To Rb30 Or Not?

[bubba]

+1 for RB30

[Guilt-Toy]

I do regret building my RB30DET. I should have stuck with a stocker with 300rwkw and just lived with the less power. or gone for a RB26

The reason why i say this is because the RB30DET is a major pain in the ass, sure they make good power.. i will quote the last guy i took for a drive who is into v8's "ass raping power".

But in the long run I would not suggest to anyone to build a RB30DET engine unless.

Your current RB25DET has blown up, leg out of bed and needs to be replaced and your head survived.

You got shitloads of money and you want to build a monster

You really need the extra torque and dont mind losing revs

You dont mind having a less reliable engine.

You dont mind going through oil controll issues, which are a major pain on the RB30DET

If the above seems okay to you then go for it.

remember the following when doing your RB30DET.

Follow sydney kids oil controll guide to a T. do not miss out on anything especially for a drift car thats going to be reving alot, your going to get soo much oil in the head you will be squirting oil out of the breathers and i cant tell you how much of a pain in the ass fighting that problem is.

Get the crank collar and MAKE SURE the engine builder who fits it trims the front to match the crank!!!! THIS piece of advice cost me a $1300 engine in out job for a replacement crank and NO ONE wanted to take responsibility for their f**k ups. It wore the back plate behind the timing gear and eventually lost 40 thou on the crank bolt and it came lose and flogged out the keyways on the crank, had to buy a new collar and crank and bearings etc etc.

Standard RB30e pistons will be fine, make sure you use ACL race series bearings or king bearings or nismo

Use ARP rod bolts on the standard rods, dont bother treating the rods for anything under 300rwkw

Install a GOOD oil catch can system... and i hope you got a rb25det gearbox and a good clutch.

expect to break things because these engines are tuff.

Ive had my rb30det since 2003 2004 ??? and ive been through everything during the whole learning process, it might not be such a big pain in the ass for you as it was for me but when i think about it now, i would never do it again. I would get a RB26 and push that.

Hope this helps, if you do convert then welcome to the club, this engines put a smile on anyone's face that i take for a drive, some people scream at me.

[Sydneykid]

Having built many RB30's, having one in the R32GTST and just finished the rebuild of the RB25 in the R33GTST, I have some comments;

I should have stuck with a stocker with 300rwkw and just lived with the less power.

I thought about that, but I have no faith in standard RB25's living at 300 rwkw, plus the response within the standard rpm limit for what we do is simply not there.

or gone for a RB26

Thought about that too, but I already had an R33GTST Power FC, so I would have had to change that and some wiring to accommodate an RB26DETT. No use having a RB26 if it doesn't have twin turbos IMHO, plus changing over to a single also costs more.

The reason why i say this is because the RB30DET is a major pain in the ass

I didn't find the RB25 rebuild any less of a pain in the arse than the RB30's that I have done. The all up cost was about the same, forged rods and pistons, bearing, rings gaskets, N1 oil pump, crank flange etc. Such that I could have built an RB30 for the same money, maybe slightly less.

But in the long run I would not suggest to anyone to build a RB30DET engine unless. Your current RB25DET has blown up, leg out of bed and needs to be replaced and your head survived.

Overheating in the sand trap at Wakefield, killed #1 piston. Everything else was fine.

You got shitloads of money and you want to build a monster

Not necessarily, a 300 rwkw RB30 would be cheaper to build and maintain than a 300 rwkw RB25.

You really need the extra torque and dont mind losing revs

I haven't found that a built RB30 lost any revs at all compared to a standard RB25, around 7,250 rpm is plenty for both of them.

You dont mind having a less reliable engine.

I don't see how an RB30 built to the same standard would be any less reliable than an RB25.

You dont mind going through oil controll issues, which are a major pain on the RB30DET

I had to do all the same oil control mods on the RB25 as I do on the RB30's. Since the fully forged RB25 is going to rev harder I actually had to do slightly more.

I would get a RB26 and push that.

The problem is the RB26 base engine costs a whole lot more to buy than an RB30 and they still need to be rebuilt.

Hope this helps, if you do convert then welcome to the club, this engines put a smile on anyone's face that i take for a drive

Mine is just an alternative view, not better or worse, just another look from a different angle.

Cheers

Gary

[The Mafia]

I have a NA RB30 in the garage at the moment, I just pulled the head off and it looks nearly new inside. Its done 165,000kms. There are hone marks in the bore, everything is clean as, etc.

