C110: RB20 or L28?

[Alfadog]

It's quite interesting with these cars - we have one RB25DET conversion going on, a V8 monstrosity project, an SR20DET in the US and already one C110 converted to RB20 with triple webbers, among others... Quite a few different choices people have made!

My engine is the original L24 still, and while it certainly sounds the part and goes alright it is getting a little tired and smokey. I'm on the verge of getting a full-time job which will change my lifestyle significantly and as such I don't really know what the future of my car is right now. What I do know is if I do get to keep it, I'll be swapping a different engine in.

So I'd like to hear what you guys' opinions are on this. Obviously you've all chosen your engines for various reasons, but why? What do/did you hope to achieve? And for those without a conversion, what's your opinion?

Personally, I think it's between an L28, RB20DE or RB20DET for my car and budget.

L28: It's period! Pretty much the same engine as what the car came with so a lot less fiddling around with engine mounts etc. and less hassles getting it legal. Cheaper, and has that "old school" sound. Expensive to build any great deal of power out of though, and as it's already pretty old it will need a rebuild. Cheaper and easier to fix if anything goes wrong though.

RB20DE:As much as some triple webbers would be fantastic on the side of an RB20 engine (perfect replica of the S20) I just don't think it's worth it for me. A fair bit of money to be spent converting from EFI to those exxy carbs and you get worse economy and reliability. So I'd stick with the EFI. Non-turbo engines are cheap nowadays and make reasonable power (155HP*). A fair bit of modifying to do though... gets expensive and then you have to ask yourself - why not just go that extra step further to RB20DET?

RB20DET:Probably a grand more than an RB20DE halfcut, but with an extra 60HP* stock it is arguably worth it. But the cost does not end there as you need to fabricate intercooler, buy boost controller, etc. etc. and of course, means more things to go wrong. Turbochargers are going to be about 15 years old now...

So what do you think? Any opinions on these engines, or others??

* Sourced from http://en.wikipedia.org/wiki/Nissan_RB_engine

[v12horse]

I think you know my opinion on this. Please, no Rb/SR swaps!!! That engine is a dog compared to a worked L-series. Yes it is cheaper to do the RB swap than to get more power out of a L-series, but I feel that the L-series is a far more superior engine in many ways.

Pros to L-series:

1. Extremely durable and reliable.
2. Has superior potential. The N42 block (L28 in 75-76' 280z) is known as the "Mania" block and can be bored out safely to 3.1L. With tripples, this engine has the potential to be a streetable 300-330bhp. The L-series has more potential than the S20?!?!? The S20 is for gentlemen, while the L-series is for the wild men. Sorry for the poor analogy.
3. Sound baby
4. Old school cool
5. The car will be worth more with an L-series than with a RB.
6. Easy to source parts.
7. Will last a long time.

cons to L-series:

1. Expensive to get power out of. (as you mentioned)

Before I type anything else, I apologize if I offend anyone, but this is only my opinion on RB/SR/V8 etc. swaps. These engines bastardize the cars. The car's have lost their identity when these things are done. If we ever want Z's/Skylines to get the recognition they deserve as classic automobiles, customizing them with engines swaps (even nissan parts) is not the answer. In Japan, engine swaps are not common among Z and Skyline owners. They are much more conservative, thus preserving the essence of their cars.

However, each person does have a right to do what they want with their car. I am not going to tell them otherwise, and I can still appreciate these-type cars. I understand that we all have different ideas of what we want our cars to be and there is nothing wrong with that. I know you have been on the fence with this Lachlan and here is my answer to your question. I hope I did not offend you (or anyone). I agree to disagree.

-Ben

[Mr Camouflage]

Hi Ben. You seem to be misinformed about the RB series. Physically, they are more durable than the L series and cant stand alot more HP being put through them.

Also Point 6 is completely wrong from an Australian point of view. We've had RB engines since 1987, so parts for RB engines are cheaper and easier to source than L series parts.

Alfa: If you are after horsepower, forget the RB20DE or DET. Sure the turbo can make some power, but you have to increase the boost to get it, but you end up with a laggy engine - not alot of power down low and heaps at high revs. Aslo when you start messing with the boost too much, you have to modify the engine managment computer (piggy back units that modify the signals from the engine sensors), or go with an aftermarket computer, plus spent money on the dyno tuning it.


The Rb25DET is a better engine and the extra capacity means it has to work less hard for the same HP that a 2.0 would.

Rebuilding an engine will cost $$$ nomater what the engine is. Most of the money spend will be in labour costs. Turbo engines will cost more because of all the extra stuff you have to add to them.

As for the L28, it has cubic inches going for it. Raise the compression a little, and have the head ported and polished, extractors. Use EFI for reliability and economy.

I'd go for the L28, and spend the money you would have spent on fabricating engine mounts, intercoolers, and all the other costs involved (eg engineers inspections) , on the engine itself.

It's period correct, wont require engineering to be legal.

Wont be as economical as a 2.0 naturally asprited engine, but will be alot more fun.

Another alternative would be the RB30E (VL commodore, Australian built R31 skyline). It may have to be engineered, but the 3 litre capacity and the fact that you can bolt one an RB25 twin cam head for improved breathing, and the availability of engines and parts (relatively cheaply) mean that its an engine to be considered.

Builting an RB30DE would be easier and probablyt cheaper than building an L28 3.1 stroker.

Or you could built an RB30DET, but i'm guessing that a bit out of your budget.

[blue_leaf]

Pros to L-series:
1. Extremely durable and reliable.

Sorry Ben but I wouldn’t agree with you there. I have never heard of L-series engines pushing over 1000hp, but have heard of RB with 1200+hp. L-series blocks are definitely very durable, but they were never designed for racing (s20 engine was meant to be THE racing engine and as far as i know no-one in Datsun was thinking of using L-series as a racing engine having acquired a twin-cam design from Prince, you are welcome to correct me here if I am wrong ) until the F54 block came. It certainly is true that L-series is a very potent design but the rarity of twin-cam heads lowers its potential immensely in my eyes.

Also as was mentioned above here, in Australia, we have got RB30 engines in R31 skylines which are getting very cheap now and having been sold in very high numbers (together with a twin model being a local Holden Commodore VL) parts are very easy and cheap to source, definantly easier than L-series parts.

