TriniGT

Should I worry?

Okay so should I be worried about the four thou bore the machine shop gave me for piston to wall? He used the pistons when doing the honing. Let me know.

The machine shop said the CPs were one thou over the spec on the sheet unbelievably. He told me he gave clearance of 4 thou, wondering if I should be worried. I am going to be using the top 17, second 19 and oil as a recommended 16 just to be in between what was advised. Didn't think I would get help on this as I know people usually keep these things to themselves so thanks a lot. Will let you know how it goes and should I worry on the piston to bore clearance of four thou?

Thanks a lot measure three times and rebuild once. I will check all clearances and this block is a hones one, I will definitely check the bore at different positions to see if the bore is uniform and likewise for the rod bid end clearances and like you said write them down and number then to know everything is accounted for. Will let you know how it goes. Also what ring gaping you recommend for the different rings, I have read to leave the oil ring as it is but can you give me some insight on what clearances one each of the ring so I can get it right the first time. Thanks.

I am doing a fresh build and I wanna be sure on clearances. I know some people mostly shops will keep this to themselves but being that I am all the way over here and cannot send my engine to one of you'll competent builders maybe someone can give me an idea of what clearances to use. I have had the block decked and polished along with the crank and I am ready to check ring gapping and want to know what gapping to use on each ring, my power goal is somewhere around 500-600, not crossing 600. I want the build to be reliable and not losing oil due to big clearances. Can anyone advise me what is a safe gapping. This is a stock bored 86mm RB26 and I am using stock CP forgies with RB26 rods. Any help is greatly appreciated. Jason.

Did you put an oil restrictor in, not the one that so-call comes with the turbo built-in. For an added safety a ballbearing turbo should have a 0.035" restrictor in line fo the oil supply. For journal bearing turbos it should be 0.06". Also make sure that your oil return line from the turbo is not kinked and causing a backup of oil in the turbo as this can cause the selas to go eventually, if caught soon enough you should be okay just the turbo will need a little cleaning. Check it like now, any kink in the return is a no go, get a good braided return or a hard line that lines up perfect with the block so that the return hose is straight. Cheers .

Are there any issues running the external off the housing like that? I thought I read that there were boost issues?

Damn, I only get 240Km on a full tank on my GTT. It is a pretty stock setup with a few minor mods that came with it from Japan. Upgrades are mainly, Blitz ECU, Blitz EBC, Blitz Timer, HKS FMIC, Trust Air Filter and an HKS SSQV vented. When I got it I immediately changed oil and coolant and installed my defis to monitor everything, the car boost fine to redline and I do drive hard but not shifting on redline maybe around 6-6500rpm. I know the vented BOV is causing some bad consumption and I am also thinking that I should get a power FC as the Blitz ECU is not tuned for my octane level. So my next step is to get the power FC and change my plugs for some new NGK BKR7s gapped to 0.8mm and see if that helps. I am also going to be recirculating the BOV, clean my throttle and replace my stock intake pipe with a metal one and redo my intake manifold to face forward and reduce the intake cold pipe route same time. Hopefully after all this with a new tune my mileage should be better. We'll see.

From being on the forums I think DiRTgarage is as reputable as you can get .

Also getting a Twinscroll Exhaust Manifold and Turbo setup will help with spooling as well, if you are trying to get everything out of the setup, needless to say a good tune.

The URAS kit is for an R34 GTR or a 33? Willing to ship and also pics?

I dunno maybe put the RB26 individual throttles on the RB25 to give it better low down response.

Oh just confirmed yeah 300+ amp tig FTW. I just spoke with him and he said he has done a number of heads and has some tricks up his sleeve, hopefully things go according to plan, he also has his machine shop that will be flattening the intake side and then tapping them as well. We'll see how it goes, this week I will be doing some valve guide work. GTS4WD thanks for the tips and I will keep in touch with my findings and results .

Well I spoke to some people and got some more options but my friend that does the welding does a pretty decent job, this is the reason why I bought a scrapped head to do the job on in the even that it does fail then I still have my car running. Can anyone guide me as to how to remove the two stuck valves, should I just heat the area and tap the entire valve and guide out, I will need to replace all guides so I need some pointers on the difficulty of replacing the guides myself as finding good machinists locally is few and far between.

Why don't you make some copies? I can't see myself spitting out $2400 for it but it is a nice piece though. I am gonna try what I can on my spare head and see what can happen. Does anyone know how to go about removing two stuck valves, they are stuck shut, I am thinking maybe heating the head and removign the entire guide and vlave together, anyone has an idea what can be done, I don't want to be pounding on it hoping it pops free and damage something. All valves seals, springs, retainers, buckets etc have been removed along with valves except for these two valves, once removed I will get eerything welded and machined and tapped and then have the remaining guides removed and replaced and then have the entire head rebuilt. Also is it safe to drill and tap the exhaust side for the RB26 mani or should I just use the stock RB26 manis and have the appropriate flanges cut and flipped and rewelded, I have a good cast iron welder?

