how can i tell the difference between both heads my mates friend is selling a RB25 head it has no manifolds or turbos nofing my other mate wats to put it on hsi commo and my mate is telling me its a Turbo head but wen i seen it the 1st time it had a non turbo manifold on it but he is still telling me its turbo?? how can i tell if its turbo or not?? is there a way i can tell????

I;m guessing cams may be the only difference. Different valve sizes between the RB20 and RB25 which helps distinguish the two. Other than that - check lift?

Nah i mean by looking at the engine? like i cant pull it apart and check u know wat i mean ? like any pipes or somthin that is on the turbo 1 and not on it non turbo head or somthin????

Are you sure the turbo head doesn't have 2500 intercooled turbo written on it somewhere, I could of sworn i'd seen it, unless that was a soarer head I'm thinking of. Ask some jap motorsport business if it really concerns you as you want to make sure you get what your asking for!.

u are right it is suposed to have a sticker on it but the sticker has been taken off. cause i can see the sticky mark.

umm just maybe, there is a difference between the oil and water galleries at the front of the head. I am not full bottle on this but an RB25de head should be able to bolt straight onto the RB30 bottom end as the galleries match well. If you have seen/downloaded a DIY rb30de from the skyline forums, there are pitcures in the file describing the heads but in minimal detail. Just thinking if the head matches the rb30 galleries closely, it could be an rb25de and if not, it could be an rb25det because they use VVT. However *sigh*, it also depends on the model r33/32, hmm.... sorry, i cant help u lol

I've recently reworked my guide as my RB30DET has just been completed TODAY!!!!!! But yer.. Not much difference between the R33 RB25DE & R33 RB25DET heads. Bit of a pain in the arse the R33 head is actually (vct). I would use a R32 RB25DE head slap a set of 264 cams in it from greenling ~800 and off u go. The R32 & R33 heads are basically the same. Stock exhaust cam is slightly smaller in duration/lift for the R32 RB25DE head. A list of cams specs are in the guide. Its all in the guide.. Be sure to let me know if anything is a miss. EDIT: Oh the origonal question. If its a turbo head then it HAS to be a R33 VCT head. The inlet cam gear will have a bulge on it. If its a NA head from the R33 then it will also have the bulge on it. To be honest if its a R33 turbo or non turbo head it doesn't matter. They are both the same. If its the R32 RB25DE head then it is slightly different just without the VCT. I wouldn't be concerned about it being a turbo or non turbo, I'd be more concerned that you don't get ripped and pay the price for a R33 head when really it is a R32 RB25DE head. Neither R32 or R33 head is better than the other. VCT is thrown out the window once you fit aftermarket cams so I see it as wasted money. I paid $750 from Adelaide Jap for my R32 RB25DE head. They thought it was a R33 head but it wasn't. It came with injectors, inlet manifold, plenum etc. Everything I needed. I then spent $880 on a rebuild mild port polish inlet valves deshrouded. + 275 on the vrs kit + another $80 to fix a valve seat because I noticed a protruding exhaust valve seat (detonation causing) that Criss Miltons Engineering missed when first doing the head. I had the bottom end done at City Dismantlers by the Wizz Andrew. Some original photos have not been recovered yet.

so the heads are basically the same its just i heard that the springs are softer then the turbo model. i wanted to boost my turbo up a lil and i am unsure wat injectors i would have if i didnt know what head i had u know what i mean wat boost would i be able 2 run on a RB25DE head then if its non turbo?

Heads are the same and the valve springs are suited to the cams. There is absolutely no point changing the valve springs unless you change the cams. I wouldn't be boosting unless the injectors had been cleaned and flow tested anyway. Then at least you know for $15 per injector that you arn't going to lean out a cyl. and blow the new motor.

head castings are the same, like has been said only cams and springs are different. The way i understand it the DE non VCT cams are the best to use due to higher lift. As far as i was aware the R32 was only DE and no VCT, R33 was both DE and DET and VCT was avaliable on both engines. The Non VCT heads are easier to fit up, they bolt straight on, the VCT heads need the oil gallery for the VCT plugged and redrilled in a different place to get the VCT to operate.

ok.. Here's the specs. R32 RB25DE Inlet - 240dur 7.8mm Lift Exhaust - 232dur 7.3mm Lift R32 RB20DE Inlet - 232dur 7.3mm Lift Exhaust - 240dur 7.8mm Lift R32 RB20DET Inlet - 240dur 7.8mm Lift Exhaust - 240dur 7.8mm Lift R33 RB25DE & DET both have the exact duration/lift cams. Inlet - 240dur 7.8mm Lift Exhaust - 240dur 7.8mm Lift R34 RB25DE Inlet - 236dur 8.4mm Lift Exhaust - 232dur 6.9mm Lift R34 RB25DET Inlet - 236dur 8.4mm Lift Exhaust - 232dur 8.7mm Lift The lobe centers also vary between the turbo/non-turbo & models. Nothing a set of adj. cam gears can't sort.

Cam specs for all R32/33/34 GTS/GTST/GTR http://www.tomei-p.co.jp/_2003web-ca...aft-specs.html (http://www.tomei-p.co.jp/_2003web-catalogue/e090_camshaft-specs.html)

very nice work Joel letus know wot power u do

500-550hp.. No ifs no buts.. The cars a streeter. So i'm after huge mid range torque. Some original photos have not been recovered yet.

so 380-420rwhp? wot turbo u runnin again?

HKS3037 .87 exhaust a/r. Should do the job nicely. I know they make around 320rwkw on a RB25 with around 20psi of boost. In Japan they have made 700rwkw on a RB26DETT in twin form.

very nice im hopin to b able to import them aswell as all the other HKS range, so if u wanna run twins, let me know Some original photos have not been recovered yet.

hehe If I ran twins my rods would look like Bannanas. Some original photos have not been recovered yet.

if u dont tune it 2 aggressive n hav them shotpeened ect then they should hold close to 600rwhp

hey i just noticed that i have the pipe coming out of the RB25 head near the front on the exhaust side and its been crimped shut???i got a pic how do i put it up???