Out of the engine that Alfa has mentioned above I would definantly chose the rb20det - you can get an engine under 1k nowadays with everything you need for conversion and gearbox can be used from local a skyline.

On the other hand I would personally build a an RB30DE with and RB25 head - that will sound great, have more torque than an L28, be cheaper and more unique than L31 stroker (with easy parts availability), and potential for future turbocharging.

Good luck with the car whatever option you choose.

[sakijo]

RB conversions are certainly getting popular here in Japan, especially for Hakosuka Skylines (see my friend Ito's web site). I personally would go with the L28 option. Less hassle and proven build ups. There are even books on how to upgrade and modify the engine for more performance. I like to work on my car, so EFI doesn't cut it for me - I need carbs.

Consider the market and the rego rules. These are the driving factors in whatever you choose to do. No sense in trying to build an engine if the parts are difficult to get or exhorbitantly priced . . . unless you're building something of collector value (S20).

[Gav240z]

Hey Lachlan, I loved your car when I saw it in person and I didn't even see the engine compartment.

I know you just went through the hassle of converting to manual so based on that I'd say stick with the L-series. You can get a cheap one from a wrecker give it a port polish, use flat tops and install a moderate to wild cam and she'll go alright.

However the economy of the engine won't be great compared with more modern EFI and smaller capacity motors.

Believe it or not I think an SR20 would be a cool swap. It's light can easily make good power and doesn't cost a packet, plus it's so easy to fit in .

In all honestly I've been tempted to do something like that with my Z. Yes I'm very much like Ben a die hard L-series guy but to build a 300 + HP L-series takes alot of time/money and research.

If you want drivability, economy, power and something light the SR20 is by far the best choice IMO.

I think the RB20 is a waste of time and the RB motors are heavier than the L-series.

RB25 head on RB30 block would be a good swap but your loosing economy then.

[v12horse]

Hmm... I don't know what to say or feel about what I have wrote on this topic. I feel that I was very harsh and narrow in my original post. I try to be as kind about my statements as possible.

This is what I would have wished I said:

The engine that one chooses for their classic Z or Skyline is up to them and it is a personal preference on what they want/need the engine for. Like many of you have said, the RB is easier to source parts for in Australia. There are also many other positives/negatives to this swap as there is for any engine rebuild or swap.

I feel that I should leave my strong opinions to myself and express my passion through my car and not through brash statements that may offend others. I respect all Zcars and skylines, wether they have an RB/SR/v8/L-series etc... I am just excited to see these cars in person no matter what style or condition they are in. We are a club here and I was not being a club member in what I said earlier.

-Ben

[v12horse]

Sorry Ben but I wouldn’t agree with you there. I have never heard of L-series engines pushing over 1000hp, but have heard of RB with 1200+hp. L-series blocks are definitely very durable, but they were never designed for racing (s20 engine was meant to be THE racing engine and as far as i know no-one in Datsun was thinking of using L-series as a racing engine having acquired a twin-cam design from Prince, you are welcome to correct me here if I am wrong ) until the F54 block came. It certainly is true that L-series is a very potent design but the rarity of twin-cam heads lowers its potential immensely in my eyes.

I have not heard of a 1200hp L-series either, but that would have to be a twin turbo. What about a N/A RB vs. a N/A L-series? However, I have heard of a S30 in Japan that runs an L-series with 50mm Mikuni's that can do the 1/4mi in 11.2 seconds. That is I believe the fastest Z in Japan.

I know the S20 was a racing engine and it made the Skyline/Z a winner in Japan, but I don't feel that the L-series was as down played as you mentioned. True the S20 has the higher technology, but it does not have the displacement that the L-series does. Without that displacement you can not get the same hp numbers out of the S20 that you can a L-series. If there was a 2.8L or 3.0L S20, then it would be much different of a story. When the L-series is mated with the LY head, fuel rail, and all the other bits that go along with this amazing engine, it has great potential and it was proven as a race engine both on the track and in rally.

I really don't know enough about many of the engine specs, capabilities, and history. I am not a good one to talk or debate about this with. I am always willing to learn more and if you or anyone has more insight on this, please explain.

-Ben

[Alfadog]

May I just say thank you so much to everyone who has replied so far. It is a really interesting topic I think, for all of us to talk about. If anyone else has some alternative views or other information please don't be shy!

Ben, do not regret anything. Opinions are what make this place work - sometimes the loudest are not always right. PLEASE do not keep your opinions to yourself. People can disagree with you, so what. I started this topic because I wanted to hear what people had to say, and I appreciate your comments.

For what it's worth, I seem to remember seeing a 800-1000 HP L-series engine. Maybe someone could confirm that? It isn't really the point though I know. They are both very strong engines. But if you are going to talk about strength, then why not bring the Toyota 1JZ to the table?

I will post a longer reply later!

I'm surprised no one has said anything about a Nissan or Toyota V8 yet though...

edit: My reference to the 800HP L-series engine was probably out of that same car you speak of, Ben. Do you remember the output figure?

[NZeder]

Lachlan I like you thought long and hard about what I was going to do with my RS30 with regard to what would grace the engine bay. Idea's I researched (all including costing out the project)

1. Nissan V8 - both 4.1 and 4.5 (my understanding is that the 4.1 is slightly narrower and would fit better but if you want the 4.5 you can stroke the 4.1 to 4.5)

2. Next I had a good hard look (for 12months) at building a quad rotor or a 26B (2 x 13B on a custom shaft) for a 500+ HP NA engine. When I win the lotto I might do this but not in a Zed maybe something else

3. RB engine looked into - both DET and DE. Personally I like NA (well never owned a Turbo so can't really comment but they go like hell ) so this left just one other option

4. L6 3.1, 3.0, 2.9, or just a 2.8 (did not want a 4 cylinder as IMHO both the Zed and Skylines were first inline 6 and that is they way they should say - don't get me wrong I like the 300zx/350z and R35's but Nissan designed the original cars with inline 6 so it should have one it in)

