How to RB30/25 Swap into an R34 [Video]

[Joni Boi]

Hey guys,

I'm back with another tutorial that I made (thanks to isolation). This is on a how to swap the RB25 bottom end to a RB30 bottom end with a 25 head in a R34 (R33s and R32 should be kinda similar i think) that I did last year. I had to split the tutorial into 3 parts (each part is like 15mins). It starts with preping the RB30 block, to taking out the RB25, and then putting in the RB30/25 and starting it.

The reason why I did an RB30 swap was not because of an upgrade but because my RB25 was showing up bad results on the comp tests and there were cheap RB30s going around (I actually made money out of selling parts from the RB30 that I didn't need lol). The goal for this car is only to be a daily responsive streeter on pump fuel (won't ever take it to the track). 

It's my first time ever doing something like this (I had no help, did this on my own), so take it as a guide line. If I were to do this again, I would definitely use a proper engine crane and take the whole engine out including the gearbox next time, but yeah... this was a real poor mans job and it got the job done and I've been driving this RB30/25DET Neo everyday to and from work as my daily and I've never had a problem with it (have been clocking 5000+ Kms on it as of 10/4/2020). 

 

Here's the videos:

Part 1:

Part 2:

Part 3:

I'm really happy with the outcome. Considering I knew nothing about RBs or any engine before I bought this R34. I learnt everything from researching (a shit load) on these forums, so thanks SAU, here's me giving back. 

The car ended up making 323.8 HP on the dyno with my OP6 highflow turbo which is a bit too small for this engine. So I will go with a bigger one in the near future.

List of mods on my car previously that I brought over to the RB30 swap:

• HyperGear G2 RB25DET OP6 highflow turbo with ballbearing
• 3" turbo back exhaust
• 100mm thick FMIC
• Splitfire coil packs
• Xspurt 525cc injectors
• HDI EBC
• Nistune ECU
• Z32 AFM
• Walbro 255lph fuel pump (hard wire mod) 98RON
• Exedy HD clutch
• External oil cooler
• Koyorad all aluminum radiator

 

Just something to add here on the side if anyone was interested (kinda like a build page, but I might as well put it here). This was my whole budget explained:

So the total amount that I spent on this build/recon/swap was $3415.

I bought a complete RB30 engine (without the box) for $150. Apparently this engine was used in a TAFE course for mechanic students to practise timing stuff on, so the pisons had heaps of screw driver marks on. A recon was in the picture anyways because I want this engine to last for ages. So I only wanted to keep the block, crank and rods. I sold everything els (head, alternator, ecu ect) for $240. That's already a profit of $90 lol! The reconditioning of the RB30 block and RB25 head was the most expensive out of the whole budget costing $1420.

The recon from Harris Engines in Perth:

• $400 - Bore and torque plate hone
• $190 - Face block
• $180 - Machine and fit crank collar
• $90 - Acid bath
• $90 - Face/deck RB25 head
• $50 - Acid bath head
• $90 - Face flywheel
• $150 - Fitment of pistons to rods
• $180 - Balance rotating assembly

All other things:

• $270 - 1mm oversized Hypatec RB30ET set of pistons + Hastings Rings
• $253.45 - RB25 ARP Head stud kit (202-4301) from wolf racing
• $261.25 - RB25DET Neo genuine nissan gasket kit
• $106.49 - RB30 ACL race main STD bearing set 
• $88 - RB30 ACL race conrod STD bearing set
• $30 - RB30 small end rod bushes/bearing set
• $99 - RB crank collar from Lewis Engines
• $38.75 - RB oil restrictors (one 1.5mm and one blank one)
• $38 - RB30 brass welsh plugs
• $13.71 - RB spigot bush
• $38.98 - RB genuine nissan timing belt fastner kit
• $41.5 - genuine nissan thermostat
• $78.14 - Genuine nissan R34 pull type thrust bearing
• $110.5 - Genuine nissan RB25 exhaust manifold fastner kit
• $43.2 - Dayco 94407 (T866) timing belt
• $72.11 - Mamba RB30/25 turbo water braided line kit
• $81.59 - Braided -4AN hose + fittings for the external VTC feed from Enzed
• $330 - Dyno tuned car by C-Red in Perth

All of the labour except for the recon and tuning was done by me. 

[CowsWithGuns]

Hey mate just watched all your vids. I spent hours looking for a decent writeup and this beat all my expectations. I'm slowly making preparations to do exactly the same thing, thanks for the inspiration and help!

[KEBAB_DRIFTER]

Quality post , thanks for taking the time to video the process

[NiHaoMiaoMiao]

Wow, just thinking about the rb25 neo with the 30 block and come across your thread! great read and watch!

might need to go ffp due to bonnet foul?

[Joni Boi]

On 16/08/2020 at 3:56 PM, NiHaoMiaoMiao said:

Wow, just thinking about the rb25 neo with the 30 block and come across your thread! great read and watch!

might need to go ffp due to bonnet foul?

Thanks! I've heard some guys on here have gotten away with the stock R34 GTT bonnet. Mine is aftermarket (Z-tune fiberglass i think?) that has fins pointing towards the engine and they did foul on the stock intake plenum and throttle body aswell as the intercooler pipe running over the fan and it couldn't close. Because it was fiberglass, I just grabbed a dremal and hacked away on the under side of the bonnet to make it close. It barely closes now and is still rubbing on my intake plenum and pipe. These Z-tune bonnets come with a tray under the fins so that you don't get rain dripping on your engine. I can't run that tray so I just use aluminium tape to close the fins. I wish I could go FFP, only for the clearance and ease of service but they are out of my budget.

