the worst treatment from the cylinders, and from the oxidation - it looks like it chewed through the no.6 bore on head squish/quench area with the help of detonation most likely, the other cylinders were well of and had no real signs of the squish areas being taken off at all.... It was no.6 cylinder that had the most coolant in it when we pulled off the head so it kind of makes sense.... The car was rebuilt not long ago at all, and i suspect having seen the block had been bored out, it was fitted with oversized pistons, and it seems alot of people on the forums skim some of these quench or squish areas of the head to firther limit engine detonation and so forth?....ive even seen where its been removed altogether to stop it altogether, whilst others remove the exhaust side only, and skim the inlet size. I need to know the pros, and cons of doing this when talking to my specialists, and whether or not its worthwhile to see if my pistons protrude or not while the block is open?...can i work out how much to remove from the squish/quench area depending on piston protrusion? thanks in advice

on further research, ive noticed alot of people remove the squish area on the head...which is the area where the pistons seemed to have been touching the head itself, no 6 got the worst damge, and the others had minimal, but were nticeable....i was thinking that since the water was chewing away at no.6 it wouldve made things worst than it looks....

Thanks mate, so basically the block also needs to be given to the engine recon'ers to have them figure out whats happened?as the head is already with them.

Thanks guys, head is off, and big problem, it looks like whoever rebuilt the motor last done it all wrong!, the pistons appear to be hitting the head, and that was confirmed once i showed the reconditioners the head, the block may need to be taken out, but maybe not if the pistons can be removed and re-shimmed to clear the gap..... What's the best idea from here people?the cylinders have been bored out, dnno how much too though as i didn't have a vernia dial at the time, but i could see the sleeving.... I hear the stock rb26 headgasket is 0.9mm in size?, if my cylinder have been bored out, and the head gets machined, would 1mm headgasket thickness still be ok?or would i be pushing it.... Have alot of work still to do, here i was thinking im all done!...

Hahah im in the same boat, just going bit by bit trying to figure it all out one by one - not that hard so long as i make sure i do i go by manual - and do it all by the book i guess.....timing belt may be something ill take my time to do. thanks.

Thanks abobob:) much appreciated! - just a few questions, would it be ok to get a 87mm headgasket(as 86 is rear with aftermarket stuff) if my bore size is still stock 86mm?..... Now i know the bore size from stock, im thinking of going 1.2mm headgasket....if my cylinders have been bored to 87mm (i think i have some wiseco istons in there already, will find out tommorow), will 1.2mm gasket make me reasonably close to stock compression anyhow, maybe even higher, as long as its safe im happy, asnd yes 300-350awkw on smaller gtss turbos are the plan, response is a must:) thanks - the cams i want are the tomei straight bolt on ones, if i do get cam gears aswell, do i need a tune, as i have no $$$ for that right now, and only enough to buy the cams and gears and have them fitted to factory ecu and very little mods.... thanks.

Thanks for the advice, ill get onto removing the turbos tommorow - just wanted to know if there were other ways around it, should take any longer than an hour tops now maybe two....

Head nearly off - intake side all done, just oding the last bits of the exh side tommorow - do the turbos need to come off to remove the head?, or could we get away with removing the exh manifolds from the turbos and leave the turbos intact? Also, i had a very hard time with the Oil/water feed lines on the exh side, as whoever tightened the nuts last, done them extremely tight!!!, we ended up having to pull the whole feed out from around the back of the head....in the process the lines had bent abit, but i assume we can bend them back into shape and all is ok? other than that no real dramas. Thanks.

Hey - the tomei head gasket kit comes with a oil restrictor gallery orifice.....is this something that the specialists needs to do when dissembling the head - or something that i could do myself when putting the mototr back together once the heads been tested/repaired?

Thanks:), manage to do half of it today - will be finishing the second half tommorow, and get it taken to specialists to check the head for cracks, warped head etc.... Can i check the bore size using like a vernadial? - so basically .5mm difference in gasket size is alright to do(so long as it's .5mm increase?), and do i need to seal the gasket with anything, ive been searching the forums, alot of people say metal head gaskets don't need to be sealed with any sort of sealant, others reccomend it be done.... P.S: I have wiseco pistons already (as per the rebuild notes - i will confirm this tommorow when head is apart though)... Question ive been dying to ask, and one that i had removed not so long ago when posting a thread(even though io searched alot of times).... What is the stock rb26 compression ratio and gasket thickness?.... And why would i go say 1.2mm over say 1mm? - for a car aiming not for high hp, but street response and around the 300awkw-320awkw maybe down the line max...what compression ratio would suit?. Either way im really thinking of going the 1.2mm route now anyways, after searching miliions of threads on this topic:) Thanks for all the help!

Hey guys, im going to be replacing my headgasket for a tomie metal head gasket(once i find out the bore size)....all i want to know is stock rb26 bore size, and stock compression. I'd also like to know what size thickness headgasket you go to when upgrading, and why - as im deciding whether to go 1mm or 1.2mm (im after 300-320awkw max using gt-ss turbos, for street, so response is crucial for me....) Thanks in advise

Mm...still deciding on what comp ratio i should go for on my rb26 motor....are cams easy to install - id like to do them as the engine is already open for it......do i need anything else to install the cams, as im after the tomei 260 9.15mm lift like alot of others here use...

Just an update - ill be doing the headwork removal tommorow:)

Thanks guys, like i said, ill have to open up to see what the bore size is first, bottom end was rebuilt with forged pistons already, and i dont have any $$$ to get anything else fitted to the bottom end right now, unless its easy to get to while the head is open - i see people running gt-ss turbo setup on stock internal gtr's with no issues either way. What's the std bore size on the rb26dett?, and from the receipts ive seen from the previous rebuild, there was a rebore that took place. When the head has been rebored, does that mean the compression goes up or down?, even when using the stock gasket? P.s theres varied opinions on headgaskets, some say 1mm and have more compression, others say 1.2mm.....which would be a safe bet with my 300-350rwkw target?for the street, mountain sprints....and reiability being key, as is response. The tomei kits come with an oil restrictor gallery orifice...what is this exactly?and is this something the bottom end needs to be opened for? It comes with new gaskets for inlet/exh manifolds aswell....i was thinking if i should replace these manifold studs aswell with oem nissan maybe? Sorry for all the questions guys, the head may be getting pulled out within the next few days and i would appreciate as much info as possible. So tomei 9.15mm lift cams are direct bolt up, and will just work?, do i need to adjust them at all??? Thanks.