Anyway I have gone the L28 path as you know. My reasons

- easy just drops in (worked or not easy install I can do that myself)
- weight no weight change unlike a RB engine install = I am not automotive design engineer so I assume Nissan got it right 30+ years ago and I assume many of us agree otherwise we would not love the cars so much.
- it has the old school feel + I love the sound of a L6 when rev'n
- legally we can only drive at a maximum of 100km/h here in NZ (60mgh) so having a DET would = loss of license and maybe even the car.
- my car will be a road car first and might just go around the track once and a while = 3.1 out (love the idea but gave my LD28 away so I would not be tempted to keep thinking this way).
- I have triple TB for the engine so result = old school with a touch of the new (the IT guy in me wants to play with EFI and a mega-squirt)

so that is were I got to in the end - I will be putting in a stock L28 that I have to begin with while I get used to the mega-squirt etc (plus to iron out any bugs etc after a complete rewire of the car) then I will use either the other F54 I have and put my worked E88 on with a set of L24 rods and custom forged flat-top at 87mm or build the N42 I have as a 3.0 with Kameari rods and pistons

so my opinion if it counts go L6

Cheers
Mike

[zedevan]

i was thinking of replying to this thread with "y not use a 1/2jz", in about a year when i have more money (and am off my p's) this is the swap i'm currently looking to pursue, most likely 1jz due to price and still want it to be semi fuel efficent, but then i guess to produce the power no matter what engine it is, besides the different ineffiecenties it still has to receive the same amount to be able to produce it

i was therefore thinking a 2jz with a 6 speed would b nuts, as then for freeway type driving the torque and 6th gear would work out good, but the price really bites, so i think at some stage you have to remember if the aim is to save money and therefore use a more fuel efficent motor, at some stage the cost of doing it should be concidered, a perfect example is my mate who's putting a k20a into a crx...huge waste of money, but the rising price of fuels and my desire to do an engine swap was making me think of an rb20 or sr20, and if the sr really is heaps better, which i guess it is since they didn't kill it off, i'd just be an issue of getting the mounts here in aus

the other problem with like a 2jz or other rediculously powerful engine is the bracing that would be needed so it doesn't bend the whole frame, so therefore atleast at this stage i dont think i'd want over like 250kws, and while this might be possible out of an l28, if i ever wanted more i'd b stuck, where as with the newer ones, rb or whatever, there's a huge room for improvement should i ever get bored

for its price i reakon the 1jz seems to be the go, but then there's the whole toyota in a nissan thing, my thought is that since the concept before 240z's was powered with the help of yamaha, and parts of 1jz's are also, then it all works out! i wonder how much a vvt-i 1jz gte is...and since ppl put the 2jz block on their 1jz's to make the same sort of rb30 hybrid thing with their 1jz's without having to change over the head i guess this would always be an option, and would mean the supra 6 speed could also be used? but the manual gearbox's seem to b more than the engine is! but there's that possibily of the older gearbox that the one in syd (now in england) car did

i think thats about it, hope i make semi sense...the 1uzfe also seems like a great engine, specially supercharged, although it costs heaps, and the 1jz seems to be the winner with soarer owners!

[aarc240]

Have you thought of just adding a blower (supercharger) to an L6?

Inlet manifold doesn't even have to be anything special, a modified stock 240k works fine on the street. You can even use a stock exhaust manifold without losing too much (just use a big bore system, 2.5" or bigger).

A bonus is if you pop a motor through too much boost or having too much fun you can just drop in another almost stock motor. There is nothing downstream of the motor to get written off by the debris unlike the exhaust side of a turbo.

Smaller blowers are easy to get and cheap. If it doesn't produce enough for you, change the drive pulleys to spin the blower faster.

Apparently the blower from the Toyota 2 litre engine is good for around 8000 RPM (rotor speed) without alteration. That's about 25% overdrive and I'm pretty sure not too many 2 to 3 litre engines are going to stand the resulting boost for very long, regardless of manufacturer.

[g72s20]

I think for your situation Alpha, keep your eyes open for a fresh L28. I have no idea what the performance potential is of the NAPS, was this a change for emissions sake? Or can it actually be made to get the L6 to lift its skirts and run? As you say, triple Webers will always be expensive. There is a lot of potential in the twin su/hitachi's evidenced by the various class racing that demand these on the Z's. Maybe put some dollars into the set you have for a warm 2.8? If you are budget concious (and who isn't?) you don't want to build too much horsepower into your car because you have to be able to reign it in and control it as well ....bigger brakes, better suspension, the rest of the drive train from the clutch back. How much can the original bits take? All adds up to lotsa money.
A nice clean L28 with fresh carbies or tricked up injection (anybody know anything of the performance potential of the NAPS?)...extractors into a twin system purely for the sound to match the looks! A mild cam...I reckon this would keep you happy without breaking the bank so you could keep the car long enough that in time your new job will be able to finance that engine change (and all the other mods this would demand) of the future to whatever your heart desires!
Personally,eventually I want to see a twincam crossflow NA six with "adequate" power in my KGC10. It's a way off yet so I guess in the mean time I'm doing just what you are, seeing what's out there and just what it's going to take to get what I want.

below is my idea of "adequate" 237PS S20 care of Shiraishi Engineering Japan.

[Mat Big Hat]

The RB-S30 swap is increasing in popularity. It's newer technology and looks pretty cool as well. Many of these z-hybrids are purpose built street/drag cars. The extra weight affects road course and autocross handling, but has less of an effect on a straight-line car.

An RB-KGC swap would be a good choice because the Kenmeri is rarely a purpose built track car, rather a GT cruiser. The twin-cam cylinder head hearkens back to the original "R" spec models without the fuss and cost of an S20. The modern induction is functional and efficient, but triple sidedraughts would blend an interesting combination of old and new technology, even more of an homage to the S20 R spec, especially if combined with extractors.

The SR-S30 seems to be better suited for track use for obvious reasons, so it'll be interesting to see how much of an improvement the SR swap is to the handling of the KGC.

One thing that hasn't been mentioned is a Cedric/Q45 V8 swap. Plenty of room under the bonnet of either the S30 or KGC, lots of grunt and growl, potentially better weight distribution, and still a Nissan product for the purists.

[Mr Camouflage]

The NAPS (Nissan Anti-Polution System) intake manifold has a twin throtle valve, One main one, and one slightly smaller than the other. The Plenum is larger than the other efi manifolds, and the runners are about the same diameter.

NZedder will be able to tell us more, as he has one.

