What is needed to swap a RB into a 240sx? *FAQ*

Discuss the RB20, RB25 and RB26 series engines.
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Coolwhip
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The RB20 and the KA as well as SR tranny all share the same internal gear box.

Length between the RB20 and KA/SR tranny are different lengths and different bolt patherns.

according to some, drilling out holes and what not with custom driveshaft allows you to adapt the KA tranny to the RB. Economical idea? IMO na. But its up to you.

For a RB20 swap you will need a RB20 engine wiring harness and ECU. (Unless of course you use a custom harness and standalone ecu)


ca18datsun510
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can rb20 engine mount brackets be bolted to a rb25 block so you can swap in rb25 with rb20 crossmember?

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DJButton
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ca18datsun510 wrote:can rb20 engine mount brackets be bolted to a rb25 block so you can swap in rb25 with rb20 crossmember?
As far as I'm aware, no. Someone correct me if I'm wrong though.

Adrian gt
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ca18datsun510 wrote:can rb20 engine mount brackets be bolted to a rb25 block so you can swap in rb25 with rb20 crossmember?
you can get a r33 crossmember cheap i got one laying around

ca18datsun510
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i dont have a s chassis .

r33 crossmember isnt so much of an otion.

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HxC_Nismo
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just to let you know the s14 speedo is accurate with the rb25det speed sensor as long as you have 4.08 gears (r33 gts diff, s14 diff, z32 n/a diff) i first had the j30 diff in my s14 with 255-50-16 rear tires and my speedo was -5mph off and since i swapped my rear diff with the z32 n/a diff my speedo is dead on accurate. as for the tach it take about 20 mins. or so to recalibrated but you have to look at your laptop to confirm how off your tach is off but my s14 tach is dead on with my rb26. as for the s13 i have not had the opportunity to swap an rb in yet or attempt to calibrate the tach on those. you can use the rb26 oil pan and it just takes about 1-3 days to modify but it holds more oil and has the proper baffles.heres pics of my rb26 oil pan on my rb26 in my s14 with mckinney mountsyou have to gind the webbings on the bottom of the pan so it clears the crossmember and also on the axle side of the pan you have to grind the webbing of that as close as you can so it can clear the rack and pinion mounts on the s14 cross member. also you have to cut a section on the front of the pan to clear the front sway bar but i chose not to cause i have a custom front sway bar made.


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slo_coupe
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i plan on doin an RB20 swap in my s13 and i have a few questions..... -- if i use the r32 crossmember w/stock or nismo mounts will the RB dump pipe clear my steering shaft?--- if i use mckinney mounts or jgy customs mounts will the dump pipe clear?---will any aftermarket sr20det downpipe work with the stock RB dump pipe?these things just have me all confused because im not sure if i should just order mounts or use the crossmember. im honestly not tryin to fab up any dump pipes or downpipes. Thank you!!!!

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Miyabita_Y33
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funny how everyone says to read the stickies...but the problem is these stickies are not very good. atleast for rb26 information

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DJButton
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Miyabita_Y33 wrote:funny how everyone says to read the stickies...but the problem is these stickies are not very good. atleast for rb26 information
Yeah, the clutter really needs to get straightend out and the facts updated.

brokebimmer
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ive got a auto s13 hatch, and im thinking about buying a r32 rb20 front clip from jdm-online, im pretty much a newb to this, and have a limited budget, any advice, or warnings before i jump into the swap?? all help would be appreciated thx

TheCHosenOne
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I'm tryin to find a job for RB26, but i have to bring in the money first, $5000 is enough

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DJButton
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brokebimmer wrote:ive got a auto s13 hatch, and im thinking about buying a r32 rb20 front clip from jdm-online, im pretty much a newb to this, and have a limited budget, any advice, or warnings before i jump into the swap?? all help would be appreciated thx
Research it some more and do some suspension mods and drive the car a-lot before you swap an engine in.
TheCHosenOne wrote:I'm tryin to find a job for RB26, but i have to bring in the money first, $5000 is enough

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Coolwhip
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For referenece:

The rb20 and the rb25 share the exact same downpipe.

skylinegrl13
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thanks for those pics and info, i am def going to follow your lead. did you use any spacers on your mounts?

I am having a lot of fitment issues with my mount kit. Mack from McKinney is sending me new isolators since I have an older version of the kit, also pics of their oil pan mods which I will post here. FYI the McKinney kit is made to accomodate the RB25 pan, and "spacers" are required to fit the 26 pan. Wish they had mentioned that when I bought the damn thing.
Modified by skylinegrl13 at 1:16 PM 1/8/2008

JDM-Silvia
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I have a question about swapping a RB25 into a 180sx.. Seeing that it's RHD, do I need to get anything different compared to a LHD 240sx install?

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AreszONE
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My question is.....I have the front clip for the RB20 and the was wondering if the hubs and suspension from the R32 will bolt up to my s13. Also you said to change out the suspension could I possibly use the R32 suspenison, and the belts and spark plugs issue will I need to replace the OEM ones. Lastly I'm guessiong the fenders and hood from the R32 will not bolt directly up to the s13 and wondering if anyone had any information on how much modification you would have to do in order to make them fit, because I plan on doing the R32 conversion on my Hatch. Thanks for any info that can be given it is much appreciated.

thrashingdeath
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Can the R33 crossmember be used for the RB20 swap?

Fatwired240
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I need this answered also.