Well after all was said and done I took some advice and looking at a different plan, I still picked up the damaged RB26 and really it is the crank and block that are shot so I will be keeping the head as a spare along with some other parts and using the individual throttles for the Neo and I will also do a twin turbo setup just to be a little different. I am keeping the block stock for now and gonna get ARP headstuds, Cosworth Headgasket and as suggested the pon cams. The twin turbos that came with the damaged engine were R32 Nismos so I am gonna use them along with the 550 CC Nismo injectors and probably an HKs fuel Rail. I already found a scrapped Neo head so I will do all the work to that head and then swap over the necessary parts like the missing VCT and valves and a couple of valve springs that don't look to be in the best condition. Yeah I will also use the RB26 cam covers and also at the same time tap the back of the head for the oil return to the sump and put in the needed tomei restrictor in the head. Seeing that I have an N1 Oil Pump I will throw that in with new tensioner and Water Pump. I am not going to bother porting the head as it looks pretty nice already, just new gaskets and valve seals, reseat the valves and make sure everything is in tolerance. For sure I am also gonna have the guides changed as I found that one of the intake guides was cracked so I will have the shop replace all of them. Two quesitons, does anyone know if Neo and regular RB25DET head gasket kits are the same, one with the VCT that is, and also where can I get replacement guides from?

I got the buckets out so now it's time remove the springs and whatnot, gonna leave the guides in for now and have everything done then have them replaced. Gonna have the head submerged in water and have the intake side be above water for welding to hopefully eliminate any heat problems. Any updates on your side, I am doing R32 Nismo twin turbos and 550 Nismo injectors on the RB26 fuel rail. I am also not filling the intake ports but reshaping the individual throttle adapter to match the bigger RB25 Neo intakes, there should be more than enough that I can machine off comfortably. Quick question for later on down the road, has anyone run a blow through setup on the RB25 as I am thinking of running this with twin setup using a Q45 MAF, your thoughts?

I was lucky enough to pick up a Neo head today, it was scrapped missing the cams, cam caps, and RB25 cam covers and the VTC solenoid. I dropped off the entire intake side and looked everything over. The only thing I am concerned about is that I see two exhaust valves halfway open and they have the lifter and springs attached. The block was left open with no covers and lots of dust. I took it home and used the compressor to blast some air and clear up some of the dust, I left the head/valves and lifters soaking with WD40, hopefully things may loosen up. Anyone have an idea as to why the valves may be open, may something was resting on it and caused the spring to compress and then it becoming caked with crud. I am going to be doing the same thing but what I decided is to take the adapter for the individual throttles and shape the entry to that of the Neo as the Neo has a wider intake opening and leaving the RB26 intake with just enough to get by without leaking. I picked up the Neo head for $150USD, wasn't too bad. How do you'll go about removing the lifters, they are pretty snug in there at the moment? Keep the updates coming as it has indeed inspired me. Jason.

Great looks like the best option for me and that way I can keep my VCT and not have to use the RB26 head. Any insider info that may come in handy when I am doing it, top job by the way? I guess if you wanna run twin turbo the same applies, wels shut and build up and throw the two twin manis on for the twin setup. May actually do that when the head comes off same time but not weld the original setup shut as yet. Thanks again. Can wait to see the outcome.

Does it make a difference if I use RB25DE or RB25DET ARPs, are they the same? This is for an RB26 head on an RB25DET block.

Any pics of the individual throttle over the intake side? This is may be an option for me, did you use the RB26 Intake Manifold Gasket as a reference to know what needed building up and what needed blanking as well? Good work thus far and let me know when you have any progress on it as I should have an entire throttle and twin setup off and RB26 today. Seeing as the RB25DET Neo has solids and GTR rods I may stick with this option as most people have persuaded me to keep my Neo head being that it is newer and not swap the head for the RB26 non-VCT one. I am tihnking to get a Neo head thought for this project and do everything external and just swap heads when done. Keep the updates coming.

Any links to the conversion and any hints as well?

What would it cost to ship the block to me in Trinidad? Also whereabouts I can get the adapter plate for the setup, I remember Blitz had a plate. Let me know. Also has anyone used the twin stock manis and changed the flange to the head on the RB25 successfully? Thanks for a perspective and an option for the throttle setup.

Have you contributed anything positive to this entire discussion? I won't stoop to your level, how old are you damn? So what do people recommend as a forged setup for the block to bring up the CR a bit?

Nice, good to see someone up on that side, I know a couple of friends with SRs up there as well. Good to hear. What is your setup like?