I think you have to replace the throttle body with a single valve throttle body for better performance.

[Cuong Nguyen]

[QUOTE= RB25 head on RB30 block would be a good swap but your loosing economy then.[/QUOTE]

not sure how much truth there is in that! i would have thought that with a more modern cylinder head that the chances of getting better economy would increase if the tuning is spot on.

of course economy goes out the window if the right foot is heavy on the pedal...

personally i wouldnt bother doing the whole RB conversion for the RB20 as they do not have much torque, lots of work for not much gain. unless you are prepared to go RB25DET or bigger then stick with L28.

[240K&Beyond]

Hi Lachlin,
Knowing budget contraints, I would go down the "bulit it up" slowly path. Myself, always the L28, unless I had a spare RB26 lying around, and who does?
My old K coupe had a L28...R motor in it which I bolted a T3 hair dryer to with an extra 80Hp injector system. Running 6 PSI, two head gaskets and no intercooler, I was puting out 350HP at the rear wheels. No matter what I did to the diff and suspension, I couldn't stop the back wheels from spinning in any gear (including 5th) There was nothing better than crusing around at 80 to 100 kms and dropping them hammer next to another car, bagging the rears and taking off with two trails of smoke. Chasing any more power would be life threatening !
But back to the subject at hand, I have checked with Vicroads and the NSW RTA both say that you can drop a L24/26/28 Cary or EFI into a K without an engineer's certificate. Making things too easy. I assume the QLD RTA would say the same.
I have chosen to keep the "Old School" approach with the L28EFI. Although I am planing a toyota supercharge, T3 turbo charger hybrid later down the track. Built for torque and quick response. You get the car registered quickly and easily with the L28 engine number and insurance companies can see the car without "hitting the roof". Then build it up later and the engine number still matches all records.
Personally Mate, look for a 1983 280ZX manual car. They have the F54 strengthened Block and the P90 Head with larger valves. And a manual EFI system which will wire into your car with only six connections. (I have the EFI docco if you need it) I bought one off ebay registered for $1100 AUS a year and a bit ago. Stripped what I needed and dumped the rest.
This would give you an good starting point to which you could decide where you want to go: Further EFI work, Turbos, Superchargers, Triple carbys - whatever.
And at the end of the day, when you lift the bonnet of your old school skyline, you don't have a face full of techno. Just something that looks original, however tricked it may be.
This is my preference and opinion - I don't mean any offense to others.
Keeping it Simple ;-)

[blue_leaf]

My old K coupe had a L28...R motor in it

Whats an L28R motor? or is it just a typo?

Running 6 PSI, two head gaskets and no intercooler, I was puting out 350HP at the rear wheels.

Anyway 350 Hp on 6 psi and with no intercooler?!!! wow, thats a great achievement! Give us more specs -turbo specs, head, intake/exhaust manifold did you use? What sort of compression did you get by using twin gaskets?
Also what car used P90 in Australia? I was under the impression that they were never put on Aussie cars. Do you have a P90 that you might wish to part with?

[aarc240]

What sort of compression did you get by using twin gaskets?

Pretty close to 7.6:1

[aarc240]

The NAPS (Nissan Anti-Pollution System) intake manifold has a twin throttle valve, One main one, and one slightly smaller than the other. The Plenum is larger than the other Edi manifolds, and the runners are about the same diameter.

NZedder will be able to tell us more, as he has one.

I think you have to replace the throttle body with a single valve throttle body for better performance.

The plenum might be bigger but the flow bench shows uneven airflow distribution to the cylinders when fitted with a single plate throttle body.
I've got one of those things too and it is a pollution 'fix' not a performance device.
Like NZedder I'm going with a modern ECU. I think his plan is a MegaSquirt, mine is a MicroSquirt (very little difference, conventional components vs SMD). Don't know what ignition NZedder plans, mine will be crank triggered Ford EDIS.
Single plate throttle body is so that a Throttle Position Sensor will give sane output throughout the movement range, nothing to do with performance.
I've now junked the NAPS and switched to a 'normal' 280zx single plate throttle body injection rig.

[aarc240]

For anyone keen enough:

http://cgi.ebay.com.au/ws/eBayISAPI....ADME:B:SS:AU:1

BUT there are no injectors, fuel pressure regulator and a few other bits you will need.
btw, injectors on a 280zx (OZ release) and an RB30 (VL Commodore or R31 Skyline) are the same parts!

[Mr Camouflage]

There were a naps manifolds on ebay.au and ebay.com about 1 or 2 months ago. The one in Aus was listed at $75 and had the fuel rail and injectors, the usa one didnt and was listed at $300.

I've been told to use the non egr N42 intake manifold for efi + turbo from someone that has the same setup.

[aarc240]

Not sure where you'll get a non-EGR manifold in OZ - we didn't get EFI until after July 1976 when EGR became a mandated requirement under the ADRs.
Apparently these non-EGR manifolds appeared on '75 280Z US models.
Not a problem, just cut the EGR extension off the manifold and have a plug TIG or MIG welded in. A quick buff over with an 80 grit disk smooths it out and if you are fussy, a 320 grit disk will get it neat.
There's no reason you couldn't have the EGR valve there and mounted with a stainless steel plate under it - be pretty hard to get EGR working then!
btw, the NAPS manifolds I have looked at have nearly all been L20E import or L24E (R30?) units and the injectors are NOT adequate for an L28.