Just curious - I have everything I need for a cheap rebuild

RB25 DET Head

RB30 NA block

Side mount manifold (Greddy copy)

GT3037 (making 314rwkw at 18psi), and have a spare 0.82 rear

RB26 Oil pump (bought new from nissan about 2 years ago, done 20,000kms on a RB25)

If I stripped the block, acid bath, new big and main bearings, RB26 oil pump, oil control mods, VCT lines, etc, and re-used the Standard NA pistons, would I be able to make about 320rwkw reliably?

Or would I be better off grabbing a set of ARIAS forged pistons or something like that and setting the compression to 9:1 and using the standard rods?

I still want to rev the engine to 7,000rpm. I'd love to build a 9,000rpm monster but that will just cost to much money, and the turbo runs out of puff anyway to make the power above that.

Not after massive power, just good torque, and about 320rwkw in the top end, and a reliable engine.

This will be going in the R33 GTS-T S2.

the reason I don't want to go all out is I want to upgrade the entire car at some stage this year (towards the end) and don't want to pump a load of money into it for the next buyer to enjoy. But as long as it is reliable, then they are still getting as new car.

Oh, and I am due for a 100,000km service and rebuilding the engine seems to be better than spending $1500 on the service alone.

Edited February 20, 2008 by The Mafia

[joeyjoejoejuniorshabadoo]

so you're looking at losing a few hundred revs but gaining heaps of mid...

i'd say go

[Guilt-Toy]

Hey Mafia

With rod bolts 320rwkw will be fine, just keep the tune fat and you wont have any issues.

I wouldnt do it if i were you, there are many hidden costs that bite you in the ass. IF your going to upgrade then upgrade dont bother with the RB30

[Guilt-Toy]

Mine is just an alternative view, not better or worse, just another look from a different angle.

Cheers

Gary

I can agree with those comments, although there are plenty of rb25's with 300rwkw and he only wants 280rwkw.

Everyone has different needs, this guy is going to keep the stock rb30 bottom end, and there is nothing wrong with his RB25 so I suggest to keep the RB25 and spend the money on something else.

just my opinion on the matter, if i could go back from day one, i would have had no modifications untill i saved enough money up for a r33 rb26 and whacked it in and gone for gold, but my case is different because the build just got out of hand and its making alot more power then i ever expected to make, I only wanted 300rwkw but a drunk night at the club saw me put a deposit on a mates gt3540 which was a poor turbo choice for what i wanted and everything else had to be upgraded to accomodate for it

Edited February 20, 2008 by Guilt-Toy

[Dale FZ1]

there are many hidden costs that bite you in the ass.

Assuming a logical approach to building / rebuilding a 30DET, what hidden costs are there? I did note the previous experience you had with the oil pump and drive flange, but otherwise?

Everyone has different needs, this guy is going to keep the stock rb30 bottom end, and there is nothing wrong with his RB25 so I suggest to keep the RB25 and spend the money on something else.

I understand the sentiment. Sounds like there has been a costly learning process in your case, but what of SimonR-32 who wants to transplant a freshened 30 bottom end under his existing head/turbo/manifolding? The information you've dropped into the thread would be invaluable in terms of getting it "right" from a reliability viewpoint for either a 25 or a 30 build/rebuild.

I thought about that, but I have no faith in standard RB25's living at 300 rwkw, plus the response within the standard rpm limit for what we do is simply not there.

I didn't find the RB25 rebuild any less of a pain in the arse than the RB30's that I have done. The all up cost was about the same, forged rods and pistons, bearing, rings gaskets, N1 oil pump, crank flange etc. Such that I could have built an RB30 for the same money, maybe slightly less.

a 300 rwkw RB30 would be cheaper to build and maintain than a 300 rwkw RB25.

I haven't found that a built RB30 lost any revs at all compared to a standard RB25, around 7,250 rpm is plenty for both of them.

I don't see how an RB30 built to the same standard would be any less reliable than an RB25.

I'd say Simon's target is to keep within existing rev range and pick up response. I don't think there is any question he would achieve that. Reliability will obviously be down to the degree of care/preparation to achieve tolerances, and the type/quality of parts necessary for his application.

My questions, based on your experience Gary would be

Rods. 7200rpm, 280rwkW. Retain stock items?

Pistons. Inspect for cracks/defects/bore clearance and reuse stock cast pistons? Or just accept new slugs as a necessity and get something of reasonable quality?

Oil pump. Assuming the restrictors and return mods are done, why not reuse a stock item?