 

The engine is now on the 10000kms mark. Been using the car everyday to and from work. Hasn't had any issues yet. Running mint as ?. There is still a little oil leak coming from that f*c@ing!!! external shitty VCT weld which is causing my belts to be a bit oily which is not good for the timing belt. But it doesn't drain my oil under the dip stick mark before the next service. I will have to replace it and see what I can do with the leak some time. 

It really feels like it needs a bigger turbo. I can't wait to get a new one. I was thinking of hypergear's ATR45 BB? Just a simple bolt on to stock rb25 mani. 

[NiHaoMiaoMiao]

On 9/10/2020 at 7:59 PM, Joni Boi said:

Thanks! I've heard some guys on here have gotten away with the stock R34 GTT bonnet. Mine is aftermarket (Z-tune fiberglass i think?) that has fins pointing towards the engine and they did foul on the stock intake plenum and throttle body aswell as the intercooler pipe running over the fan and it couldn't close. Because it was fiberglass, I just grabbed a dremal and hacked away on the under side of the bonnet to make it close. It barely closes now and is still rubbing on my intake plenum and pipe. These Z-tune bonnets come with a tray under the fins so that you don't get rain dripping on your engine. I can't run that tray so I just use aluminium tape to close the fins. I wish I could go FFP, only for the clearance and ease of service but they are out of my budget.

 

The engine is now on the 10000kms mark. Been using the car everyday to and from work. Hasn't had any issues yet. Running mint as ?. There is still a little oil leak coming from that f*c@ing!!! external shitty VCT weld which is causing my belts to be a bit oily which is not good for the timing belt. But it doesn't drain my oil under the dip stick mark before the next service. I will have to replace it and see what I can do with the leak some time. 

It really feels like it needs a bigger turbo. I can't wait to get a new one. I was thinking of hypergear's ATR45 BB? Just a simple bolt on to stock rb25 mani. 

Yes, that's great to hear she's running mint! 

Fingers crossed mine fits as I have a stock bonnet ?.

I am also in the same boat in regards to the FFP, a lot of money for really not much gain performance wise (esp losing low down torque!)

It is a shame about your external feed though, I resorted to using a kit I found from a NZ performance shop, which I'll link for you here.
https://franklinperformance.nz/products/nissan-rb30det-vct-oil-feed-kit
It cost me like $105 delivered and only took 3 -4 business days so worth a look. (it also comes with instructions)

I'll post up how the bonnet clearance and VCT feed goes once I get the car up and running (hopefully in the next couple of weeks...)

Also, thanks for the suggestion there with the turbo, they look very good value for money, as I also want to retain as much of a factory look as possible!

[Rusty Nuts]

On 9/12/2020 at 8:42 PM, NiHaoMiaoMiao said:

There is still a little oil leak coming from that f*c@ing!!! external shitty VCT weld

There is NO necessity to weld anything to feed oil to the neo VCT. This is how I did it back in 2017. Still works perfectly.

 

[Rusty Nuts]

[Rusty Nuts]

On 9/12/2020 at 8:42 PM, NiHaoMiaoMiao said:

It cost me like $105 delivered and only took 3 -4 business days

Mine cost $8.00 and I got it from supercheap the day I needed it. Don't forget the KISS principle.

[NiHaoMiaoMiao]

18 hours ago, Rusty Nuts said:

Mine cost $8.00 and I got it from supercheap the day I needed it. Don't forget the KISS principle.

Yes, I did see your one Rusty and was my initial plan, however, when I was getting quotes done for the fittings and braided line from Enzed/Pirtek, they wanted something along the lines of $160...
Love your setup though, so nice and clean!
Mine will fit behind the backing plate of the cam cover, I'll dig out the photo...

[NiHaoMiaoMiao]

[Rusty Nuts]

1 hour ago, NiHaoMiaoMiao said:

Mine will fit behind the backing plate of the cam cover,

And obviously so does mine.

[Joni Boi]

[Update] I've finally got around putting a bigger turbo on and I also swapped the leaking vct head with a different head that i didn't weld this time! 🤣 Just drilled and tapped the head for the external vct feed. Theres plenty of meat. I don't know why I got the other one welded. I think when i did all my research on this, i did see someone say that you have to add more meat on for the threads. Oh well. New head is running good! No leaks at all. I actually bought this other Neo head 2 years ago from gumtree complete with valve train already machined because my intake cam gear's rear bolts loosened over time and one of them rattled loosely inside my timing belt then eventually broke the intake gear. Luckly i was just leaving for work driving slowly up our street and the car just shat its self and turned off. I had to push it back home and found out what happened. So i instantly thought the valves must have kissed the pistons and thus why i bought another head. After i replaced the intake cam with another one, i tested the compression and it was still fine. Also ran fine and ive been driving like this for ages.

I recently took that old head off and saw no damage to the valves or pistons. So then i just cleaned all the old gasket off, gave the surface a bit of a hone with oil stone and put new nissan head gasket on, placed the other head on, and everything els.

I went with a Hypergear ATR45 .82 rear ball bearing turbo with a Turbosmart 45mm external wastegate that Hypergear welded onto the rear turbo housing and then plumbs back into the dump pipe. I also upgraded the coils to PRP R35 coil kit. I then went to get it tuned and made 367hp. Tuner said straight away, the Z32 maf and nistune is now the restriction and i will be going Haltech soon. 

The engine has now done 41000kms and its going f#ck!n mint. No leaks at all now. My little brother also has a R34 GTT. We also did the exact same RB30 bottom end swap like i did. He also has the exact same mods that i have except he has Haltech platinum pro and his made 415hp and hes loving it.