[NZeder]

I no longer have my NAPS manifold - but as others have stated the plenium is larger and the twin butterfly thing. My NAPS manifold came from a L28 - I have not seen a NAPS on a L20aE yet (which means I have not looked hard enough). Re the quesiton about my ignition plans - I have 6 L20ET/L28E CAS dizzies (Yes the later L28E fitted to 280zx JDM have CAS systems - my NAPS engine has one but the dizzy is empty just a rotor as the CAS is a pick mounted to the block with a toothed wheel behind the front pully/balancer all Nissan kit) so I plan to use this setup to begin with. I am going with EFI Hardware Triple Throttle Bodies (from Speedtech in VIC I believe) for a bit of the old school look but with modern tech + I love the sounds triples make and I have not seen too many setup's like this here in NZ on a Zed (I know there are of 1 race car L6 engines getting built but this will have 50mm triple TB and be one hell of a 3.1 stroker going into a HS130/280zx 2 seater)

I do like the idea of a RB with triple's be it carbs of TBs. Here in NZ like OZ there are lots of VL's RB30 around and they can be picked up from nil to a few hundred dollars. However I personally would not put this into a S30 - however we are not talking about a S30 now are we as Lachlan has a C110 which has a different body/weight layout so the extra weight in a RB might not be an issue. Whatever you decide Lachlan I would love to see it say a in-line 6. Given how your cars looks externally don't do a SR20 or V8 (again this is just my opinion) it will spoil all the good work in making a GTR rep on the outside. If you want a SR20 or V8 conversion get a 510 for SR20 conversion and a C330 for the V8 (I thing a Nissan V8 in a 260C would be very cool but to be the badest 260c with a V8 it would have to be the 2 door hardtop version )

Cheers
Mike

[NZeder]

Re the NAPS intake thing - if I was going to keep this I was going to install a 65mm TB to replace the twin butterfly setup and remove/weld up the EGR. There are a few non EGR intakes here in NZ (NZ new cars only as the JDM have the EGR) as we did not have any polution control requirements until just recently (not sure if we have any standards at all just that all new cars now have it fitted standard not sure if this is a local legal requirement or just because that is the way they come - anyone else from NZ confirm?)

[440k]

Lachlan - If I were you, I'd stick to a warm L28. There's a guy in Brisbane who builds lots of hi-po L28's, and he's a darn sight cheaper than any of your big "tuning houses". This guy mainly builds for the rally / race crowd, so builds stuff that works (without the fancy stickers to go on the side of your car)

Harry (the guy I bought my car from) knows this fellow, and says he makes excellent cheap horsepower.

I tend to agree with many of the other sentiments. Whatever you choose, it HAS to be an L6, and HAS to have 6 throttles (whether that's by way of triple side draft carbeis, or 6 EFI is up to you). The L series is bullet proof - for a sweet driveers engine, you can't go past the crisp throttle response of a well sorted N/A

Turbos are nice for the mid range rush, but you can't beat the feel of an N/A (my personal opinion)

I also agree about the "bastardisation" of the 240K. Hypocritical coming from me, I know (pushrod boat anchor nestled between the front guards in my car) but that's more of a "let's see what we can achieve with wha's already there". When I want to get serious with it, I'll probably go back to the L28.

[240K&Beyond]

Potential Hijack Alert: The L28 R
No John (Blue Leaf), It's not a typo, It was a very special engine that came out of a 2 door R30 vintage Skyline that was personally imported from South Africa. It was around 1990 so my memory fades a bit. I cannot remember if the engine number was L28XXXR or L28RXXX. Where XXX were the numbers.

I didn't think anything of it when I bought it 2nd hand off the guy that imported it. I also bought an L20A turbo motor and a 2nd hand T3 Nissan Racing Turbo. The plan was to put it all together and teach myself about EFI systems.
The guy I bought it of "Simon G" had just started a garage company under his parent's house called "NisPro Performance" which is now quite well known in Melbourne and Oz for making some pretty silly engines. I think he was the 1st to pull 1000 HP out of a RB30 and for that matter the Ford BA4.0T engine.
Anyway, he said that the motor used to beat allot of V8's around in it's stock form in the 2 door coupe. I took it with a grain of salt, bought the bits and went home to construct my new 240K heart.

At that time intercoolers were at least $1500 so it was not an option. Knowing this I went down the "Low Pressure" Turbo, "High Pressure" Cylinder path because at lower boost pressures, the air into the engine is cooler and does not need an intercooler.

The advantage to Low/High is that you get quicker spool up times, better low down grunt (engine rev wise) and neck snapping acceleration. However, the disadvantages follow that: You need a very strong bottom end of the motor, there is more potential to achieve predetonation (pinging) and a few other nasties. Consequently, Most car manufacturers go down the High/Low path using an intercooler as the result is more driveable, safer, and there is less risk to the engine. It's probably cheaper in the long run too.

So, keeping all that in mind I wanted to reduce any air restriction both inward and outward of the motor. Off went the head and down to a head specialist to port, polish and put bigger valves in. I was confused when I got the call from the specialist asking what I wanted him to do as the head already had the biggest valves in it he had ever seen. And the funny part was they were all stamped “Nissan” WTF ! He tested the valve springs and said they were good for around 7000 RPM and were as good as what he was going to put in. So I got the port polishing done as he said he could not grind them out anymore than they were already quite large.

I jumped on the phone to Nissan’s Head Office and asked if I could get the specifications and possibly a manual for my L28R engine. This was when it got interesting; They said they have never heard of such a beastie. I asked them to follow it up further. Two months past when they returned with an answer, well actually, it was a question: Where Did You Get This Motor From? I explained the history to which there was a long silence at the other end.

The Engineer at Nissan Australia’s Head Office explained that this engine was in fact a racing motor and that’s what the extra R in it’s number meant. It was a limited release and should not be in the country. Yes, they were release in South Africa as there laws were more relaxed.
Apparently, the engine had the larger spec’d head, a fully balanced crank, larger bearings and flat top pistons producing 10.5:1 compression. Needless to say, I got off the phone and jumped in the air for joy.

I quickly put the head back on the motor using two head gaskets to lower the compression down to 10:1 and bolted the turbo and all its bits on. Spent two days tracing out the EFI wiring loom and wired it into the car.

The first time I took it out on the road after the exhaust was installed, I was happy with the acceleration as it seemed a completely different world to the original carburetted 2.4 litre six. However, it started pinging at 3500 RPM and ran out of fuel at 4000 RPM.

Needless to say, my learning curve had only just begun and there were plenty more tricks to learn in building an EFI Turbo Motor. But I have been crapping on for ages now, if you like, I can explain some of the tricks later.

Just out of interest, has anyone else heard of, or experienced a L28R? I would like to know more about there origins, were they were release as Nissan Australia really didn’t want to talk about it.

Miles (Sakijo) in your travels, has anyone ever mention them?

[Mr Camouflage]

not sure how much truth there is in that! i would have thought that with a more modern cylinder head that the chances of getting better economy would increase if the tuning is spot on.

of course economy goes out the window if the right foot is heavy on the pedal...

