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

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.

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

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!)

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!

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!!

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

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/safety/road/bulletin/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.

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

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!

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!

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.

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!