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:classic: ) 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. :cheeky:

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:classic: ) 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.