Hopefully Simon could get the results for the application (and do so reliably) without costing a fortune

I appreciate the knowledge and hands-on experiences you blokes have, so it's a learning exercise just to listen to you both.

[Guilt-Toy]

Well some things that need attention may be.

Fuel system, will there be enough for the bigger engine ?

Turbocharger?? may run out of puff earlier and drop power in higher revs

Breathing - you need to have much bigger breathers for the bigger engine and oil catch can system (new fittings in cam covers)

Engine height, you will need to re-make engine mounts or find other means of lowering the engine or modding the bonnet and more room is required in the R32 then R33. If you change to a foward facing plenum then thats a big expense as well as the cooler piping will need to be remade.

Power steering bracket may need attention

Exaust dump pipe will need to be modified because the different length and if your unlucky the cooler piping will need to be modded.

Water lines for the turbo / oil lines, can you bend them into place without breaking them? I just replaced mine with speed flow fittings and lines, they aint cheap.

just a few things that may come up. I just dont think its worth doing unless you have wrecked your RB25 and you were going to rebuild anyway.

I do realise he is a mechanic and can do all this stuff himself, go for it. I am just trying to point out its not as easy as it looks.

Maybe he should try running a external device to trigger the VCT if he wants some of his mid range back, it will be much cheaper that way.

One thing i noticed when going the RB30DET is that it seemed to shit out engine mounts often.

Edited February 20, 2008 by Guilt-Toy

[Roy]

Its probably not a big deal in the grand scheme of costs, but all too many of these RB30 rebulds do not seem to allow for changes to engine mounts etc to clear strut braces. Power steering and other belts (dependign on model of car its being transplanted into. The cost of new intercooler pipes and dump pipes. Cost of re-charging/gassing air-con. Change to water and oil lines around manifolds. Cost of dyno time to re-tune the engine. And the big one, bother to change the engine number with the local registration...who' ears prick up when they read RB30

All for doing it, just do the numbers. Im a negative bastard when i look at these things, the real cost of these conversions is always higher then what ppl start out thinking

[Sydneykid]

Assuming a logical approach to building / rebuilding a 30DET, what hidden costs are there? I did note the previous experience you had with the oil pump and drive flange, but otherwise?

I understand the sentiment. Sounds like there has been a costly learning process in your case, but what of SimonR-32 who wants to transplant a freshened 30 bottom end under his existing head/turbo/manifolding? The information you've dropped into the thread would be invaluable in terms of getting it "right" from a reliability viewpoint for either a 25 or a 30 build/rebuild.

I'd say Simon's target is to keep within existing rev range and pick up response. I don't think there is any question he would achieve that. Reliability will obviously be down to the degree of care/preparation to achieve tolerances, and the type/quality of parts necessary for his application.

My questions, based on your experience Gary would be

Rods. 7200rpm, 280rwkW. Retain stock items?

Pistons. Inspect for cracks/defects/bore clearance and reuse stock cast pistons? Or just accept new slugs as a necessity and get something of reasonable quality?

Oil pump. Assuming the restrictors and return mods are done, why not reuse a stock item?

Hopefully Simon could get the results for the application (and do so reliably) without costing a fortune

I appreciate the knowledge and hands-on experiences you blokes have, so it's a learning exercise just to listen to you both.

My original RB30 in an R32GTR is still going strong, built in 1999. It has stock RB30E everything with an RB25DE head, just new VL Commodore rings, bearings, gaskets and seals . It made 475 bhp on the engine dyno, just a bit under 300 rwkw, using an old T04E turbo that I had lying around at the time. The rules, no more than 7,000 rpm, no more than 1 bar of boost, no leaner than 11.5 to 1 A/F ratios, zero (yes zero) knock, plus change the oil and filter at 5000 k's religously and don't try for "just a bit more power", be happy with what it has.

The RB30 crank has the narrow oil pump drive flange, it wears the oil pump flats and then the clearance hammers them till the rotor cracks. I would always recommend using a wide flange drive oil pump.

Cheers

Gary

[1400r]

25de head in a gtr ?

[bubba]

the real cost of these conversions is always higher then what ppl start out thinking

Aint that the truth So far I've spent double what I was planning.. still a couple more k to be spent to get the 35R on and tuned O_o

I love my 30 and wouldn't hesitate to do it again however I would probably do some things differently (machine the crank to begin with for example).

