Rb25det Rebuild

[dangerman4]

who has been down this road and what parts did you use to achieve what goals?

advice would be apreciated.

[Bass Junky]

I hate to say it dude, but do a search.

Also, check the RB25DET turbo upgrade thread.

[Abo Bob]

And be way more specific if you want real answers.

[dangerman4]

have searched...

basically i have some ringland issues so a full rebuild is in order.

i have allready got forged pistons, and forged h beam rods,

and have sent the motor off to get bored, and crank balanced etc.

now my general question more refered to what else shoud i do while its apart.

my car is a r33 s1 4 door auto.

consists of

full 3 inch exhaust turbo back

high flow cat

600x300x80 fmic

gt3076r-sp

stainless exhaust manifold

nismo 550cc injectors

q45 afm

power fc

walbro pump

sard fuel reg

MV Automatic shift kit

Any suggestions?

cams?

[Craved]

id go some cams , and head work .. port polish..

get them to check the valve guides stem seals too.

tomei poncoms are good, or go slightly bigger HKS items. these both work with std lifters and springs.

[stuartlaw_78]

Hi mate..

I've just finished rebuilding my RB25DET engine. I've now done 7,000kms and haven't had any major problems (touch wood!)

While the engine is apart, I would change your water pump (about $40-$50), def change the thermostat (under $50)... you could do the oil pump if you wanted to, I didn't though...

You gonna change your clutch while it's all apart? I think it was called the 'thrust bearing'.... replace that... aparently the 'piolt bush' should be replaced as well...

Are you going to build the engine yourself?

If you've got any questions... just ask me.. I'd be more then happy to help.. I've been there and done that so fire away with any questions you have and I'll do my best to guide you in the right direction.

[Abo Bob]

I don't know that turbo so I don't know how far you are expecting it to take you but I would suggest you ditch that fuel pump and put something decent in there.

Tomei Poncams (type B) are good.

I wouldn't port the head but a polish of the combustion chamber would be worthwhile.

I would have expected things like water pumps and oil pumps would be replaced as a matter of course.

Put a crank collar on for the oil pump drive if going over say 250rwkw.

Have you thought about what compression ratio you are going to run?

[JCMarshall_Law]

How much did it cost you?

Did you do it yourself or workshop - which one?

Standard new parts or heavy duty after market stuff?

What power you got now?

Hi mate..

I've just finished rebuilding my RB25DET engine. I've now done 7,000kms and haven't had any major problems (touch wood!)

While the engine is apart, I would change your water pump (about $40-$50), def change the thermostat (under $50)... you could do the oil pump if you wanted to, I didn't though...

You gonna change your clutch while it's all apart? I think it was called the 'thrust bearing'.... replace that... aparently the 'piolt bush' should be replaced as well...

Are you going to build the engine yourself?

If you've got any questions... just ask me.. I'd be more then happy to help.. I've been there and done that so fire away with any questions you have and I'll do my best to guide you in the right direction.

[SirRacer]

RB26 cylinder head= 2 oil feed galleries between the block and the head

We block one off, same as RB26's are standard

We use a 1.5 mm restrictor in the other

Plenty of oil flow to the camshaft bearings, not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

RB25 with VVT= 2 oil feed galleries between the block and the head

Plus 1 feed to the VVT actuator

We block one off, same as RB26's are standard

We use a 1.5 mm restrictor in the other

Plus leave the VVT oil feed as per standard

Plenty of oil flow to the camshaft bearings and VVT actuator but not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

RB25 without VVT= 2 oil feed galleries between the block and the head

Plus 1 feed to the VVT actuator

We block one off, same as RB26's are standard

We use a 2.0 mm restrictor in the other

Plus block off the VVT oil feed

Plenty of oil flow to the camshaft bearings, no VVT actuator. Not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

[dangerman4]

the head has had a full three angle valve grind, and all stem seals replaced.

i was more thinking down the track changing to a rb26 head..

due to big cams and lifters..

will they bolt straight on?

my original question i was wondering if any one else has done the full rebuild,

how much grunt?

did you lift the standard 7000 rpm limiter to 7500 or 8000 with new rods and pistons?

any other experiences?

