My 25/30 Build

[the_jack]

g'day

i decided to build a 25/30 for my vl after seeing the results people on here have achieved quite cheaply on here

parts i have sofar:

rb25det s2 head - has bin welded and is getting machined and pressure tested atm.

ebay rb25 highmount turbo manifold

greddy copy plenum

6x bosch mec717 coil packs

sard 660cc injectors

microtech lt12s with x6 igniter and microtech loom for rb25

pro boost t66 turbo 1.00 rear 1.07 front (from memory) - may go for a 35/40

tial 42mm waste gate

ebay intercooler with 2"-3"piping

3" vband dump pipe from turbo to cat

3" mandral bent exhaust

malpasi fuel reg

r33 gts-t gearbox

brass button clutch

surge tank

new rear main seal

to buy:

head gasket

head studs

oil pump

new water pump

sump gasket

044

timing belt

oil restrictors

t3-t4 flange adaptor (or weld on t4 flange)

there are other little things i have prob forgotten but ohwell.

my plan is to use the rb30e bottom end that is in the car now, put in 1mm oil feeds and a new oil pump (which one should i use?) and bolt the head on with arp studs and a genuine nissan rb30et head gasket and hope for the best. any ideas how far i will get? im putting an rb30et in while im building the 25/30 just for fun

later on down the track i may go all out with a full forget 25/30 setup using parts from this setup

thoughts and opinions?

cheers

Edited January 25, 2011 by the_jack

[JonnoHR31]

oil feed size depends on oil pump used, use of the car and whether or not your using them to feed vct aswell. if your buying an oil pump i'd get a 25 pump, otherwise use whatever you've already got.

sump doesnt have a gasket, use some high temp gasket silicone.

timing belt will also determine what you have to do with tensioners. if using a 150T belt (such as the gates 30det belt) then use 2 tensioners in the standard locations (next to each other down the bottom), if using a 152T belt then you need to relocate one tensioner as per the 30det guide.

also i'd steer clear of the malpassi reg, standard ones are much better....

[KiwiRS4T]

Rings, bearings, rod bolts.

[the_jack]

oil feed size depends on oil pump used, use of the car and whether or not your using them to feed vct aswell. if your buying an oil pump i'd get a 25 pump, otherwise use whatever you've already got.

sump doesnt have a gasket, use some high temp gasket silicone.

timing belt will also determine what you have to do with tensioners. if using a 150T belt (such as the gates 30det belt) then use 2 tensioners in the standard locations (next to each other down the bottom), if using a 152T belt then you need to relocate one tensioner as per the 30det guide.

also i'd steer clear of the malpassi reg, standard ones are much better....

yeah im planing on runnung vct and was going to use a 25det pump. i was also planing on running the gates 30det belt

[the_jack]

Rings, bearings, rod bolts.

what ones would you recomend?

[JonnoHR31]

yeah im planing on runnung vct and was going to use a 25det pump. i was also planing on running the gates 30det belt

well if your doing the internal vct feed from the cam buckets then you need enough oil to supply that aswell. standard 25 has 2 main 1.5mm feeds and a 1.5mm feed for the vct, so 3 x 1.5mm feeds all up. i personally used 2x1.6mm feeds with a 25 pump and vct, which works out to a little less flow than standard 25 setup, havent had any issues yet.

gates 30det belt is 150T so use 2 tensioners in the standard locations down the bottom, make sure the belt doesnt get too close to itself

[the_jack]

turns out the head i purchaced had leaking valves so iv had all new seals put in it and should be getting it back next week. also iv picked up an rb30e with only 140xxx km on it so i should be putting it all together in the next couple of weeks

[the_jack]

update:

ended up scrapping the ebay exhaust manifold and picked up a 6boost manifold nice and cheap. have got just about everything to put it all together now except for a TPS, timing belt, spark leads and a few other bits and pieces.

this week im going to drill out and fit my oil restrictors then bolt the head on (finaly)

question time:

i have bin told i can just press in the new oil restrictors ontop of the factory ones?

i already have a stainless T4 flange i brought for my other manifold, is it possible to chop off the T3 flange off the 6boost mani and weld on the T4 flange?

where can i buy my timing belt from? iv looked everywhere but the part number listed in the how to thread is different to the ones listed on the gates website.

with the VVT oil galery on the rb25det head, what size should i drill it out to? Im useing 1.6mm oil restrictors in the block.

im useing an rb25det oil pump. will it fit straight on the rb30e crank or do i need a crank collar such as a spool imports once?

cheers

Edited July 18, 2011 by the_jack

[JonnoHR31]

just tap the restrictors into the block and push the old ones down, no need to drill them out or anything.

you can use either the gates 30det 150t belt or the 152t dayco. if you use the 150t and your head and block havent been machined down majorly you can use the 2 factory tensioner locations at the bottom of the block. if you use the 152t belt you must relocate the tensioner as per the guide.

i drilled the brass plug out to 1.5mm as thats what the standard 25 vct feed is.

25 pump will go straight onto the 30 crank, however you'll only have a narrow drive so dont go bashing limiter too much.

Edited July 18, 2011 by JonnoHR31

[the_jack]

ok sweet

any info on the t4 flange?

cheers

[JonnoHR31]

would depend on what the 6boost is made out of?

[the_jack]

im guessing steem pipe/mild steel?

[the_jack]

ok exhaust manifold is sorted.

now next problem: im running a standard rb30 crank with a rb25det pump - will i need to run a crank collar and what would i need to to to be able to fit it?

cheers

[JonnoHR31]

you dont NEED to, but it'll be stronger with one. to fit a crank collar you need to remove the crank and get it machined to suit the collar, then fitted and grub screwed. or you can get the crank welded then machined with a wide drive.

if your motors already assembled and your not planning on bashing limiter constantly at crazy revs i wouldnt bother.

[the_jack]

yeah since its not a built bottom end im not going to be limiter bashing too much. oil pump is already on the motor anyway

dropped my 6boost manifold off to get the t4 flange welded on thisarvo. going to finish cleaning the block and giving it a coat of paint this week then going to assemble everything next weekend and about time!!!

[the_jack]

Am I going to need adjustable cam gears with the 150t belt? If so can you still use vvt with them?

Cheers

[JonnoHR31]

no, you just need 2 tensioners. aslong as you havent had the head or block machined heaps of times or had a lot taken off you'll be able to get the cam timing spot on by adjusting the tensioners

[the_jack]

Ok sweet. Ordering a timing belt today and the motor is going together Sunday morning finally!

[the_jack]

got my manifold back from being modified on friday so i bolted up the hotside to see how much room iv got. just need to figure out where im going to mount the waste gate now as it had to get cut off to make room for the t4 flange

[JonnoHR31]

where are you gonna run the oil breather pipe to? might need to get a T piece for your turbo oil return