I think he meant loosing economy compared to a RB20 if you built a RB30

[g72s20]

...AArr Good on ya Bruce! you've got me well and truly hooked on this L28R thing. Just where is that engine now, hmmmm?
I'm off to check out South African Datsun sites now!!

[sakijo]

Never heard of an L28R. Another interesting topic. Japanese might have something on it. Suggest moving this to a new thread before we totally hijack it.

[240K&Beyond]

I have opened up a new thread.

Sorry Jim, I have already been there without result. Google SA is a very hard thing to deal with.

Unfortunately my old 240K coupe died with the engine in it. A bloke "T-Boned" me which pushed me off the road into the back of a parked 10 tonne truck.

I recovered the engine from the wreck, but never got it running again. It was eventually sold with a 240Z I had at the time. I lost track of it then.

[240K&Beyond]

Lachlin, back to your original question and my comment, If you plan to go down the L28 path. You should look for an 81-83 280ZX manual car. These have the F54 Block and the P79 head. Have a look at the following:

http://www.geocities.com/zgarage2001/engine.html

[NZeder]

Lachlan, re the F54 thing - there are two stories out there, some say the F54 is the best block to use as this is the later type etc, well I have both F54's and N42's and the research I have done does not show the F54 as a better block. Most of this F54 stuff comes from the US where they got the L28 before we (as in AUS/NZ and JDM) did. I believe there might be two types of N42 out there, the first one, ie the ones used in the 280z = US spec, and then the later units used in the 280zx before the F54. If you are planning to stick with a stock bore size then the F54 is a good choice. If however you want to build a big bore L28 use the later N42 block as these too are a siamesed cylindered block but the water galleries are not as large = bore bigger (I believe others have done sonic testing on both blocks and can confirm that the N42 have more meat for over boring). I believe the water galleries were changed for extra cooling in turbo applications (given the F54 was the turbo block also)

I have also found that most of the Japanese build 3.0 and 3.1 use the N42 blocks so this might also suggest they are better suited to this application. I once found a Japanese site that would build a 3.0 on a F54 but stated that block filling was required (got lost in the translation but I think this was again talking about the water galleries and the lack of cylinder wall after a 3mm over bore) also escort (a piston make in Japan see http://www.escort-jp.com/) only shows a 88mm piston for the F54 block....hmm all this starts to tell me that the F54 is not a good as it is cracked up to be (well this is my research and opinion)

So while other are hunting down F54's go an pick up a few N42 for cheap while you can if the L28 is the path you want to go.

Just my 2c on the F54/N42 thing - again sorry for the slight hi-jack.

Lachlan if money was not an issue I would track down a S20 and build the almost perfect GT-R replica however given the thread question we can assume that will not happen (S20 do come up on yahoo.co.jp from time to time but more $$ than you and I would want to spend unless we won lotto but then we would just purchase a real KPGC110 and be done with it ) and as you know there are a lot of JDM GT-X with the L28 treatment and a few with the RB20/25 and triple carbs. Re the RB2xDE (not the DET's) from what I have been told by an engine builder locally you can't get a lot more over the standard output without spending a truck load of $$ which does not justify the gains. This engine builder said if you want power from a RB it must be a DET not a DE. So it comes down to this - what do YOU want? Lots of power? a DOHC? Turbo or N/A. So if you want DOHC then you have just one (Nissan that is) in-line 6 and that is the RB series. If you want power then how much $$ have you got and what is the best bang for your buck (don't forget any engineering that might be required if repower is the choice). Then if talking N/A what type old school carbs or EFI.

You have a lot of choices - I know I have been though them all myself.

Whatever you do I am sure you will be happy and the quality will be great just like the work you have done on your car todate.

[440k]

I'm on the verge of getting a full-time job

Congratulations, mate! Is it a definite, or still "in the pipeline"?

Hope all goes well. If you need somewhere to store the K, I'm sure there are plenty here who'd help you out

[khughes]

woops, i missed this thread.. and i guess i should put in my opionion, i have to admit first up that i have taken possibly the most windy (and most probably costly) path to my goals, and i still have quite a way to go

i wish i was a lot more logical in hindsight, but at the time i knew little about the engines involved (not much has changed and the whole modified car process

to summarise i guess:

• L28: sound is #1 simply awesome! i chose not to upgrade to this probably a little out of ignorance, and because i know nothing about carb'd engines
• SR20: close! it's a nissan, but no skyline heritage!
• RB20 (NICS): tried it... i came to the conclusion that if i was going through the pain of the conversion, i may as well do it properly
• RB25: skyline heratige, 6 cylinders!, noises in all the right places, plenty of power, similar weight to the L24, plenty of parts available
• RB26: too $$$... spending 2x on the RB25 was obviously a better move

Why did i go down the RB25DET path? well... the answer is pretty simple... i owned an R33 GT-R... and they are very very addictive!

The skyline bug bit me so much so that i decided to build up a 240K into a GT-R replica as they were extremely rare and nobody in the SAU community (life and blood of Aussie skyline enthusiasts!) had really gone down the classic skyline path (well... before the R31) except a few rare cases.

I couldn't justify $6.5K for an RB26DETT, and that was without a gearbox! (little did i realise, it probably would have been much cheaper for me to go down this route!) and meanwhile there was a HUGE thread on SAU about the RB30/25 hybrid, and that captured my imagination! An RB25DET +box was around $3k, and aftermarket parts are a LOT cheaper (except injectors!). The thought of an SR20 just didn't site well with me.. sure they are a great motor, but it is a 4 cylinder (phhht ;D) and if i was replacing the motor, i may as well replace it with a genuine skyline heart!

well.. my plans deviated here and there as the plot thickened, originally i got my hands on an R33 RB25DE and a bought a $100 RB30E block out of an R31 skyline.. ripped them all apart began collecting the bits for the hybrid conversion (it would have been so much easier and cheaper buying a half cut).... to cut a long story short, i decided to fast track my hybrid plans, set them on the backburner and get the car running with an engine. so i bought an RB20DET (NICS) and gearbox out of an imported R31 race car from ebay for $750

The NICS engine was in pretty good shape, and importantly had all the bits that i didn't have for the hybrid.. wiring looms, computer, small intercooler, AFM's, turbo etc.. and because the mounts were the same and the engine is of a similar size, so that would have been an easier transition.. so i started out up that lane... it didn't take long for me to realise though it was a bad move, as the gearbox was smaller, and the engine would never put out any power that i would be happy with (even until the hybrid monster was ready), so i took an oportunity to sell it again for the price i paid for it (minus the costs of refreshing the oils, belts, plugs and powdercoating the cam covers).

