zac the muss

Does anyone know the piston dome volume for an Neo r34 RB25de? Reason being wanting to put a basic RB25 block together for a turbo build, already have an S1 rb25 head and can get my hands on a Rb25de neo block fairly easily. Have worked out the dome volume of the piston should be around 12cc by plugging numbers into a C/R calc and comparing results with r33 and neo head chamber volumes. Going by this an R33 head on a 25de Neo block would have a CR of 8.3 and with .5mm taken off the block would give 8.7 which could be ideal for a turbo build ? Does anyone think this is a good idea? My reasoning is the 25det neo has a better piston with stronger ring lands so am guessing non turb will be like this also I know the better idea is to get an rb25det block and go from there but is more $$ and will likely be doing a basic rebuild anyway so dont mind trying something different Any criticism/advice appreciated!

anyone have an answer to this?

you must be doing something wrong if your rails gone raw mate.

just a quick question, is it possible to drop rb26 valve springs into an a r33 rb25de head? I've done a bit of searching but haven't been able find a definite answer. the plan is to stay with the standard DE cams for now. also is there any sort of quick check to determine the condition of the springs? cheers

so are you saying afms are in some way better than running a map sensor?

there are a few drift cars over here with single throttles, all running around 400kw.

supposedly it's easier to tune with a single throttle body rather than the ITBs. RIPS here in nz uses a single for almost all of builds.

haha thanks for the input guys. seems like a lot of speculation going on here. as for ditching hydro lifters and side feeds? I'm not building a 700hp competition motor, just want a solid setup that makes enough power to have some fun on track. clearly a neo 25det is going to be better than an r33 one but I don't have 3k to throw at a drop in motor, nor do I want one as you end up throwing away everything bar the block and head when going for decent power. il probably end up hacking the lumps out of the exhaust ports as to me it seems completely pointless to have them there, and every little but counts right? my main focus for this build is to get the oiling 100% sorted and reliable on track before going to a 30 bottom end, hence why I'm picking up a 25det neo block and crank to save having a collar put on the DE one, oil squirters are just a bonus. this is a project remember, I don't need a built 30det next week. I'm quite happy to build a cheap(ish) motor and run it before going down that track. things like this can serve as a great learning curve.

As far as I'm aware r33 25det cr is 9 and neo is 9.5. I like the idea of running a neo head however I already have this motor so may as we'll use it. the r33 head is easier to work with anyway and greddy plenums bolt straight on which is a bonus. I'm buying the neo block and crank without rods or pistons so may source some r33 turbo pistons or rebuild with the high comp DE ones.

cheers guys, looks like I'm best to leave it alone for now. my goal for this build is around 300kw. the idea is to get a decent turbo setup running on it before switching to an rb30 bottom end built with some decent gear. it's going into a track car so I want to use the cheap motor as a testbed to get things reliable before throwing some $$ at a decent bottom end. the head and sump will be coming off so it'd be stupid not to at least do a basic rebuild. I can get hold of an rb25det neo block and crank (hopefully with proper oil pump engagement) so will probably pick that up and hopefully some turbo pistons if I can get a hold of some.

So I've got myself an s1 rb25de which I'm planning to bolt a turbo onto. is it worthwhile removing these little bumps in the exhaust ports and opening them up a bit? the head will be coming off for some block restrictors and a few other things anyway but I'm yet to decide how far to go with rebuilding it. please excuse the noob question I'm new to this whole engine building thing.

Does anyone know if you can put rb26 rods and pistons into an rb25de? I'm wondering if this would be a good way to get the strength up/compression down for a turbo. Anyone done this/ able to calculate the comp ratio?

Good to see the car back at it. Have you guys considered running an Neo RB20 head with the bigger ports, solid lifters, vvt etc..?

An RB20det neo sounds like an awesome idea, and good on the guy who goes out of his way to do something different. I myself, along with alot of other people happen to like rb20s, theyre a good motor in thier own right, they sound good and rev like buggery, but just happen to be overshadowed by 25/26/30s etc.. as for rolls, cant you go and be a wanker somewhere else?

The drivers side window in my r32 has recently shat the bed, does anyone know if you can use a part from a cefiro, laurel, stages etc to fix the window actuator? Or does it have to be a direct replacement from the same model. It's an r32 coupe. cheers