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AreszONE
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bump

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Khash
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great post hopefully get a rb in my s13 soon

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koukicody
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sigh. quick dumb question. i thought i remember reading that if you use the r32 x-member for a rb20 swap in a s13/s14 you wont be able to use the s13/s14 front swaybar.

is this true and if so, is there a fix for this?

just wondering for my own info and to put the info out there for everyone else.

j2549k
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i need a wire diagram for my rb20 so i can put it in my 240sx and i need to see a bracket pic of the trottle cable if some one can help please email me at [email protected] thanks

zdonner
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RB26DETT Swap to a S14;RB26DETT - $3400 est.Z32 Tranny Mated to RB26 Bell housing - Bell housing - $0/Tranny - ~$350 est.Custom Driveshaft - $300 estRB25 Oil Pan - $169.99McKinney Mounts - $550McKinney DP(s) - $500Radiator (Aftermarket) - ~$300 TypicallyRadiator Hoses - $115Electric Fans - $225 estThermostat - $70 estTach Adapter (Personally going to send my cluster to LS Automotive or use a Skyline cluster) - $XXXFront Mount Intercooler - McKinney offers piping + Core + couplers and T-bolt clamps - $850Clutch - Many optionsO2 Housing Adapter - $80 One of those "Why not?" sort of thingsWiring - ~$359 to have it done professionally

Misc Maint:Water Pump - $89.99Oil Pump - $289.99Timing Belt + tensioner ect - Belt $125 Greddy/Tensioner $149.99Spark plugs - $20 estAccessories belts - complete guess $50-$100Speed Sensor - $XXXOil + Filter - Personal preference

Total$8043.96That's not a complete total as you can see as well as it does not include shipping on any items. Nor a exhaust system or any extra items.

I've been toying with this idea or a RB25 for a while now and there is not much of a difference in overall cost, the RB25 motor set might save you about $1000, and the DP would be about $100 cheaper, you won't need the oil pan and you won't need another transmission but if you're going to spend $7000+ what's another $1400; Twin Turbos .1 L of displacement, one bad-*** engine and some bragging rights

To acquire the parts and drive the car down the road this should do it, I may be forgetting something so let me know.

This is a list that balances low cost with quality parts so not cutting any corners but having shopped around A LITTLE. If anyone can add to this with better prices please let me know.

twofortyridaS13
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To those that have swapped an rb20 into an s13 kade. So whats the best route, r32 crossmember, mckinney mounts, or in house setup? Mckinney is going to cost the most. In house cheapest but pain in the ***. R32 xmember not too expensive and less pain. After reading all these rb threads nothing is clear mounting the engine other than I know the 20 is the way to go for me. I just want to know what you did and how well or not so much it worked for you. If you went custom do you wish you had got the mckinney mounts? Or if you bought mckinney do you wish you had gone r32 and saved a few bucks? I just need some clarification on this. Thanks

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Coolwhip
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I've used all mounting methods listed for various RB's. Just go OEM xmember.

twofortyridaS13
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Forgive me for sounding like a noob but I just started seriously considering the rb20 for past 2 months(was on zilvia/ka-t for 1.5yr)For the sake of my pockets or mental health? Or both. Which rbs have you done?

I just realized this makes no sense and i have forgot where I was going with it so delete it please. Thanks.
Modified by twofortyridaS13 at 10:57 PM 5/1/2008

grayWATERS
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Which one is the best to do r32 x-member and stock mounts, or ka x-member and mckinney mounts???

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DJButton
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R32 x-member and stock mounts best way to go, no question about it.

1990tsi
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I am almost finished an RB20 swap, I will give my pointers, as every swap seems to be different.

I started with a wrecked skyline, paid $1000cdn for everything.

My swap is a little different, as I started with an automatic sohc 89 coupe.

I'm using R32 x-member. Fits pretty well but my turbo elbow won't clear on the steering. 6 bolt turbo flange seems hard to come by. I'm looking into a custom one, but first I will be taking a grinder to my stock elbow (have 2 spares, not hugely concerned about wrecking one)Motor does sit high, so far my hood won't close but only hits on the PCV outlet hose. once I have that figured I'll know what else I have to notch out.X-member difference for anyone curious

Throttle cable plate people are talking about - My donor skyline had cruise control and I was able to slightly bend the 'other' cable holder so my stock S13 throttle cable fits and works perfectly. Maybe dohc S13s have different throttle cables, or non cruise control Skylines have different cable holders (the one on the manifold)pic

speedo signal- skyline uses a cable for the speedo, S13 uses an electronic signal. I am not entirely sure on the fix for this, I'm assuming the dohc sensor fits the RB20 transmission. What I can guarantee is that the AUTO sohc speed sensor does not fit in the RB20 tranny. I'm picking up a dohc 5 speed sensor this week and will find out!

wiring- I used this guide and it was pretty helpful http://www.nicoclub.com/articles.php?id=225177

Wasn't perfect though. I had no power to my coilpacks when I was done. I found the main power wire for the coils (fat white wire) and followed it to the cabin, through the firewall. It was on one of the 2 green plugs. This wire needs ignition power and when I unplugged my harness I didn't take whatever was plugged into those green plugs! Found 12v ignition coming from another wire in the 2nd green plug and *temporarily* hooked that up to start the car. I will be running a fused line to it when I'm finished the swap.

auto-5 speed swap. I used this guide http://www.nicoclub.com/articles.php?id=183606

and it helped me out quite a bit, but still had one little issue. My key wouldn't come out.plugged the auto shifter back in and figured out which wires triggered the park switch and jumpered them. all of a sudden it clicked and my key came out!Wires in question for anyone else in my shoes

yellow/red and blue/black get spliced for the key fix.

1990tsi
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Quick update:DOHC S13 speed sensor does fit into RB tranny 100%

Power steering lines are not fun to install if you have a SOHC and want to run DOHC lines. X members are different enough to make it a pain in the *** to hook up properly even with a DOHC resovoir. It's do-able though.

Hood hits on PCV line and intake manifold, small spot on intake mani where TB bolts up.


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