At this stage, i sort of came to the realisation that although common, the RB30 conversion would cause hassles for me down the track with engineering (and there is so much other stuff that needs to get through that i decided not to chance it, maybe one day i will bolt up the rb30 bottom). so I then decided to buy a full RB25DET + gearbox, it would give me most of what i would, it would be a good basis for as much power as i would want to put out (current goal is 300KW at the wheels), it was a modern engine with EFI (i sort of understand that!) and i could apply most of my knowledge and research from the RB26 on my GT-R to the RB25...

so apart from a Greddy intake to keep the engine low in the engine bay and a few "in preperation" upgrades (like greddy top mount fuel rail, nismo 700cc GT-R injectors, bosch 044 and R32 GTR fuel pumps, ATI harmonic balancers, RB26 water pump, Apexi ECU) i am trying to keep the engine fairly intact and concentrate on getting the engine in the car, down the track it will end up getting a bigger turbo, cam's, cam wheels etc... all stuff that can be used on the RB30

so my recommendation is to pick a power band that you want to achieve and how much you are willing to spend... be reasonable though.. the more power you have the more you need to upgrade, and of course the more traction you will loose.

pick one engine that you can upgrade later, and if it is an RB, get a half cut.. you will make life a lot easier when your trying to hook up all the emissions gear, and in the long run you will save money! RB25 and RB20 half cuts are getting very cheap now.. you can usually get half cuts for the price i would have payed for the engine alone 1-2 years ago.

an L28 will certainly be cheaper, no need to get mounts or driveshafts made up, no need to engineer the car (saving $500+) etc., and still some room for improvements, but not enough power to really affect handling or drivetrain

for a turbo RB you would certainly need to look into upgrade brakes, diff, cv halfshafts etc.. otherwise the car will be forever braking things

I can certainly see the advantages of the L28 having been in Jim's C10.. but i can guarantee you that an RB powerd C110 on full throttle will also be something very VERY special!

sorry for rambling a little...

[240K&Beyond]

When I turbo'd my L28, I broke 1 clutch, 1 gearbox, 3 half axles before the cv conversion, rear drums continuously, several demerit points and a boot load of tyres.

Hell Kent, I didn't realise you have just about fitted everything into a K.

Thanks for the input.

[khughes]

yeah, unfortunately for my bank balance.. i just wish i could get one of them finished!

[Alfadog]

Wow what a response. Thanks so much everyone who has had their input. I think it is a really great discussion that has really got me thinking. I hope it is beneficial to others too.

I agree with the majority here, that it's got to stay a Nissan straight 6. No logical reason, just that anything else would feel rude.

There is so much information here already, heaps of great stuff for future reference. It's probably a good while yet until I do anything, but it's always nice to talk and think about these things.

Peter (440K), nah mate it's in the pipeline, I had two final interviews this week and another next week, so hopefully at least one goes through. Then I'll probably be very busy with it - just hope I still have some "play" time, or worse yet, lose interest.

[73skyline]

well i went with the sr20det route as you all know. i know it may not have skyline heritage but its still a great motor, if i had RB money i would have gone RB. too bad i got offered a rb20det motor yesterday motor and trans for $250 US dollars, i might pick it up jus cus its cheap and have it in my backyard for future plans, also reason i went SR, my tuner tunes these motors so well and good parts availablity. if SR20dets are being used in skylines and 350zs i figure it would be cool in the KGC. im not looking for big HP numbers. with the new turbo i should be getting 400whp pretty easy which is way more than enough power for a KGC. i already driven a 510 with 375whp with SR20DET motor stock internals, super afc, ITC, 550cc injectors, z32 maf, t3/t4 turbo, i/c and some race gas and a very mild tuned ecu, basically limters cut. would have gone more power with stand alone ecu but thats next. as i move along in the conversion ill post updates, im happy how its been coming out and looks very clean.

before i did the conversion believe me it took a year to decide on what i wanted to do, weighed out all my options price wise and availability. since im here in the US sr20det parts were pretty easy to get, i thought about l28et, rb20det, rb20de with carbs, rb25det, sr20det, and ca18det.

personally building the car i wanted something different but at the same time worthy of putting in the car, i know the sr wasnt traditional but i tried my best to make the swap clean and look respectable, i want to have people see the car and motor and open their eyes to a KGC and what is possible, not many people know about KGC cars here,,all they know is the hakusuka box....whatever you decide on what motor to use just build it with love.

mikey

[aarc240]

if SR20dets are being used in skylines and 350zs i figure it would be cool in the KGC.

I know, off topic but an SR20DET in a 350z ???
I hope they put that sucker on a real serious diet too (the 350Z that is!)

[Mat Big Hat]

Well, the SR into the 240Z is a great combo for power/handling, so it should really help to resolve the nose-heavy characteristics of the LWB Kenmeri. So hopefully you plan on tracking or autoxing it to see how it all comes together!

[Kproject]

Hello everyone, i'm new to all this, this being my 1st post so here goes...!

I am also looking into an engine conversion for my 240k, personally i'm inclined to get an RB20DET because this engine should suit my prefernces for the car.

1: it's still nissan
2: easily daily drivable
3: strong enough for hard driving
4: loads of potential for upgrades from aftermarket
5: easy for parts and service

i hadn't thought of too many of the downsides that are previously posted so i think i'l probably dedicate some more time to research on it.

My research found that for an RB25DET froncut with R33 Gbox is roughly about $1200 to $1500 more expensive than an R32 RB20DET frontcut. (in S.A)
because i'm new at this i wanted to get a frontcut because i'm not 100% sure if an engine package will supply everything i need. and its only $300 more for the whole front end over just the essentials(engine,coolers,computer etc).

also i found that here in S.A we can put an RB30 into a 240k with out an engineer checking it and without any necessary upgrades. just ring up and tell the motor rego office the new engine number and they send you a new rego sticker. With an RB20DET theres brake upgrades, full inhouse inspection of the car, potentially even chassis strengthening and more. with an RB25DET i think it would just be more so again! even bigger brakes, stronger chassis etc. but really i want the turbo option so i'l probably stick with the RB20 an see how i go.