I'm not sure how big a difference going from 25 > 30 would make but for me, going from 20 > 30 is such a world of difference, I love it

[Sydneykid]

Its probably not a big deal in the grand scheme of costs, but all too many of these RB30 rebulds do not seem to allow for changes to engine mounts etc to clear strut braces.

The cheap China inlet manifolds and standard GTR injectors do the trick. Costs way less than buying aftermarket side feed injectors

Power steering and other belts (dependign on model of car its being transplanted into.

I have no idea why people have trouble in that area, I use all the standard stuff (off the RB25) inlcuding the harmonic balancer. That's where people get sucked in, they get aftermarket or GTR balancers and don't check the belt orientation until they have the engine ready to go, Then its a big hassle/rush to fix.

The cost of new intercooler pipes and dump pipes.

Never had to change an intercooler pipes, they always flex enough at the joints.

Dump pipe is a simple add 38 mm to the vertical, cost $50 at any exhaust shop.

Cost of re-charging/gassing air-con.

Never had to do that, I take the air compressor off the engine but leave it plumbed in.

Change to water and oil lines around manifolds.

The standard ones fit just fine

Cost of dyno time to re-tune the engine.

An always and ever present cost of increased power output.

And the big one, bother to change the engine number with the local registration...who' ears prick up when they read RB30

Never bothered, simply use the RB25 numbers.

All for doing it, just do the numbers. Im a negative bastard when i look at these things, the real cost of these conversions is always higher then what ppl start out thinking

Ever so true, the unforseen stuff always bights you.

Cheers

Gary

[Sydneykid]

25de head in a gtr ?

Yep, RB26's cost a fortune in 1999, I couldn't afford to buy one. The whole RB25DE engine was $300, nobody wanted it because it didn't have VVT, which was perfect for me.

Cheers

Gary

[Simon-S14]

wow... a lot of info in one day, i appreciate everyones imput and i know im not the only one currently weighing this up.

I cans ee where guilt toy is coming from, theres a lot of hidden extra's there but i believe i can tackle them all myself at little to no extra cost... engine mounts i can do myself, water lines, i have custom ones anyway, etc etc

I was going to freshen up a block with ACL race bearings and rings. maybe i should stick with Nissan rings and bearings, and just ensure its all done spot on?

As for revs... my current redline is 7500 rpm which some people say is too much for a series 1 rb25. however i try not to bash the limiter at all. i dont mind losing 500 rpm if it means gaining a massive amount down low.. as i said, i can simply shift up a gear and ride the torque wave.

will 7000 be a safe limit?

Cheers

Simon

[Roy]

The cheap China inlet manifolds and standard GTR injectors do the trick. Costs way less than buying aftermarket side feed injectors

I have no idea why people have trouble in that area, I use all the standard stuff (off the RB25) inlcuding the harmonic balancer. That's where people get sucked in, they get aftermarket or GTR balancers and don't check the belt orientation until they have the engine ready to go, Then its a big hassle/rush to fix.

Never had to change an intercooler pipes, they always flex enough at the joints.

Dump pipe is a simple add 38 mm to the vertical, cost $50 at any exhaust shop.

Never had to do that, I take the air compressor off the engine but leave it plumbed in.

The standard ones fit just fine

An always and ever present cost of increased power output.

Never bothered, simply use the RB25 numbers.

Ever so true, the unforseen stuff always bights you.

Cheers

Gary

All very good and well....but me and many others will see far higher costs doing this. Cheap china inlet manifods that need their flanges machined, nbew cool pipes, throttle cables, plus other mods to fit all costs hundres of dollars by workshops. If you are an R32 owner going RB30 you dont have all the gear off the front of the RB25 for belts etc. The power steering brakcet needs to be modified...none of it is overly difficult in isolation but unless you are a budding DIY guy i sense too many people make out as though this is an easy anc cheap conversion. Things like having enough flex in pipes to me is a receipe for popping cooler hoses for the rest of time...you having the smarts to get thigns to work and what other can expect as a result are a little different.

Anyway, my only comments are not to deter people, but just a word of caution that this no small feat. Especiually gettting a car through rego...re-stamping blocks isnt exactly a done thing

[bubba]

I set mine to 6800rpm just to be on the ultra-safe side with my setup, can't even get there with the little turbo yet.. dies in the ass just before 6000rpm

[Simon-S14]

what size turbo bubba?

[bubba]

It's a s1 rb25 turbo, goes from 245rwhp at ~5800rpm to 90rwhp by the time it hits the 6800rpm limiter