AngryRB

Why not fill with E85 and see how it reacts.. do a few pulls, it might pull hard

I would have the injectors checked for flow just to rule that out. And might not be but the vct gear could be playing up, that can do odd things, might be too advanced (the slots at the back).

2 Questions Will an r33gtst vct gear fit/work on an R34 Gtt head? Will r34gtt cams bolt down and work on an r33 head? ( assuming an r34 cas is used)

Slowly progressing, the bore isnt worn much so gave it a hone and because im cheap im putting the RB25 pistons and rings on the RB30 rods rather than buy new rings. I measured all the differences and theres not much compression wise, i think will be around 8.6 roughly. Broke 2 cam bolts so had to extract them, got the crack in the turbine housing repaired too.

Even though an RB30 piston will do the job fine, the RB25 piston sitting down in the bore doesnt lose much, infact i reckon it will gain , could be 5cc extra in the dome at a guess. If a neo head and stock RB30 gives in the nines (9.3-9.5) then that 14cc smaller head bumps it up 1 point, so 5cc is say 0.3-0.4, so it could end up being 8.8ish.. The RB25 piston looks nicer , it has a thin top comp ring 1.1ish compared to 1.5 on the RB30 but they both make good power. Doesnt matter really but it saves buying new rings as the RB25 pistons and rings have very little wear so seems a good choice for this cheap slapper build.

I was measuring the difference between the RB30 and RB25 pistons. The cut outs in the 30piston are worth 5cc and the 25piston sitting 1.1mm low in the bore is also about 5cc. The 25 piston has alot of meat on the dome part so i dont know why it would be lower comp than the RB30 piston.. i measured both using syringe.. I wont decking the block anymore because the water gallery is too thin on the top. I already have good RB25 pistons with good ring end gap so its cheap to do,

Because they drop comp down to about 8.2:1, i have access to E85 also

I'm aiming for around 250rwkw so its not going to be pushed that hard, possibly 300kw later if i build the auto.. ( car is a stagea)

I wanna use the RB25 pistons, in a few threads ive read its been suggested as a good option, i just need to know how much to shave off to get 9.0:1 or better... I thought they were testing cylinder wall thickness not deck thickness..

Need some clarification, I have an RB25 piston sitting in the RB30 block and the flat of the piston is 1.1mm below deck. In the RB25 block the RB25 piston is sitting 0.3mm above deck.. So how much shall i deck the RB30 block, looks like 1.3mm will immitate a stock RB25 comp..

Was an overwhelming response to this...lol but for anyone wondering in the future the RB26 apparently shares the same piston rings as an RB30E so there you go..

Bought some hastings pistons rings for std RB30E cast pistons and the end gap is 0.60mm at top and 0.50mm at bottom. Top compression ring) The bore measures 86.10mm so i thought the gap would of been less. Can i use RB25 or RB26 oem rings? and expect the end gaps to be much closer to say 0.35mm?

Yeah its got no front drive shafts but it has the front diff so was a 4wd at some point. At this point is cheaper to leave RWD. I kinda like an auto hey, i have the R33 thats manual making 350kw so for now 250kw thru the auto would be great just to be different and maybe later build the auto with a GT 30/35 and built box but thats distant future..

So recently i got to work, pulled motor which is a bitch as always lying on concrete floor and prop shaft bolt tight as hell. Stripped manifolds off and have measured the RB30 pistons and ring end gap. Pistons still mint, 1 1/2thou clearance, ring gap on comp ring is at 0.040 which is worn so new rings needed. Bore is still round and hone marks there, its got some scuff marks but not deep so will give a light hone and push on. Will measure bearings soon. Painted block silver so i can see any oil leaks in future. Next week will order more parts and hopefully assemble the motor..☺ No excuse for not having an RB30 people, cubes for the win lol..???☺☺

So.. its not registered yet and i already bought an RB30 few months back so no reason not to treat this beast to more cubes. Its current state was -stock RB25det, fmic, splitfires,stock turbo but it has aftermarket adjustable suspension arms and tein coilovers Goals are - RB3025 with r33 head, stock mani, HKS GT-RS turbo, E85 with nistune, want low -mid range torque as its just for cruising/towing...

So was at the auctions and made maybe a bad decision, picked up an impounded stagea that was/is in poor condition. It had obviously done a big burn out as the back tires were shredded and sitting on the rims and the back doors and panels covered in black rubber. When auction was on it was me and another guy and i held on , lets just say it was real cheap. Tow truck came and getting it off the tray was a mission as its sitting on the rims on low tein coilovers. The exhaust got mangled up by the forklift at the auction as it was bent and squashed... So once off the tow truck shes got a flat battery, new battery on and she cranks and fires first time, sounded strong and the gears go in tight. So no thumps (its auto), so changed the shredded wheels and borrowed my r33s wheels and she drives. Got exhaust redone with 3inch dump, 3 1/2ihnch cat and 3 1/2inch back to fujitsubo muffler with a restrictor, sounds great. Shes got loud screeching noises when turning the steering wheel and timing belt noise. So at this point the motor is full of oil leaks and dodgy missing bolts, stupid long intercooler piping, gay dash lights etc so needs alot of work. So... i dived in and its RB3025 time lol..

Shes an rs4 series 1, yeah certainly chewing fuel, its a bit of a mystery as it looks setup for drifting, i spent long time removing rubber from the back doors so shes got enough power for a skid ?

Hey guys So.. i was at the auctions and bought an impounded auto stagea that had burned through a monster burnout and sitting on the rims, and now plan to build a decent streeter out of it, - probably a bad decision but lets play the mod game as the engine started and sounds strong ? So.. at the moment it has fmic, splitfires, 3inch exhaust, stock turbo, ecu etc... So.. what i have is an RB30 bottom end in good nick, a hks gtrs and a gt30 rear housing.. so with E85 and not wanting to rebuild auto boxs what would be a good street combo? Im not looking to rev too high as im mostly wanting strong torque from 2-4k like a Vl turbo for pulling trailers and cruising.

Still for sale??

Man thats shit, how can they not see that, im no expert but even those hone marks look rough.. Im interested what piston to bore clearance they did as hypatec pistons dont expand much..

I had issues with hot start after filling at the servo, was cranking settings on power fc..

I pulled plugs out and did comp test to see, maybe number 6 has been affected. The 155 annoys my OCD tendency, i will test that 10 more times lol ?

Tuner says injectors are dirty as he replaced Cas, coils , coil loom, fuel reg, fuel filter and then road tuned it and did a week of cold starts. It starts up quick when cold and hot, but when cold cyl 4 and 5 are dead until i get load into it in say 3rd which is a rough cold start, then is like it clears its throat and back on all 6 cylinders. Seems that the injectors are only dirty temporarily so not sure getting them cleaned will help for long but worth a try.

I've been running E85 tuned on the power fc and had cold start problems for a long time which are apparently caused by dirty injectors. So is it possible to fill with 98 and run a tank just cruising on light throttle with some reduction made on the hand controller or do i need a laptop and software and a 98 tune to switch to? I read on here that a tank of 98 every few tanks will keep the fuel system clean.

Those gate pipes look like they are at 90degrees to the exhaust flow... needs to bias the gates more so they can work properly.. Looking awesome though man.