Is there anyone who has succesfully fitted an RB20/25 to a 240K and has a description or information on how to fit one? any help would be greatly appreciated!!

[khughes]

definately get the whole front cut ($300 is nothing in the scheme of things, especially if this is your first project), i have wasted a lot of money and time trying to chase parts because i just bought an engine and gearbox without all the extra bits you get in the 1/2 cut.

I can't believe that SA's RTA will allow you to put in a completely different series engine with a much larger capacity without an engineers certificate, let alone accepting what you say the new number is over the phone.. i would ring and check if i was you.

anyway, you will probably also need a custom mounts, driveshaft, upgrade to an R200 Differential if you can, and much better brakes.

The RB series sizewise, do fit in nicely (see pic), and as you said, the RB20DET will work out a LOT cheaper. then again.. you could do an rb30 with triple webers

[aarc240]

I can't believe that SA's RTA will allow you to put in a completely different series engine with a much larger capacity without an engineers certificate, let alone accepting what you say the new number is over the phone.. i would ring and check if i was you.

I think I did refer you to this publication before:
http://www.dotars.gov.au/transport/s.../vsb_ncop.aspx
This is NOT binding on any state or territory authority but in general is being followed pretty closely with the occasional adminstrative or terminology differences.
Have a look at NCOP3 Section LA and then talk to Transport SA.
An L28 is considered an 'optional replacement engine' and doesn't need certifying. I even have that in writing!
A standard RB30 just fits within the guidelines so again no certification provided there are no chassis / body mdifications made.
An RB20DET is a different ballgame and WILL require certification simply because it has a turbocharger.
New engine number over the phone - that's a new one on me!
Usual process varies for country vs city clients but requires written advice (a standard form). Next is inspection to verify engine number - SA Police if country, Transport SA if city.

then again.. you could do an rb30 with triple webers

Not in SA you won't (and very likely in any state or territory). If you use a 'pollution' motor like an RB30 then ALL the original pollution crap has to be retained. No way are you going to modify Webers to comply!!

btw, just about any 'performance' modifications WILL require that an L28 in C110 be certified with the sole exception of header exhaust.

[JMT240KGTR]

Lachlan,

Good to hear you may be keeping the car.

I tend to agree with those who suggest retaining the L series, whether it be L24/26/28, simply because you can make great street power & retain it's 'heritage' so to speak.

The best example I can cite is my fathers '76 240K sedan.
It had an L24 built by Gordon Dobie (Datsun Performance Centre / ex Datsun Team Mechanic I believe) and I can tell you this car was seriously quick.

From what I recall on capacity it was either bored or stroked to 2.7ltrs, high C/R, triple 40mm webers, extractors, and one serious camshaft .
It also handled like a dream.

It out-ran many V8's, and a few GTRXU1's as well, and was very quick & nimble, response was amazing.

If you're car is to be retained & street driven, the L series is quite tough & when you open the hood, you'll have some originality that people will say "damn, this old motor goes alright".

ps Don't forget Datsun's (pre Bluebird) best Bathurst 1000 performance;
7th outright, Datsun 240K, 1972 and in a standard L24....

food for thought

[aarc240]

Oops, got that wrong!
Quoting from reply from
Alan Whitaker
Coordinator Vehicle Standards
Vehicle Services
Department for Transport, Energy and Infrastructure Regency Park
"All you need to do is notify Customer Service (Motor Registration) of the engine change on the MR7 form with the new engine number recorded and we will send you out a new registration label with the number recorded on it."
Of course that is assuming the engine is a code LA1 replacement not requiring certification!

[aarc240]

Just gleaned a little more info on the F54 vs N42 block saga.

This is from some old notes scrawled in a scrapbook by a gent who used to be the top machinist with one of South Oz's best engine shops in the 60's thru to the late 80's, said scrapbook getting into my hands from his widow.

F54 will take a max overbore of 3mm, SOME N42's will take 4mm.

Total bare block weight is almost identical but the F54 is a little heavier at the rear of the block.

He attributed this weight bias difference to the F54 being the only L6 to have the reinforcing struts bolted under the back of the block and onto the front of the transnission. He noted that the lower rear area of the F54 was a thicker casting than the N42 but the water jackets were a little more open.

Curiously, he recorded an observation that the F54 was less likely to distort the cylinder walls when overbore was kept to 1mm and the engine was to be turbocharged. He noted that for an N42 overbored 1mm and turbo'd the owner was to be told it was 'not as good'.

Interesting related note was that those reinforcing struts are aluminium in 280ZX and 280C autos but steel in 280ZX manuals, 280ZX turbos and L28 powered Nissan Patrol 4WDs.

Makes you wonder whether Nissan just might have changed a fair bit in the block to suit the turbo application!

[matt240K]

I was considering starting a thread on this, but I guess this is the right place for it.

Notwithstanding people's opinions on whether its a good idea or not, I may be thinking of converting my 240K coupe to an RB30. Has anyone here done one, and how difficult was it?

gearbox?
Engine mounts?
Physical fitment? (eg does the bonnet still shut and the radiator not hit the fan etc)
anything else?

thanks in advance.

[240kingdat]

This is a very interesting thread, with some good information and stats! It stuck out at me, because I was very keen on doing an L28 in my c110coupe, but an RB25DET fell into my hands, a complete halfcut for $2000 back in '01, so it was very cheap at the time. Mind you it took the next 5 years to get it in my K and running, and then anther year after that until it was engineered etc.

There is such a wealth of information scattered all through the vast number of posts and threads about the 240k, which was the first car I ever owned, and consequently I bought 5 more over the years, a couple of 4doors and 3 coupes. But until the last couple of years I didn't know that they enjoyed such cult popularity or even a following in Australia, so I spend a lot of time reading old posts with interest.

The 2doors are now such a rarity that it is very hard to get parts for them, as everyone knows, and I am still chasing quite a few items for this current k, chrome, badges, etc., maybe even a complete donor car.

Anyway good to see so many people upholding the k's good name, and keeping them alive!