[campbell]

well i got 582.7hp out of my rb25 and thats without nos

depending what funds you have.

head

tomi cams 270 deg with 10.5mm lift

ferrera double valve springs

ferera 2mm oversize valves

solid buckets

cutom lifters

wesco conrods

race bearings drilled

heat treated stnd crank je rings

cp pistons

extra oil galleries

n1 oil pump

n1 waterpump

bored out 20thou

everything port and polished

flow tested..

[dangerman4]

wow!!!

434.5 kws

im asuming thats at the wheels?

good effort fella..

so is that the rb25 head or a 26 head?

and how large was your turbo to do that?

whats your redline set at?

and whats it like to drive?

cheers

[campbell]

all rb 25 head and block.....

run a t51r 22psi yea thats at the wheeles i have a 100hp nos shot for it also but its a not to bad to drive when it comes on boost you really no it....

[stuartlaw_78]

How much did it cost you?

Did you do it yourself or workshop - which one?

Standard new parts or heavy duty after market stuff?

What power you got now?

Hi mate... in answer to your question.. I built the engine myself but got the machining done by pro's..

All up I spent about $7,000 and I did put heavy duty parts in because I'm aiming to get 300 at the wheels.

After I had run the engine in.. I had it dynoed and running about 9PSI with stock intercooler, I got 176kw at wheels... not bad I thought..

I've now brought a Hybrid front mount and will soon buy an aftermarket ECU, then I will probably run 15 - 20 PSI through it and see how much power I get then...

I did post up a thread here a few months back on my entire rebuild.. I can't remember what I called it but search and you might have soome luck...

[Abo Bob]

This is probably it.

http://www.skylinesaustralia.com/forums/in...opic=103538&hl=

[dangerman4]

so whats the story with running a N1 oil pump in a rb25det?

the car wont be doing any track work just a quick streeter.

im well over ten grand on the engine so i want the right pump for the job.

[BezerkR32]

take note about replacing valve springs, even smaller cams 256 with 8.5mm lift require more seat pressure.

standard springs start to fall over when you make around 275-280kw at tyres. a decent turbo pushing 20psi will overpowrer them. seems like you have downstairs sorted, but all the power is made upstairs.

well i got 582.7hp out of my rb25 and thats without nos

depending what funds you have.

head

tomi cams 270 deg with 10.5mm lift

ferrera double valve springs

ferera 2mm oversize valves

solid buckets

cutom lifters

wesco conrods

race bearings drilled

heat treated stnd crank je rings

cp pistons

extra oil galleries

n1 oil pump

n1 waterpump

bored out 20thou

everything port and polished

flow tested..

[BezerkR32]

just on the quiet, if your looking to push that much boost through it I suggest you sell your Hybrid & buy a quality, more efficient core for it.

Hi mate... in answer to your question.. I built the engine myself but got the machining done by pro's..

All up I spent about $7,000 and I did put heavy duty parts in because I'm aiming to get 300 at the wheels.

After I had run the engine in.. I had it dynoed and running about 9PSI with stock intercooler, I got 176kw at wheels... not bad I thought..

I've now brought a Hybrid front mount and will soon buy an aftermarket ECU, then I will probably run 15 - 20 PSI through it and see how much power I get then...

I did post up a thread here a few months back on my entire rebuild.. I can't remember what I called it but search and you might have soome luck...

[Craved]

tomi cams 270 deg with 10.5mm lift

ferrera double valve springs

ferera 2mm oversize valves

solid buckets

cutom lifters

would love to get some details on how much and where you got the above parts from..

looking into this kind of setup on a rb25/30 but the tomei rplacement valve springs and solid lifters are unavailable.

cheers